Shading and Windbreaks
Shading and windbreaks can play a large role in the energy efficiency of both your heating and cooling systems. Shading the exterior of your home in the hot summer months can help keep heat from building up on the interior and wind breaks can be beneficial in the winter months to help block harsh north and north west winds that pound on your home. This is important because the wind affects the amount of heat loss, comfort and durability of your home. Shading typically comes from large trees located near your home but other buildings can also provide shading. The main thing we are trying to accomplish is to limit the amount of solar heat gain in the summer months. Most of this heat gain will be coming in through the windows. As the sun moves across the sky we will get morning light in the east windows, mid day light in the south windows and late afternoon light in the west windows. The morning light we get in the east windows is considered desirable by many people but it still is a heat gain on the house. West windows are nice for watching the sun set but think about when we have the hottest parts of the day, they are usually in the late afternoon. West windows can really produce a lot of heat. Trees or the overhangs on the house can easily shade south windows. The sun is high in the sky on those midsummer days so a decent overhang above the south windows will do a lot of shading. We can’t accomplish much shading with overhangs on the east or west because the sun is either rising or setting and is low in the sky. Windbreaks work best when they are located some distance from the house so they deflect the wind up and over the roof. They can also be affective in controlling snowdrifts. It’s important that windbreaks are at least 15 feet from the house; closer and you actually trap heat that increases summer cooling costs. Many farmsteads have trees (usually pine trees) planted around the northwest corner of the property. This is a classic example of a windbreak. In urban areas, windbreaks can come in the form of buildings, landscaping and fences usually provided by the neighbors. Check out the Arbor Day Foundation web site for detailed information on how to plant trees for shading and windbreaks. www.arborday.org Do two separate searches one for ‘windbreak’ and one for ’summer shading’. Remember we are in hardiness zone 5 when you select trees. Take a walk around your house and see what you already have that might be beneficial for shading and wind breaks. On a sunny midsummer day take note of the sun that enters your house in the morning, mid day and evening. On a windy day, go outside and observe how strong the wind blows around your house. Long term The long-term goals would be to create a future windbreak and some future landscaping that would eventually provide summer shade. Any landscape plans should include consideration of how it will affect the sun and wind exposure on the house many years later. Short term If you have plenty of space on your property, some reshaping of the grade could be done that may deflect wind. Some fencing in the right place could also help. To help with heat gain, you may add awnings over the windows on the south face of your house. On average a 30” shade over the window will do a great job of shading in the summer yet let sun light in during the winter months. On the east and west side you can use your interior drapes and blinds to cut down on the amount of heat gain. One thing we don’t think about much these days is the idea of exterior shutters. Many homes have ‘fake’ shutters for looks but there was a time they served a purpose. Shutters on east and west windows control the heat gain at the exterior before anything enters the house. Shutters can also be used to add a layer of insulation to the window, protect the windows from storm damage and add a layer of security. Wouldn’t that be fun to have something so low tech yet so effective on you home?
Shading and windbreaks can play a large role in the energy efficiency of both your heating and cooling systems. Shading the exterior of your home in the hot summer months can help keep heat from building up on the interior and wind breaks can be beneficial in the winter months to help block harsh north and north west winds that pound on your home. This is important because the wind affects the amount of heat loss, comfort and durability of your home.
Shading typically comes from large trees located near your home but other buildings can also provide shading. The main thing we are trying to accomplish is to limit the amount of solar heat gain in the summer months. Most of this heat gain will be coming in through the windows. As the sun moves across the sky we will get morning light in the east windows, mid day light in the south windows and late afternoon light in the west windows. The morning light we get in the east windows is considered desirable by many people but it still is a heat gain on the house. West windows are nice for watching the sun set but think about when we have the hottest parts of the day, they are usually in the late afternoon. West windows can really produce a lot of heat. Trees or the overhangs on the house can easily shade south windows. The sun is high in the sky on those midsummer days so a decent overhang above the south windows will do a lot of shading. We can’t accomplish much shading with overhangs on the east or west because the sun is either rising or setting and is low in the sky.
Windbreaks work best when they are located some distance from the house so they deflect the wind up and over the roof. They can also be affective in controlling snowdrifts. It’s important that windbreaks are at least 15 feet from the house; closer and you actually trap heat that increases summer cooling costs. Many farmsteads have trees (usually pine trees) planted around the northwest corner of the property. This is a classic example of a windbreak. In urban areas, windbreaks can come in the form of buildings, landscaping and fences usually provided by the neighbors.
Check out the Arbor Day Foundation web site for detailed information on how to plant trees for shading and windbreaks. www.arborday.org Do two separate searches one for ‘windbreak’ and one for ’summer shading’. Remember we are in hardiness zone 5 when you select trees.
Take a walk around your house and see what you already have that might be beneficial for shading and wind breaks. On a sunny midsummer day take note of the sun that enters your house in the morning, mid day and evening. On a windy day, go outside and observe how strong the wind blows around your house.
The long-term goals would be to create a future windbreak and some future landscaping that would eventually provide summer shade. Any landscape plans should include consideration of how it will affect the sun and wind exposure on the house many years later.
If you have plenty of space on your property, some reshaping of the grade could be done that may deflect wind. Some fencing in the right place could also help.
To help with heat gain, you may add awnings over the windows on the south face of your house. On average a 30” shade over the window will do a great job of shading in the summer yet let sun light in during the winter months. On the east and west side you can use your interior drapes and blinds to cut down on the amount of heat gain.
One thing we don’t think about much these days is the idea of exterior shutters. Many homes have ‘fake’ shutters for looks but there was a time they served a purpose. Shutters on east and west windows control the heat gain at the exterior before anything enters the house. Shutters can also be used to add a layer of insulation to the window, protect the windows from storm damage and add a layer of security. Wouldn’t that be fun to have something so low tech yet so effective on you home?
Exterior Water Management
Exterior water management in homes built during this time frame consisted of mostly grading your property so surface water moved into a gutter or ditch as fast as possible. Houses in developments and subdivisions were beginning to be built closer together making the water ways between the homes narrow and steep. In later homes, sump pits with pumps were added to remove water that collects around the foundation and under the basement floor.
