Cold Closet Bump Out
I have a 1969 ranch with a bump out for two adjacent bedroom closets. During the midwest winters, this closet is frigid, which causes the bedrooms to run 5 degrees cooler than the rest of the house.
The bump out extends to the exterior grade – there is no gap between the structure and the ground. From what I can tell, the brick veneer extends to concrete block in the ground with no gap at the joint.
When I fished an inspection camera into a hole, I saw building material under the floor, including what looked like concrete block. I’ve added some spray foam insulation through some holes drilled in the flow hoping to plug any gaps between the concrete block and the outside air, but to no real avail.
The basement is finished so I don’t have good access to the underside of this.
Any advice for how to proceed? Dense pack cellulose into the floor? Remove the closet floor entirely and get a better view?
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Replies
I think more investigation is needed before settling on a solution. Removing some of the subfloor does sound like the easiest way to do that. Are you sure the problem is the floor though? A thermal camera or infrared thermometer might provide some insights.
I had the attic air sealed and I know they sealed above the closet.
My infrared thermometer shows decreasing temperature as I move down the wall. I have opened a 4” section of the subfloor and feel cold drafting.
Is my only option to fully open the floor or could foam be injected through a small access port or the exterior brick veneer?
The spray foamers have wands for getting into tight spaces but I don't know how consistent or complete the coverage would be if they don't have a clear view of the surface being sprayed. If the finish flooring can be easily removed without damage, then cutting a bigger hole in the floor seems like the best approach. From the exterior, you'd have to chisel out an entire brick, probably in a few locations to get access to the entire space.
Could be leaky rim joist details, which may be especially bad (in terms of leakiness) with an added-on bump-out type of structure like this. Unfortunately, you'll probably need to take some things apart to be able to correct this. Taking out the interior floor may be the easiest way to go here.
I'd also try to get some air circulation through the closet if possible. I have a closet on my second floor that is "stolen" from the attic (i.e. some of the attic was converted to closet space), and I'm in the process of adding an air return in there to help with the temperatures. My closet is well insulated and air sealed, but with little air movement to the rest of the house, hot/cold tends to get "concentrated" in the closet.
Bill