Insulation is a critical component to making your home more energy efficient. We are going to look at the subject of insulation in some unique ways and not just the usual line about more is better.
First off, we need to put insulation in perspective. Air leaks through your ceiling can virtually nullify so many of the positive aspects of your insulation layer. Loose fill insulation, and batts do not stop the leakage of air. bottom line. You need to address air leakage issues first. [stextbox id=”info” caption=”Spray Foam Insulation Stops Air Leaks ” bwidth=”2″] Now if you have spray foam insulation in your home you are not reading this page. But if you don’t, you might be evaluating whether spray foam insulation makes sense for you. Spray foam is a great air sealing option but such a choice needs to be made around key criteria-depending on the unique aspects of your home. There are key questions you need answered about your home- to determine whther spray foam is the best fitting solution for you. It is probably better to hear a broad discussion rather than the point of view of one sale-motivated salesperson. Not all sales people are this way. The best sales people- the ones watching out for you- will want you to have all key information, so that you have a broad perspective to help you decide what is best for you. We discuss the strengths and weaknesses of spray foam in your North Texas home here. [/stextbox]
How much insulation does your home have? How much makes sense for you?
We will eventually get around to evaluating what professional advice and consultation you need- but first you need perspective because you have to fend off a lot of greenwash and BS related to energy saving products. You always have to beware the tendency of “experts” to see every problem through their own tool box.
We want to help you here, by making sure you have some fundamental understanding of building science. The basic concept is to know why things happen and treat issues at the level of he actual problem and not treat the symptom.
Everybody just knows that more insulation right now is great.. right? No not right. We already mentioned air leaks. You solve air leaks in the attic by moving batts and loose fill and cleaning up the dust for sound bonding of air sealing materials. More insulation in place- the attic tip topped with loose fill has to be moved to seal leaks and so extra insulation is just more work.
And if you do not understand where your insulation pattern is problematical- if you do not identify and solve your insulation short circuits- well the result on your average R value really suffers. We delve in their shortly but first we need perspective.
How much insulation is suggested in North Texas?
We are in climate zone 3 and the 2009 International Energy Conservation Code- adopted in Texas a couple of years ago, says R-30 in the ceiling and R-13 in wood framed walls.
You might wonder why only R-30 in the ceiling. This relates to North Texas being a cooling dominated climate area where we use more energy to keep cool than we use to keep warm. But our extreme days do not create the huge differential temperatures between ambient air and our cozy interiors that our neighbors in the far north- even up in Amarillo experience.
This is a minimum suggested but there are diminishing returns. We have our own key issues in North Texas where we can maximize our returns- air leaks have a serious impact here, and leaking ducts- poorly insulated supply ducts in unconditioned attics can have much more impact on us than topping out insulation over R-30.
Your big gain for insulation and energy saving revolves around your ceiling and attic, anyway,
for three powerful reasons. Most attics have myriad pathways for air leakage- we details those here, but the stack effect, the pressure created by differential air densities is the driving force- pushing your heating air out in the heating season and letting the hot North Texas summer air sink in in the summer. The Stack effect and all the natural and unnatural forces that empower air leaks are described here.[stextbox id=”info” caption=”I seem to be repeating myself about air leaks being bad” bwidth=”2″]They are. Air leaks have many negative impacts on your home … [/stextbox]
Third, your attic is a complex place. You will notice, when you get up there- you would not be reading this unless you had some concern about insulation- that there are areas of the attic where insulation is missing- insulation is ill-fitting around obstructions and you can likely discover insulation issues around construction details- like light bys, around eyeball lights, dropped ceilings… all these issues leave you with uneven insulation and uneven resistance to energy transfer out of your home.
Uneven insulation impacts your overall R value significantly more than you might think. It does not average out. The low insulation areas are much like a short circuit allowing precious conditioned air to heat up or cool off without adequate resistance to heat flow. We discuss this short circuit principle here.
And, on the subject of poorly insulated components in your ceiling and attic, nothing is a bigger energy waster than your attic access stairs. We cover the sordid details and solutions here.
There are all kinds of issues in the attic. That is why we suggest an adventure into the attic to check on all kinds of potential energy wasters there including insulation.
Good news. Attics and ceilings are relatively easy to work in…
as compared to crawl spaces or actually having to cut into walls. Even though the attic can be a mess of complexity; you can visit up there, and it is accessible to making useful changes without impacting finished walls.
Retrofitting walls becomes a complex calculation best left to careful analysis and use of specialized software by a certified professional energy auditor. You need to keep track of your dew point in your walls, and understand how the wall deals with moisture migration. Yes, this is not an issue to take lightly.
Beware of Kind Strangers who Offer Great Deals on Insulation
You can find a variety of contractors that will be happy to top off your ceiling insulation for you as part of a roofing project, or part of some work on your HVAC system- This has become a nice little profit center for contractors to upsell like McDonalds and french fries. You want to avoid these offers.
I hope we have given you a sense of the issues you need to evaluate before you add “3 inches of insulation with that” Now there are conscientious companies that are starting to deal in building science and home performance and they might make offers to you. [stextbox id=”info” caption=”What is home performance?” bwidth=”2″]New terms get coined that mean little to the people that home performance contractors want to influence- home owners. Home performance is a critical differentiating term. We discuss the term here. Here is a good example that will shed light. For decades, an HVAC contractor would prescribe a dehumidifier for a customer complaining of mugginess in their house in summer. Now an HVAC contractor that understands and operates from the idea of home performance, would know the moisture issue is related to air leakage rates and want his or her customer to undertake testing and air sealing to solve the problem with mugginess. The home performance contractor is looking for root causes- not finding superficial ways to treat the symptoms of the root issues. [/stextbox] Evaluate these from what we say here, and what you read elsewhere. We also have people who believe in home performance in name only… just more ways to introduce green wash… you will hear and understand the difference.