Now let’s take a look at what you have:
Start in the basement and take note of any areas that are damp or look as though they have been damp in the past. Be sure to pay careful attention to the location(s) in the basement where you are seeing signs of moisture. Look for a sump pit with a pump in it. If you do find one, make sure it has a lid and it is sealed for radon and soil gasses and take note of where the discharge line goes.
Now let’s go outside and have a look around. Walk around your home and take note of the height of the dirt next to the house and to about 10 feet away. It’s not unusual for the dirt in the area around the house where the foundation was excavated to settle some. Take note of which direction the ground slopes, toward the house or away from the house, and how much difference there is in height. As you’re walking around, also note where the downspouts from the gutters dump out and which way the water would likely run. Another thing to look for are where there might be high volumes of water coming off the roof at the valleys.
Next we’ll walk around the property looking at the grade beyond the house. Are there areas where water will pool after a rain? Does the neighbors’ house sit higher or lower than yours and does any of their property slope toward your yard? Where does the water go when it leaves your property?
The last thing to take note of is your hard surfaces such as the driveway or a patio. Note how much of your property is covered with hard surfaces and where the water drains to.
Draw a map of your property showing the directions the water flows around your home.
Our goals here are fairly simple, we want to have good drainage around the house so the basement stays dry, and we want to keep as much of the rain water on the property as we can (I know this sounds crazy but be patient, we’ll explain).
We’re going to deal with the drainage in two steps. First we’ll work with the area around the house and next we’ll work with the rest of the yard.
- The grade around your house should slope away from the foundation at least six inches in the first ten feet. It’s very important that water coming off the roof and from around the house do not pool next to the foundation. This may not be so easy to do if the landscaping is thick and mature. Do the best you can. If you’re having water problems in the basement adjacent to a low area in the grade, the landscaping will have to be removed so the grade can be corrected. It’s not just the dirt areas we’re concerned with, you also need to consider any concrete walks or patios that run along the house. They may have to be raised or replaced to keep water moving in the right direction.
- Now the gutters – who loves gutters? Not us, we think they’re a pain in the kiester. Generally they are an evil necessity unless you have very deep overhangs on your house, (three feet or more) and you could possibly remove the gutters. The gutters have to be clean to work; there is no way around this. Gutter toppers seem to do well in light rain but when you really need the gutter to perform (in a heavy rain) you better have as much open space to catch water as possible. It’s best to try to eliminate the source of plugged gutters, which is leaves, sticks, walnuts, etc. Prune the tree limbs that hang over the house to help reduce the leaves that fall on the roof. If you must use a topper, try the removable, open screen type that lets as much water in the gutter as possible yet can be flipped up to allow for cleaning. If you have a large roof, you may want oversized gutters or if there are water problems in the basement, in the corners where a roof valley dumps a lot of water, you may need to put a splash flashing on the gutter to help keep the water from overflowing.
- Next the downspouts: The best situation is an oversized downspout that dumps on a splash block that guides the water away from the foundation by at least four feet or more. An oversized down spout will pass debris better and using a splash block instead of more down spouting as a leader is easier to take care of. Leaders (extensions) tend to get smashed or disconnected and then the whole system is compromised.
- Now let’s talk about something fun – water collection. Collected rain water can easily be used for watering gardens and landscape plants. If you would like to collect rain water use a rain barrel and collect from one of your down spouts. Or if you want to collect more than a rain barrel can hold, you can make your own water collection cistern. This water is not to be used for drinking. Collected rainwater can easily be used for watering gardens and landscape plants. The old cisterns had a hand pump mounted above them and you can still find these at auctions and in Grandma’s barn. If you don’t want to pump the water by hand you can use an electric pump to do the same thing. If you don’t have a cistern but would still like to collect rainwater, use a rain barrel or make your own cistern. You will be surprised at the amount of water you can potentially collect. For a simple calculation take the square footage of your home and multiply by 32 (rough average of yearly precipitation in inches) then divide by 12 (gives you cubic feet of water) and multiply by 7 (number of gallons in a cubic foot). Example – 1000 square foot house x 32inches divided by 12 equals 2667 cubic feet of water times 7 gallons per cubic foot equals over 18,000 gallons. WOW! If you live in town, be sure to check with your water utility for any restrictions on the amount of water you can collect; there may be rules you need to follow. www.rainwatercollection.com
Now for the rest of the yard. Our main objective is to keep as much of the rainwater as we can on the property. In town, most of the time runoff heads toward the street to the storm sewer and dumps in the local river or stream. In rural areas, the water heads to the ditch and eventually to the river as well. Along the way it picks up yard chemicals, pet waste, gas and oil from the road, and other garbage along the way. This is not helpful to Iowa’s rivers and streams. Besides, don’t we want to keep as much water on our property as we can to nourish our plants?
- The first thing we want to do is reduce the amount of impervious surface (typically concrete) we have on our property. In homes of this era it’s not uncommon to have a gravel driveway or possibly two narrow strips of concrete to drive the car on. This is good, resist the temptation to pave the whole thing if you can. If you feel the need to have some hard surfaces around your home consider pervious concrete or brick pavers when it’s time to replace the concrete. Both will let water soak through with less runoff. Caution – pervious paving may allow water to drain toward the foundation.
- Second, look for a good place to install a water garden. This may be that low spot you saw when you were assessing the land, or pick a place where there is a high concentration of water moving across the ground during a period of rain. These could be good spots to collect a significant amount of water. If you are not collecting roof water in a cistern you may want to divert the downspouts via a tile to the water garden. One note of caution though; – don’t locate your water garden where it will cause trouble with your foundation. It should be located at least 50 feet away from the house. www.rainscapingiowa.org
- If you don’t feel you can keep your rain water on your property, at least try to slow it down so it has time to soak into the ground well. Think about how the native prairie slowed and filtered the rain water before it made its way to the rivers. Native plantings in your yard are always a good choice and some strategic landscaping could help slow down the water flow.
A good resource is EEBA’s (Energy & Environmental Building Association) Water Management Guide. www.eeba.org
Now that you’ve finished this section, take some time to fill out this questionnaire to assess your home’s exterior water management. Keep it with the other questionnaires to build a resource you can reference when tackling projects at home.
