Cold floors are no fun. No matter how warm and cozy you manage to make the rest of your house, there’s almost always that one room where you have to put on extra socks and a pair of slippers just to make it across the room without suffering frostbite. And unless you have a disorder of some sort, chances are your perpetually cold feet are due to the ice-like consistency of your floor.
Before you spend a lot of time and money on heating solutions elsewhere in your house, you should first consider your basement or crawlspace. Cold floors are most common when the space below them is unheated. Even with insulation shoved into the gaps between joists, if your basement is essentially a cube of ice-cold air it’s going to bring the temperature of the floor above it down several degrees.
Sure, you can wear slippers or put down carpets, but if you don’t address the root cause of your cold floors, you’ll never be truly comfortable in the winter. If the floor that is turning your feet into blocks of ice is situated over a basement or crawl space, consider installing a thermal break.
How a thermal break can fix cold floors
A thermal break is a product or material that reduces the conduction of heat between one material to another. In your basement or crawl space, for example, concrete or dirt floors are pretty porous, and let cold and moisture just pass through. That turns your basement or crawl space into a walk-in freezer, and that cold is then transferred to the walls and the ceiling—which is also the subfloor of the room above.
A thermal break installed over that freezing basement floor will create a floating barrier that’s not part of the floor itself. This creates a small air gap that keeps the cold from the floor from migrating upwards. This can increase the temperature of a basement or crawl space by several degrees.
You can DIY a thermal break in basements or crawlspaces using what’s known as a subfloor membrane panel, made from oriented strand board (OSB). Wood acts as an excellent thermal break, but will rot in short order from contact with a damp basement floor, so the waterproof membrane on the underside is essential. These panels will also be raised by pegs on the membrane side to create the necessary air gap. Laying them down involves cleaning and prepping your floor, cutting the panels to size, and snapping the panels into place using tongue-and-groove connectors. There’s some work involved leveling and stabilizing the floating subfloor, but it’s not particularly difficult to do, especially if you’ve ever laid down any sort of tongue-and-groove floating floor.
Companies also make tile systems that work essentially the same way, but without the rot-prone wood. These systems are proprietary and more expensive, but can be longer-lasting.
Once the thermal break is installed below your living space, the air gap will break the connection between the cold basement floor and the rest of the space, reducing the amount of cold and damp that gets transferred to your floor above. This won’t make your unheated basement a tropical paradise, but it will be warmer, and the floors above it will be noticeably more comfortable.