Evaluating insulation and adding insulation is serious business. The decision should not be left to the happy camper with an insulation blower and bags of loose fill… You need solid information and accurate analysis. Like what you can get from a HERS certified energy auditor or a BPI building analyst. Or from an HVAC contractor well versed in home performance. You need a pro with perspective.
Does it make sense for you to invest in more insulation? There are a couple key questions here to answer.
How Much Insulation Does Your Home have now?
Are your ceiling joists visible? This is good news and bad news. The bad news first. You need more insulation. Ceiling joists are only 7.5″ deep if your ceiling joists are 2X8s but you will be measuring that not trusting my prescient powers. The good news is that you can get the air leaks sealed up more easily- save a few bucks- by not having to move so much insulation out of the way.
Here are a couple key pictures. You can decide which is more representative of your home.
If you see nothing but a sea of insulation- no joists and it looks level and even everywhere, and you see ventilation baffles protecting your soffit ventilation… you insulation is fine. Of course, you have a long list of other items to check in your attic exploration list.
Lets revisit the issue of the lay of the insulation some more. This is a critical issue. The least insulated portions of your attic have the predominant effect on how well your attic is insulated.
First is… lets look at the effect of lumpy uneven insulation in your attic. Lots of North Texas homes have cut up roofing with many facets. These all add considerable support structure between ceiling rafters and roof structure. Batts don’t fit well in irregular spaces.
Or maybe someone has done work in your attic?
Has something messed up the even lie of the insulation. You should have soffit vent baffle to maintain attic ventilation and so the insulation is even in depth right out to the eave edges of the roof deck. We again mention the short circuit principle These areas of poor insulation placement have a disproportionate impact on the overall insulative effect in your attic.
The attic is a complex area to discern. Dropped ceiling and light bays can create issues. W already talked about the attic hatch. These extraneous issues are huge energy and money wasters.
Chimneys and plumbing runs into the attic can fit through a baffling array of openings called chases. These are intended as opening to facilitate the placement of chimneys and plumbing but often they don’t get air sealed and not properly insulated. Insulating items like a stainless steel flue or eyeball lights with light housing that cannot touch insulation are special issues to be solved with retrofit covers which can be air sealed and chimneys by special products designed for such specialized use.[add images of chases here]
Do you have insulation in your walls?
How much insulation do you have in your walls?
Walls can be tricky to figure out unless you are very short. [lamejoke alert] You can take off an outlet cover and look in with a flashlight. No probing allowed with metal screwdrivers. It probably makes sense to turn off the power, but it is 110v and all you can get is a nasty jolt and only then if you are foolhardy. And you are not foolhardy or you would not be reading this. Try out a flashlight and a good working set of eyeballs and see what is there.
There is just a lot you are not going to see in your wall beyond seeing batts or packed celulose. Jump up and down for joy in you find packed cellulose. But you won’t that is a recent design change and you are not reading this if you have recently bought you new green home.
Batts are problematical. Cutting around fireblocking and cripple studs can be done with precision but this does not happen often. Gaps in insulation have a huge impact on your overall insulation system.
To really see inside your walls and what kind of insulation issues you might have, you need a professional with infra-red technology. They can use thermography to take a heat signature of your home and spot the problem areas.
These kinds of problems are notorious in bonus rooms or add-ons. But homes can have cold walls right out in the middle of the wall.
What happened here?
Several possibilities. An insulation installer did a crappy job OR someone torn into the insulation to retrofit a wire or a pipe, OR water has penetrated through the exterior and well the insulation in the wall. Itpays to find out. You can stop a serious structural issue and you can be warmer and more comfortable. We discuss exterior issues with leaks here.
Cold spots in walls are not magical and those same spots become hot spots in summer.
There are lots of options with walls. You just need some professional help to appraise where you are, and what your options are. Wet walls are an issue that needs addressing as the damage only grows. Entering the wall structure-changing the cladding to insulate walls does not have a high a return on investment as the ceiling but you might be in the mood for new windows too, or a new look and the exterior walls can become a place to add insulation and a more effective waterproofing layer… Window replacement is an often misunderstood issue- much purposely misleading info is proffered to you…
What about insulation in the crawl space?
Crawlspaces are a whole other animal and they need to be evaluated on how big a moisture issue it is causing you. All kinds of nasty things start with a damp crawlspace. Critter graveyard- water bug invasion route- a lot of your indoor air wafts in through the crawlspace. Damp crawl spaces are the realm of mold and mildew, North Texas is a humid place hospitable to the dark forces accumulating in yuur crawlspace. We deal with crawlspaces here. LINK
Has Your Home Ever been Remodeled?
Remodeling can mess stuff up. Or remodeling can make your home more energy efficient. It depends on the purpose of the remodel and often the purpose of the remodel is for cosmetic issues and for new layouts and the fundamentals can be short changed. Stuff gets covered up, patched onto, and cobbered together. We discuss the pitfalls of a remodeling here. LINK
What is our next step here ?
Evaluating the upgrading of insulation in walls and crawl spaces and ceilings can be about more than just wanting to save money. if you can impact aa air leakage issue or a thermal bridging issue,-there can be multiple payoffs beside the return on investment.
The ultimate answer is an energy audit
A qualified home energy auditor will include an insulation check as a routine part of an energy audit. An energy audit of your house will identify the amount of insulation you have and need, and provide you the perspectvie you need to make well informed choices.
Any comments, questions or complaints… just add them below.