(Let’s find out what you have)
There is wide variety of windows that have been used on Iowa homes in this time frame and their quality and efficiency can vary a great deal. Let’s figure out what type of windows you have first. The two most common types would be double hung and casement. A double hung will consist of two sashes with glass, one above the other. You can operate a double hung by lifting the bottom sash up. In many cases you can move the top sash down too. A casement window is hinged at the top and bottom of the frame and usually operates with a crank that swings the window out. A third type is awning and it operates much like a casement except the hinge is at the top and the window swings open from the bottom. The last type you may have is a sliding window which is just as the name implies, it slides side to side to open and close the window (kind of like a double hung laying on its side).
Now let’s look at the exterior: Mostly you will see wood frames and wood sashes. You may also see an aluminum storm window (some people call them combination windows) that has been installed over the original house window. (More on that later) Some of the later windows may be wood covered with metal or aluminum. Look for signs of wood decay (soft wood), in windows covered with metal. It may be harder to see but it’s still possible the wood behind the metal has gone to pot. Look at the joints and edges for swelling.
Okay, now put your head against the glass and look down at the connection of the glass to the sash. You should be able to see how many layers of glass your windows have. You will see either one or two panes of glass. If you see two panes, try to determine what material is between the two panes. It would either be wood or metal, or it could be the glass actually rolls right around from one pane to the other. If you have two panes of glass, note if they look clear or if there is a haze between the panes.
On the interior, check the hardware to make sure it is all there and the window is working properly. Sometimes the brand of the window is printed on the hardware – take note. When you open the window you have another opportunity to check for wood decay on the window frame and the sash edges.
See if you can determine how the window is weather stripped. This may be a flexible strip on the frame or sash or both. Check the condition – these strips may have worn out over time, have missing pieces or have been flattened to a point where they don’t do much good.
If you have the aluminum storm windows, do the same and check as you did with the house windows. Note especially broken glass, torn or missing screens, broken corners, and the small tabs that act as a latch of sorts. There is a weather strip on this type of storm so check it out as well. Note also if the storm window has been caulked to the window frame and if the drain holes at the bottom of the storm window are caulked closed. Since you are right there, if they are caulked closed, open them up.
What we want to do is take your existing windows, make them operate smoothly, repair wood decay and reseal them. Remember, replacing windows is expensive and the amount of energy savings you get is not likely to justify the cost. Like we mentioned, there were a lot of different qualities of windows produced in this era and some of them haven’t held up well. These may need to be replaced. There are also some very good, well-sealed and insulated windows that were produced. Don’t be talked into replacing a window that was well built, it just needs some tuning up.
- The first thing you need to do is if you know the brand of window, check to see if you can get replacement parts or if they have a service department. If there is service available, it would be a good idea to consult with the service technician first before you start repairs by yourself.
- If you have rotted wood and it has not progressed to the point where the window is falling apart, you can remove the decay and install patches of either wood or catalyzed putty purchased at your local hardware store. Some parts may be able to be replaced by the manufacturer if available.
- If you have a double glazed window and the glass is fogged it, will need to be replaced unless the two panes are separate pieces that can be removed and cleaned. Usually a fogged glass means the seal has been broken and the gasses trapped in the sealed glass have escaped. If the glass can be removed it can be replaced by your local glass store – give them a call. Sometimes the glass and frame (sash) are integrated and the whole thing has to be replaced. You’ll need to call a supplier of that brand and see if you can get a replacement.
- Hardware can be lubricated and screws tightened. Sometimes there are adjustments in the hardware that can make the sash fit better in the frame if there is rubbing.
- If you know the brand of window, you may be able to order new weather strips to get that ‘fresh out of the box’ seal.
- If you’re ambitious, remove a piece of trim from the inside and see if the space between the window and the wall stud is insulated. If not, you can add some window spray foam to insulate and seal that space. (often a source of that nasty draft you feel) Caution, read the label, take it seriously; don’t overfill!
Aluminum storm windows
- Check with your hardware store for replacement parts. Often they are still available, Hurray! And some hardware stores will do your repairs for you, Double Hurray!
- If you want to do it yourself go ahead. Not recommended!
Now that you’ve finished this section, take some time to fill out this questionnaire to assess your home’s windows. Keep it with the other questionnaires to build a resource you can reference when tackling projects at home.
Insulation and Air Barrier
(Let’s find out what you have)
Iowa houses during this time frame went from having very little if any insulation to being quite well insulated. Some may have a couple inches of vermiculite or rock wool in the attic (If you think you might have vermiculite insulation follow this link for more information: http://www.epa.gov/retailindustry/buildings/insulationbrochure2-1.pdf); others a foot or more of cellulose or fiberglass. The insulation in the side walls could be a couple inches of rock wool on a paper backing or anywhere from 4 to 6 inches of fiberglass batting.
A peek in the attic will tell you what you have. Be sure to look all the way down to the bottom because you may have a couple different types of insulation that have been added one on top of the other. Measure the thickness of each layer so we can determine the R-value of the whole insulation job.
While you’re in the attic let’s look for signs of an air barrier. One place to check is at a location of a light fixture on the ceiling below. Pull the insulation back and see if you can see light or feel air coming from around the electrical box. It’s a good bet you can. Does it look like there is a plastic sheet on the ceiling of the room below? This would be a vapor retarder and not many houses put them on the ceilings in this time frame but some did. Make a note of what you observe.
The walls can be a little more difficult to determine what you have. Here are a couple of things you can look at to help. From the attic, sometimes you can see into the wall cavity near the roof edge. This can be tough to get to especially if you have to crawl through the attic insulation. Another way to check is remove an outlet cover on the exterior wall. Sometimes there is extra space around the plaster where the electrical box pokes through and you can see into the wall cavity. This is also a good place to check the air barrier. Look for the plastic sheeting again. (More likely on the walls than on the ceiling) You may be able to feel air movement around the outlet box but not necessarily. Sometimes a foam gasket has been placed behind the outlet plate cover to help stop a drafty outlet. Lastly, in a closet or some other inconspicuous area, remove a baseboard and cut a small hole in the drywall behind where the base would be to have a look.
