With the Ontario Government at it again raising prices on Natural gas and the ever increasing cost of electricity in Ontario it is more important then ever to have a properly insulated home.
When you are planning to have a new custom home built you should be setting a side money's in your budget for upgraded insulation. Why you ask?
There is no easier way to save money on heating and cooling then upping the insulation R value in a home that you are having custom built.
If your contractor is good at what he does he will make the recommendation of updating your insulation in your new home well before you ask, usually it comes when the house is being put together or (framed).
You can ask your contractor during the estimating process for insulation options so that you will know the costs, but you do have until the insulation is installed to do certain updates to the building insulation envelope.
The building code in Ontario has changed in the last 5 years and with that the standard for upping the R-value (insulation value) in your walls has also increased. But that doesn't mean that the new minimum code is the best that you can do, there are actually many options that help make your home perform better at heating and cooling;
Spray foam: Spray foam far exceeds any other insulation type in the way that it gives more R value per inch then any other insulation product. This allows you to up your R-value without altering the wall cavities of the home. It also expands when it is installed filling in all the small crevices that allow air leakage. Once it has dried and hardened it will not slip or move no matter what the circumstances. This way of insulating stops drafts and air leakage a lot better then conventional batted insulation. You don't have to spray foam everything in the house, spray foam can be used with almost any other combination of insulation to help seal your home. This flexibility allows you to fit a small amount of spray foam into your budget or a lot of spray foam if you have a larger budget.
ICF; ICF or (Insulated Concrete Forms) are not just an insulation they are a completely different way to build the exterior walls of your home. ICF is basically a giant lego block made out of foam and plastic webbing. the foam is on the outside of the wall and also on the inside of the wall. Concrete is poured down the middle of the block foam wall creating a concrete wall that is wrapped in foam insulation. This gives you the R-value you need for the building code, but it also gives you something a lot more. It gives you what is called thermal mass. Thermal mass is what makes in-floor heating work so well, once the concrete mass in the walls is warmed (or cooled) by your furnace then it takes a long time to cool down. It will actually radiate heat and because it's insulated on both sides it doesn't take much to warm it up. ICF walls do not suffer from "wind wash". Wind wash is when you have a high windchill outside and the wall cools down, this usually makes it hard for the furnace in the house to keep the place at temperature. ICF walls because they are insulated on both sides and are concrete at the core do not allow the windchill to penetrate the wall at all. Thus windchill has little to no affect on the inside temperature of your home.
Sheet Foam: Sheet foam is just what it sounds like, it is sheets of foam that you apply to the walls of home. This is usually done to the outside of the home, but can be done as a retrofit to the inside of your home if you have brick or stone that cannot be removed to allow for the added insulation. The sheets of foam cover the studs of the walls and thus helps stop the heat loss that happens through the studs on wood framed homes. Sheet foam also helps to stone wind wash.
Double Prairie Walls: This is a type of construction where you actually build two exterior walls, one in front of the other.The first wall is built conventionally as a 2x6 wall, insulated and vapor barriered. The only difference, you do not install any electrical or plumbing in the wall. A couple inches in front of that wall you build a second wall made out of 2x4's, this wall is also insulated but not vapor barriered. All the plumbing and electrical go in this wall. This helps create an exterior wall with little to no penetrations in it and also creates more insulation value as you have a second wall with insulation in it. It also helps to stop wind wash as there is a heated cavity space between the walls to allow the cold air to warm up before it enters the home.
There are many other ways to help seal up your home and also many other options to insulate your home, talk to your contractor as your budget will play a bigger part in how you insulate your home then what you want your insulation to be.
Rob Abbott
Village Builders Inc.
Hello. Double wall construction has interested me for some time. With a double 2x4 construction the batt (Roxul R14) would give an R28 with decent wind wash and thermal bridging attributes.
ReplyDeleteBeing in Southern Ontario near Lake Erie and the double walls connected top and bottom with 5/8" plywood, what is with the 2x6 outer wall?
Thank you in advance for any and all teachings.
Regards,
Frank.
There's a couple of reasons why you would still have a 2x6 wall on the outer part of the house, one is it actually gives you a far higher R value, it also allows you to put things in the 2x6 wall and still have insulation in it. a pair of 2x4 walls means that everything has to go into the inside 2x4 wall, this limits the space and the amount of things that can go in the wall. The third reason why is that a lot of engineering for house building is designed for 2x6 walls to side and bear on the rim joist on the outside of the house overtop of the rim joist. When you go to a 2x4 wall you start having to re-engineer things and change the blocking. So for the 1.5 inches that you save on the 2x4 walls it could end up costing you more money and have less R value.
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