top of page
  • Writer's picturePENTA TEAM

How to Keep Your Basement Warm and Dry This Winter

Want to keep your basement warm and dry during the winter months? Or worried that frost, mold or moisture may be a problem in your basement? The answer is to use an air impermeable insulation—such as spray foam—when you insulate your basement.

Best Way to Insulate a Winnipeg Basement?

A basement doesn’t have to be a mouldy, wet, unhealthy space, but right from the start they have a lot working against them.

Hint - Spray Foam!

Basements are by nature subject to a lot of moisture. By design they are located in a hole in the ground (duh, state the obvious) and surrounded by earth that typically is very wet and never dries out. When they are initially poured the concrete contains thousands of gallons of water that takes a very long time to escape and dry out. The area below grade can only dry to the interior of the house. The area above ground freezes in the winter which makes for a perfect surface for condensation and frost to accumulate.

Poorly air sealed walls allow warm interior air to move behind the wall where it can come into contact with the very cold concrete and form liquid water or frost. Come springtime, this frost melts, the water runs down the wall and onto the floor leading us to think that our basements are leaking. The water and moisture that you don’t see provides the perfect breeding ground for mould and mildew. Homebuilders are fully aware that this happens as they get deluged (pardon the pun) with calls from their clients who think their basements are leaking. They call this phenomenon “meltdown” (fitting?) and explain to their customers who’ve spent several hundred thousand dollars on their dream homes that this is a normal process and that their basements are not in fact leaking. “Just wait a few days and you will see it will stop.” Hardly what most new homeowners want to hear?

By code, Builders are required to put a vapour barrier on the basement walls. This vapour barrier actually becomes a ‘drying retarder,’ hindering the drying of the wall which contributes to the aforementioned breeding ground.

What’s a person to do?

Conventional fiberglass and poly air/vapour barriers are very difficult to properly install in basements. They require perfect vapour and air barrier installations and this is just not achieved in 98% of the installations. Any newly built home insulated in this way WILL have moisture behind the wall, especially in winter. We get numerous calls from Homeowners who have started to develop the basement in their new home only to discover frost, black mould and wet wood once they peel the poly back. Ever wonder why Builders use white poly in basements but clear poly in all the other walls? Listen up!

The answer is to use an air impermeable insulation when you insulate your basement. This means some form of foam insulation. Ok it doesn’t have to be spray foam. You can attach Styrofoam or other form of foam plastic insulation. And remember, it’s important to make sure that warm interior air can’t come into contact with the cold concrete. That means taping and air sealing all the seams, but that is a lot of work. Think about making the rim joist area around the floor joists airtight!

Actually the best way to insulate a basement is from the outside with foam; spray foam or rigid board but that’s a story for another blog post.

Spray foam applied to the interior concrete (or wood if a wood basement) does an amazing job. It performs several functions in one product. It provides an excellent insulation. It air seals which eliminates the possibility of frost. 2 lb closed cell foam actually is waterproof, so if you do have a leak in the foundation it will help to keep the water from coming into the basement. It actually has drying potential, which will allow the moisture in a new concrete foundation to dissipate harmlessly into the interior of the home without causing mold or mildew.

So why don’t home builders install this in all their new homes? Of course, there is a catch. It’s more money. But who wouldn’t spend a few extra dollars to know that their house is going to be free of moisture problems. Well there are a couple of reasons. Many homeowners just don’t know about the potential pitfalls. Sales staff isn’t necessarily going to bring it to their attention when they’re trying to close the sale. Upgrades are often not even discussed until after the sale is finalized. At that point it’s discussed at the same time as flooring, cabinet, countertop, plumbing fixture and other “sexy” upgrades. Many, if not most buyers look at cosmetic upgrades first.

The sad thing is that many of our clients say “if only I had been offered the option at the time it could have added it onto our mortgage.” True, but there are ways we can help finance upgrades. That still doesn’t take away the sting that these homeowners are paying again for basement insulation after paying for it only a year or two previously in the cost of the house.

For a great visual explanation of what goes on in your basement, check out this excellent video from the NDSU U of Minnesota Cold Climate Housing Program.

Choose your insulation wisely, you can always upgrade the carpet or counters when they wear out. Your insulation will never wear out. At least not if you choose spray foam the first time. Contact us today to get a free quote!

367 views0 comments


bottom of page