One more way to check wall insulation is to take a long small diameter twist drill bit and drill a small hole into the wall in a place that does not matter. Examine the dust and stuff the drill brings out to see if there is any insulation in the mix. This will only tell you the type, if any, of insulation, not how much you have or if there is a plastic barrier on the wall.
Let’s also take a look at the boxing or rim joist area (framing area on top of the basement wall) in the basement. This area is exposed to the outside too. Most commonly there will be pieces of fiberglass batt insulation fit between the floor joist, if there is anything at all. Make a note of what you see. Check for an air seal in this area too. Turn the lights out and look for light from the outside; you may be surprised at what you see. If it has been sealed, you will see caulking at the joints where two differing pieces of weed meet. Gaps may have been caulked but it’s pretty rare to see that.
While we’re in the basement, you will note that the walls and the floor are not insulated. Okay, maybe the walls have something but unless it’s a finished basement I bet not. Crawl spaces are not as common as in earlier houses but if you have one, note the walls and boxing area just like the rest of the foundation. The floor of the crawl space should be noted too if it has a concrete floor or is exposed dirt.
Now you know your type of insulation and the amount; let’s figure your R-value. Use the chart below to calculate your R-values in the walls, ceilings and boxing/rim joist.
|Material||R-value (per inch)|
|Vermiculite||2.1 (asbestos based product )|
|Spray Foam||Seek a professional!|
(there are other issues here)
*Vermiculite can be tested for asbestos at the University of Iowa lab.
There is some testing you can do to help determine how well your house is insulated and sealed. One – you can have a blower door test done on your home (do not do a blower door test if you have vermiculite in your home). An energy rater usually does this; preferably a HERS certified energy rater. The blower door (an insert temporarily installed in an exterior door frame with a high volume fan attached) will pressurize your home and accentuate the air leaks. Just feeling around outlets, doors, windows and plumbing pipes you can find many of the air leaks in your home. A smoke tool can also be used to visually see the leaks when the smoke is released near an area you’re checking. The rater can also run a calculation on your home to determine how much air is leaking from your home. This measurement is in Air Changes per Hour (ACH). There are two numbers you can get, – one is ‘ACH natural’ which is the amount of air that exchanges in your home without any fans or other pressure. This is not the best number you can use; a better number is ‘ACH 50’. This is the number of air changes in your home when it’s under pressure with the blower door fan. If you want, most raters can tell you approximately how big a hole you would have in your home if all the air leaks were put together in one place. Don’t be surprised if it is pretty big, like a hole four foot square.
The second test can also be done by your certified HERS rater (ask for a copy of their certification certificate). This test uses an infrared camera to show images of temperature differences in the walls and ceilings of your home. The images will help you determine weak spots in your insulation. Copies of the images will be useful as you make improvements to your home. It’s a good idea to have the rater help you interpret these images because sometimes they show weird things like your silhouette on a window. It is also best to do this when there is a large temperature difference between the inside and outside of your home.
Lastly, ask the HERS rater about combustion air for your furnace, water heater and any other appliance in your home that burns fuel. Your home may leak air enough to feed the flame and draft the flue pipe but as you seal up your home this could become an issue. Talk about your plans to improve the insulation and air seal. Find out how they would like you to monitor your combustion appliances as you tighten up your house.
Ultimately we want to have a tightly sealed building envelope with an adequate amount of insulation. Here we can work with numbers; let’s aim for a building with an air change per hour of 3 ACH 50 or less. This would be a very tight building and will require some effort to achieve. On the insulation side let’s try for an R-15 on the basement walls, an R- 20 on the other exterior walls and boxing areas, and an R- 60 in the attic. We’re not kidding when we say if you can get to these goals, you will be living in a very efficient house, an extremely efficient house, maybe the best house on your block. We should pause and think about this a little because it sounds like a lot of work. What is the benefit of going to all this trouble? Well, if we spend our time and money on doing this right, of course our energy bills should be lower; that’s good. We also can use smaller equipment to heat and cool the house, which is also good. But let’s think bigger…. Everyone who follows you, as an owner of this home, will benefit in lower operating costs and no matter what energy source is used in the future, this house will demand less from our planet. Now I’m feeling good!!!
If we’re going to do this right we have to think about a whole slew of other projects: Siding, duct work, wiring and plumbing, bath vents, door and window seals, indoor air quality, back drafting and more. In the big scheme of things, insulation and sealing may be a project that comes later down the road. It’s always temping to take that energy rebate from the utility and blow in a bunch of insulation in the attic right away, but that is possibly the worst thing you could do.
So here are the steps, they may not all apply but the order is very important.
Note: If you have vermiculite in your attic, this is a special situation and a trained professional should do all the work since this is an asbestos based product!
- We are taking a top down approach so we’re starting in the attic. There are several projects to do before any insulation goes down and we actually want you to take any insulation you have in the attic out! You may be able to roll up the insulation if it’s in batts, but most likely it’s some type of loose insulation. The easiest way to deal with this is to have the blow-in insulation guy come out, reverse the operation, and suck out the insulation (depending on what you have, it may be reusable). Now we have a nice clean attic to work in.
- Any bath or kitchen exhaust fans that are venting in the attic space need to be vented up and out the roof, out the sidewall, or through the eve or overhang. If the overhang or eve is vented, then they cannot be used for venting. All vent pipes need to be sealed and insulated. This prevents condensation from dripping back into the house. Metal rigid pipe is best, metal flex pipe is okay (not great) and please don’t use plastic flex pipe. Seal the joints with mastic (not tape). If you have any plans to add a vent, now is the time to do it. You don’t want to be crawling around in your newly insulated attic messing things up later. The reason we are doing all this is because we don’t want to add any additional moisture to the attic once we’re done; which air leaks will do.
- Next, any plumbing vent pipe coming through the attic needs to be checked out. Hopefully they are in good shape but if not, they need to be replaced now. And the new pipe needs to go through the attic floor (the ceiling below) so we can make a good seal around it in the attic space. Here comes a special secret detail – as the plumber is fitting the pipe, before he attaches it to the pipe below, slip a piece of rubber roofing with a hole cut in it over the pipe that will act as a gasket. Once the pipe is attached, slide the rubber down to the attic floor and attach it to the wood plate the pipe comes through. Plumbing pipes move up and down with temperature changes and this seal will stay in place as the pipe moves.
