I own a beautiful old home that only has a subfloor beneath the flooring, and this has been causing major temperature issues for us. With 14ft ceilings, we often find ourselves freezing or sweating throughout the year due to this situation. Recently, I discovered some cracks and openings in our floor that expose the dirt crawlspace, which made me realize the extent of the problem. I'm looking for ways to effectively insulate from underneath. Is it feasible to use insulation sheets beneath the floorboards and then cover them with plywood? My concern is that spills could lead to mold issues with the insulation. Any suggestions on how to tackle these high utility bills while ensuring a comfortable home would be greatly appreciated!
1 Answer
In similar homes around here, it's common to lack floor insulation in crawl spaces. A good approach is to put down thin plywood (around 3/8") across the entire area, sealing all the gaps with caulk. After that, you can add your chosen flooring—I'd recommend Luxury Vinyl Plank (LVP) for an upgrade. In summer, make sure to vent your crawlspace, and then seal it up in the winter. Also, if you have ducts running through there, don’t forget to seal those joints and points where they come through the floor to avoid air leaks.
The floor has its own charm despite the wear. We're hoping to keep it visible as the top layer, but we might not have another option.