- Look around for any metal pipes coming from below that could be hot (warm) like from a fireplace, water heater or furnace. There is usually a requirement that there be at least a two inch space around this pipe of non-combustible material. To make a seal you will need to fit some sheet metal around the pipe and caulk it with high temperature caulking. Be sure to caulk the seam in the sheet metal as well. Don’t worry about caulking the sheet metal to anything else. Now you need to build a box or cage of sheet metal around the pipe to hold the insulation back two inches. Note: not all metal pipes need to be treated this way. Some are rated for insulation contact; you will have to determine what you have. If you’re unsure, put in the air space just to be safe.
- If your house has been remodeled, there may be some electrical junction boxes in the attic. Make sure all the wiring in the attic is in good shape and meets code. You may need to have your electrician come and take a look. He would rather fix it up now than when your attic is stuffed with insulation.
- Recessed lights that have been cut through the ceiling and stick up into the attic space may need to have an airtight box fit over them unless they are in an ‘air tight housing’. Allow at least a one inch space over the top of the light and notch the plywood as needed around the wires so the box sits nicely on the attic floor. It can just sit there; no need to fasten it.
- This step is for you folks with the plastic vapor retarder on the ceiling. We’re going to use this as our air barrier. All the things we’ve worked on so far go through this plastic sheet. We need to pull the insulation back from around all these penetrations and seal the pipes, wires, fans, recessed lights and anything else that pokes through the plastic. You can use caulks, spray foam, mastic; whatever will stick to the plastic and hold up well over time. Also, wherever there is a ceiling light fixture in the rooms below, there will be an electrical box sticking through the plastic. You may have to hunt these down because they will be buried in your insulation. And lastly, the interior and exterior walls below (you’ll see the top plate from the attic) will need to be sealed to the plastic as well. We know this sounds like a lot of work and it’s a really crappy job crawling around the insulation, but do the best you can. A well sealed attic can stop ‘the stack effect’.
- Attics need to be vented. There are a couple of ways this is done. In your home, it may be a louvered vent in the gable ends of the roof. Most roofs have vents in the soffits that work with vents in the roof peak or near the peak. If you have good gable end vents that are in working order you’re set. If not, you need to make plans to add soffit venting and ridge vents. This is a project that will be done from the outside. Right now, in the attic, you need to make sure that the insulation you add won’t impede the flow of air from the soffit vents to the ridge vents. This is done with something called a ‘proper vent’. They are usually made of plastic, cardboard or Styrofoam. They come in a couple of different widths and are usually about four feet long. All types do their job well. I would pick the cardboard just because it’s more organic than plastic or Styrofoam. These vents are placed in every rafter space over the exterior wall plate, extending into the attic and stapled to the underside of the roof sheathing. Be careful not to squash then; remember we want air to flow.
- Prepare the attic access. If we step back and look at how we get into the attic, it’s pretty obvious that it’s just a big hole in the ceiling. You may even have a stair that walks right up there. The first step is to put an insulation barrier around the perimeter of the hole that will hold back the loose insulation and keep it from rolling down the hole. This usually is made of plywood strips about 12” to 14” tall. The second step is to make a cover for the hole that can be sealed and insulated yet easy to remove.
- Some of you may have heating and cooling ductwork in your attic. This requires special attention and we will refer you to the ductwork section of HOME MATTERS for specific information. The important thing to know is unsealed ductwork creates problems of all kinds and flex ductwork does not always work the way it should. So, please don’t skip this step! (Include pictures of unsealed and flex ductwork)
- Now you have an attic that is prepped for a proper insulation job. If you have the plastic sheeting, you can skip this step, although the part about using foam at the exterior walls may interest you. The first step is to have your insulation contractor apply two inches minimum (very important) of high density foam or 1.9 Lb foam (also very important) to the entire attic floor. Plus we want this spray foam to fill the entire area over the exterior walls all the way up to the roof sheathing and proper vents so that we have a thicker layer of foam where we don’t have much space for insulation. The spray foam should be continuous going up and over any recessed light boxes, ductwork, bath fans, and around plumbing pipes, and anything else coming through the attic. This is going to do three things for you; all really important.
- High density foam has almost an R7 per inch of foam, a lot of R value per inch. This will give us a much better R value over the exterior walls which are usually a very weak area of the overall insulation job.
- The continuous layer of foam will create a complete air barrier in the entire attic space. No air leaks!
- Using the high density foam also creates a vapor retarder that keeps moisture from entering the attic space and collecting in your insulation. This can show up as a water stain on your ceiling and it can ruin the R value of your insulation. If all has gone well, we have about an R14 in the attic so far.
- We’re going to add a project here that’s not related to the attic. Because we have the spray foam contractor here, let’s take him/her to the basement and apply a 3” layer of foam in the boxing area to insulate and seal it up. It’s not as critical to think ahead in this area because it’s pretty accessible (unlike the attic) and it can be repaired with canned spray foam if a future hole needs to be added.
- The last step is to finally add the blow-in insulation we wanted to put in way back in step one. Cellulose is the preferred insulation. It’s made from recycled paper and holds it’s R value well over time. We want to get to an R60. If you used the spray foam, we have about an R14 so we need to add about another R46. If you left your original insulation in place, you can subtract the R value you have from 60 to determine how much more you need. Notice we’re not talking about how many inches we need to add; that’s because to get to the R value we’re after, we need to add a certain number of BAGS of insulation. Right on the label it will tell you how many bags per 100 square feet you need to get the R value you want. Make sure your insulator knows you expect X number of BAGS to be installed in your attic (not inches) based on your square footage. Note: you could do this step yourself with some rental equipment but its best to check the pricing on hiring the job done as it may not be worth the trouble to do it yourself.
That was intensive to say the least but a job well done!
Two additional topics related to attic insulation:
- Vaulted Ceilings: You may have some rooms in your house that have vaulted ceilings and insulating them can be a challenge. Many times there just isn’t enough room to get a decent amount of insulation in the space between the sheet rock and the roof. It also can be difficult to get to. One way to get access to the vaulted spaces is when you replace your roof shingles. When the old shingles are torn off and before the new shingles go down, you can remove the plywood roof sheathing and add insulation from above. Use insulation with a high R value per inch since you don’t have much space to work with, possibly only five or six inches. Try to use a system that does not require venting so that you can fill the whole space. One other thing to consider is adding a layer or two of high density foam board to the ceiling from the underside. You can gain about an R5 for every inch you add and you will be creating a complete thermal break. Unfortunately you will have to put up new sheet rock over the foam.
- Conditioned Attic Space: Some people really like their attic storage space; we don’t. A modern attic should be for insulation only and if it is sealed and insulated properly, there is no reason you should need to be up there. However some homes do have good attics with floors strong enough to hold a load, enough headroom to stand up in and a decent stair to access it. In this case you should consider insulation in the rafter spaces rather than on the attic floor. There are insulating systems you could use that would do a good job of insulating and sealing the attic rafters and some do not require venting. If your attic is important to you as storage space, a conditioned attic space is what you need.
Whatever your situation is, remember to take care of the venting, repairs, and air sealing before you do the insulation.
fiberglass batt insulation
mastic sealed duct work
spraying attic to seal
cardboard proper vents
attic door cover
conditioned attic space
We are ready to talk about the sidewalls, and the basement.
Our two objectives here are to insulate and air seal. If you already have some insulation in your walls, even if it’s not as much as you wish you had, you should accept it as it is and focus on more important areas like air sealing. If you do need to insulate, there are a couple of things to consider before you insulate: If you are planning an interior renovation that will expose part of the exterior wall cavities, you can approach the insulation from the inside in. If you’re planning on residing your home, there are some added steps you can take for even better results. This is a job you will have to hire an expert insulation installer for.
Here are the steps:
- The first thing you should do is to team up with a reputable insulating contractor who has a variety of products you can select from. Have them out for a look and a discussion about your installation options. Remember those infrared camera images you saved? Now is the time to bring them out. They will first evaluate the exterior cladding on your home. What do you have? Brick, wood siding, stucco, and asbestos are all fairly common on houses in this era. We’ve even seen houses in Iowa that are all concrete. Depending on what you have, insulation could be added from the exterior by either drilling holes in the cladding or removing some of the cladding to access the wall cavity. In the case of brick or possibly even stucco, this may be better done from the inside by either drilling holes in the plaster and patching or removing the base board and installing from there. The two best options for adding insulation in an existing wall are dense pack cellulose and open cell spray foam. Ease of installation and cost can be your guiding factors in which you decide to use.
- If you are planning on residing your house and will be taking off the existing wall cladding, insulation should be a part of that overall project. You will have the added benefit of being able to add a layer of high-density foam board to the exterior that will serve as a complete thermal break (you’ll even have some insulation where the studs are, not just in between). The foam board will also help eliminate some air leaks.
- If there is an option to use an infrared temperature camera as the insulation is being installed, do it. This will help the installer make sure they are getting good coverage in the wall cavities and identify areas that may get missed.
- A thorough insulation job with either the dense pack cellulose or the spray foam will do a lot to slow down the air leaks. There are still a couple areas to address. If your exterior walls sit on the floor system verses going straight through (a technique called balloon framing used in early wood frame houses) air could be leaking in. It’s kind of hard to get to, but if you have an opportunity to get behind the baseboard and caulk the connection of the floor and the bottom wall plate, do it. This may be totally impossible so don’t tear the place apart to get to it.
- You may still want to add the little foam gaskets behind the wall outlets and switch plates but you could wait to decide until after your blower door re-test.
Now to the basement: First a quick note, if you have water problems in the basement, they need to be corrected before any insulating is done.
- We’ll address the floor first – Don’t worry about insulating under the floor unless you have plans to remove it. If you are going to remove it for some other reason, be sure to include two inches of high-density foam board and an 8-10 mil poly (plastic) sheet under the slab. Be sure to tape and seal the seams and edges for radon. Done!
- Dirt floor crawl space – this needs to be addressed. A dirt floor will continuously add moisture to your house (a bad thing) and could be a source of radon gas (also a bad thing). You will probably have to clean up the space, remove broken bricks and junk, and level off the dirt. Add a layer of an 8-10 mil poly sheet to the floor and run it up the side walls a foot or so and seal it to the foundation walls using caulk and cleats. Seal all the seams and penetrations and now add two inches of high density foam board to the floor. Code may require you to cover the foam board with a non combustible material like concrete.
- Before we insulate the basement walls, caulk the joint between the floor and wall as a radon seal.
- The foundation walls including the walls in any crawl space should be insulated with a layer of 2 inch high density foam board. This can be attached to the wall with a few concrete anchors and washers. Just enough to hold it in place. Now you have a complete insulated thermal break wall.
- Next, attach wood furring strips to the face of the foam board with long concrete anchors to the foundation.
- Lastly, hang a layer of ½ inch moisture resistant gypsum board to cover the foam. Stand the sheets upright so the seams are on the furring strips. This has to do with protecting you from flammable material.
Now, if you have addressed your windows and exterior doors (covered in other areas) you are ready to have your HERS rater back to see how you did. During this next testing you need to have your rater run a check on how well your combustion appliances draft; water heater, furnace, fireplaces etc. Because you’ve done such a good job sealing up your home, they may need to introduce make up air to keep from back drafting. This is critical to your safety! Carbon monoxide will be introduced into your home if a combustion appliance is back drafting.
At this stage, it is important to consult with a certified HERS rater or an HVAC professional to design a ventilation system to provide good air quality. This may include additional exhaust fans or a heat recovery ventilator.
This may seem crazy that we worked so hard to seal up the house just to bring in outside combustion air and additional ventilation. The important thing is that you are now in control of how much and where that air comes in. Good Luck!
Now that you’ve finished this section, take some time to fill out this questionnaire to assess your home’s insulation. Keep it with the other questionnaires to build a resource you can reference when tackling projects at home.
Heating and Cooling
Most homes in Iowa between 1940 and 1975 would have had a forced air system installed. This is a system that heats and cools the air in the home and pushes it through a ductwork system to all the rooms in the house with a fan located in the furnace. In most homes the basement is the location of the heating equipment and the ductwork. If your house has central air conditioning there will also be a unit that sits outside, that‘s the compressor. The compressor probably has been replaced by now but it’s not unusual to find some really old (and inefficient) compressors still on the job.
The heating system burns fuel (mostly natural gas or propane). This is an actual fire or series of flames that heat an exchanger in the furnace that air is blown over to send the heat throughout the house. The air conditioner works much like your refrigerator. The compressor unit outside your house, which has a compressor (obviously) and a fan, pressurizes a coolant in piping. As the coolant is compressed it gets cold and gives off heat. The fan runs to remove the heat. The cold coolant in the piping is then pumped to a coil of pipes and fins located, usually, just above the furnace. The furnace fan then blows air over the cold coil sending the cooled air through the ductwork to the various rooms in the house.
What you see now is probably a new heating unit (furnace) and new central air unit. It may be hooked to some new ductwork but probably still uses the original stuff.
The ductwork system most commonly used will have a large metal supply air plenum coming off the furnace unit with 6” to 8” round pipes coming off the top or sides to feed air to the different rooms in the house. There will also be another plenum, usually about the same size but shorter, called the return air that brings air back to the furnace from the different rooms in the house. Instead of round pipe from the plenum, the spaces between the floor joists are used. A piece of sheet metal was usually nailed to the bottom of the joist to create the space. In some two story homes the ductwork can actually be in the attic. Make a note if you have ductwork in your attic.
There certainly were other systems used to heat and cool homes between 1940 and 1975. The furnace may have been all electric using a heating coil instead of a flame, much like your toaster. Or you may have a boiler that pumped hot water to radiators in each room.
Some of the earlier homes may not have had air-conditioning installed at all originally. By the time we reached the mid to late 60s most homes would have had central air-conditioning.
You will need to do a little checking to see and understand what you have.
There are a couple of questions to consider as you are looking at your current heating and cooling system. Before you even think about replacement units, consider safety first, especially if you’ve had headaches or flu like symptoms and if your house is not all electric, have a professional contractor check the back drafting throughout your house, especially if you have added any new fans in the bathroom, kitchen or elsewhere.
- How old are my heating and cooling systems? If your furnace or air conditioner is over 20 years old, you may be on borrowed time. Replacements are probably in the near future. Its not always the unit in the basement but its the exhaust pipe or pipes within an old chimney or hidden within the walls that may be failing which can be very dangerous. If you see holes in any exhaust pipes, please seek a professional contractor.
- Are my heating and cooling systems energy efficient? This may be kind of hard to determine. If you have done improvements on the building to make it tighter and more energy efficient, and you are dissatisfied with your energy bills, you should look at what a new unit would do for you. Your energy costs can be calculated (estimated) with a new unit so you can compare. A heating and cooling contractor can help with this. There is more useful information to follow regarding how to figure this out.
- Can I be comfortable in every room in my house no matter what the temperature is outside? It’s not uncommon to have rooms that just never get very warm or an upper level rooms that are hard to cool. This has more to do with your delivery system (the ductwork or piping) than the furnace or air conditioner.
That was the fun part, now for the not so fun but extremely important part – making sure the system is operating safely. Note – you cannot do this yourself; you have to have a professional inspect your system to make sure it’s operating as it should be. When we burn fuel inside our home (or anywhere for that matter) it gives off carbon monoxide. This is dangerous stuff and all of it needs to be vented to the outside. Your heating and cooling expert will check for proper combustion and venting to make sure your system is not letting any of this dangerous gas mix with the air you breathe inside your home. We can’t stress how important this is – it’s a matter of life or death. If your heating and cooling contractor is saying things about a cracked heat exchanger or back drafting you need to listen up and take immediate action.
It’s a good idea to have your system checked each fall before heating season to make sure it’s working properly. If you have central air-conditioning you should have a check done in the spring also just to make sure it’s working at its’ peak efficiency.
One thing you should have completed is the energy load on your home. What you want to know is how many BTU’s (British Thermal Units) of heat it takes to keep the inside of your home at 68 degrees when it’s 6 below zero outside, and how many BTU’s of cooling does it take to keep the inside of your home at 78 degrees when it’s 98 degrees outside. These temperatures are commonly used here in Iowa and you can adjust them to something more suitable to you but be careful, the idea here is to be able to properly size your equipment not oversize it. When we oversize the furnace and air conditioner it will become less efficient to operate. If we under size it we may not be comfortable in our home. Note: it’s pretty rare that equipment gets undersized by any heating and cooling contractor.
How do we go about getting this information you ask? It’s relatively simple; you ask your Heating and Cooling contractor for a ‘manual J’ calculation and if they look at you funny you may want to get a new contractor. A good one will ask for some information about your home and you will have most of it because you’ve already inspected and improved your insulation and windows. You also had a blower door test done so you know your air infiltration rate. Here’s what information will be needed:
- Square footage of each level of your home including the basement
- The ceiling heights of each level (we’re figuring out the volume of your home here)
- The square footage of the glass area on each side of the house labeled East, West, North and South and the U value of the windows.
- Square footage of exterior doors and what they are made of.
- How the exterior walls are built starting from the outside to the inside. Be sure to include the R-value of insulation in the walls as well as the finish and structural materials. Remember the basement walls; they will be different than the above grade framing.
- The R-value of the attic insulation and how the ceiling is built, i.e.: plaster on 2×6 ceiling joist spaced at 24 inches. (lines 3,4,5 and 6 above will help calculate the thermal resistance of your home)
- Lastly the air leakage figure. ACH50 (from your blower door test)
From this information the energy load in BTUs for both heating and cooling can be calculated. This is a constant figure and will not change unless you do something to the building envelope. This is also how you size the furnace and the air-conditioner to fit the loads on your home. You see now it becomes apparent why we do the insulation, windows, and air sealing before we put in the new furnace and AC. Our improvements to the house have affected the heating and cooling load; the better our improvements the lower the loads thus the smaller the equipment. LOOK, LOOK, were saving dollars not only on our energy bill but on the cost of installing the new equipment too!!!
There are some other tests that can be done on your heating and cooling system that will help you know how effectively your equipment is working.
One that you can do is measure the temperature in each room to get an idea of how even the heating and/or cooling is. Ideally you would check the heating system on a cold winter day and the cooling system on a hot summer day. Be sure to note the outside temperature along with your other readings.
You’re heating and cooling contractor or energy specialist can also check the airflow if you have a forced air system (the big blower fan in the furnace). The two areas to have them check are 1st, the airflow on each side of the furnace filter, and 2nd, the airflow at each register. This is important because restricted or poor airflow can greatly reduce the efficiency of your equipment and the comfort level in the house. We need to talk a little here about the air filter. Most systems will have a disposable filter like the type you buy at the big box store. Some of these are sold as super allergen dust busting mega great filters and they probably are. The thing is they could be screwing up your airflow in the ductwork so badly that your fan can hardly push the air through it. The best thing to do is use a cheap, fiberglass mesh filter and change it often (once a month or month and a half). There are filter systems that you can add to your ductwork system that are electronic or have large pleated filter material. You may want to consider a filter system like this especially if there is someone in the house with allergies. The important thing to remember is no matter what filter system you use there needs to be adequate airflow across the filter to provide the needed air to each room and keep the fan running at peak efficiency.
The super duper filters usually have a MERV rating. MERV 8 is good, MERV 10 better and MERV 13 or above is best. While the contractor is testing airflow, this would be a good time to try a couple different filters; all must maintain proper airflow from the furnace fan.
Once we are sure everything is working safely (our number one priority) our goal should be to have comfortable rooms (temperature wise) throughout your home at a reasonable expense. This may mean adjustments in the ductwork using your existing equipment or maybe replacing some outdated equipment with newer more efficient units. Or maybe everything is dandy for now and you can look at this when the furnace wears out later.
It can be very confusing to upgrade a heating and cooling system. Probably the biggest mistake that‘s made is assuming that a new furnace or air conditioner will solve all your problems. The distribution system (the way we are going to get the heat or cold to all the rooms in the house) is equally important and maybe even more so.
Heating and cooling improvements are not a do it yourself project and need to be done by a qualified heating and cooling contractor. Having said that, there are some steps to be taken that will help make sure you get a good system.
Since most heating and cooling systems in Iowa consist of a ductwork system connected to a forced air furnace with an air conditioner unit attached, we will proceed with this type of system in mind. If your heating and cooling system is different, there is still a good deal of useful information you can use so read on.
- Keeping in mind the proper order of things, you should have done your window, insulation and air sealing improvements first if possible.
- Have the load calculations figured for your house, preferably with required BTUs and cfm of air for each room, both heating and cooling.
- Have your temperatures of each room for both heating and cooling available.
- Test your ductwork system for airflow efficiency. This would be an opportunity to see how your filters affect your airflow. You may want to have a couple different ones around to try.
- Adjust your room registers to balance the airflow.
- If you feel there are problems in the air delivery, they should be addressed now. This can require some creative thinking by your heating and cooling contractor.
- Once you are satisfied the ductwork is capable of handling your comfort needs, then you can start looking at upgrading the furnace and AC units if you want.
Now let’s talk about the heating and cooling equipment.
- The first and probably only step is selecting your equipment. This is not an easy decision but we are here to help. Lets walk through some of the options.
|Central air and air sourced heat pumps||Furnaces – gas, fuel oil and propane||Boilers – gas, fuel oil and propane||GeoThermal closed loop||Mini split|
|Good HVAC||Cooling||13 SEER||N/A||N/A||14.1 EER||N/A|
|Heating||8.2 HSPF||90 AFUE||85 AFUE||3.3 COP||N/A|
|High efficiency HVAC||Cooling||14 SEER||N/A||N/A||15.5 EER||17.8 SEER|
|Heating||8.6 HSPF||92 AFUE||87 AFUE||3.6 COP||11.3 EER|
|Very high efficiency HVAC||Cooling||15 SEER||N/A||N/A||17 EER||20 SEER|
|Heating||9.0 HSPF||94 AFUE||90 AFUE||4.7 COP||11.8 EER|
Pros and Cons of each heating and cooling system:
Gas, propane or fuel oil forced air combustion system
Pro: quick temperature recovery, inexpensive equipment, can retro fit into most homes with a ductwork system
Con: combustion fuel source of Carbon Monoxide (CO), dirty, fuel price fluctuates
Central air conditioning with a frame coil and exterior compressor
Pro: can be fitted into existing forced air heating system (uses the same ductwork), whole house coverage, quick temperature recovery, contractor friendly since this is the most prevalent system
Con: susceptible to dirty environments (leaves, dirt, sticks) so requires occasional maintenance
Boiler radiant heat (combustion fuel boiler with piping to radiators)
Pro: quiet ‘soft’ heat
Con: cannot accommodate a cooling system, slow response times
Electric resistance heat-radiant (base board heaters, radiant ceiling panels, heated floor.)
Pro: in the case of baseboard heating, it’s cheap and easy to install & you can put controls on each unit for easy zoning, simple design with not a lot of complicated parts, electricity can be produced in a number of ways, and it will almost certainly be a fuel source we will have years from now
Con: electric heat is usually expensive, cannot accommodate a cooling system, can be cost effective with an all electric rate (see your utility provider), also suitable for air source and mini split heat pump back up
Ground sourced heat pump (geo-thermal) heating and cooling
Pro: electricity can be produced in a number of ways and will almost certainly be a fuel source we will have years from now, AC and Heating come from the same unit, equipment is inside & out of the elements, equipment is the highest efficiency of all possible units, cost effective with rebates and tax incentives, can also produce hot water
Con: can have slow recovery
Mini split heating and cooling
Pro: very efficient, can heat and cool, fairly easy to install, can be used in small spaces such as additions as an additional heating and cooling source, easily used for zoning, can be cost effective, good for remodeling since no ductwork is needed
Con: may need several units to do an entire house, some installations look like window AC units (visually more dominate)
These are a few of the most common heating and cooling systems offered here in Iowa. There are others but be wary unless you have a trusted energy specialist working with you to evaluate the system and how it will work in your particular situation. There is a lot of weird stuff out there and not all of it is worth your time, trouble and money.
Now that you’ve finished this section, take some time to fill out this questionnaire to assess your home’s heating and cooling. Keep it with the other questionnaires to build a resource you can reference when tackling projects at home.