Should I remove batting on basement ceiling after insulating basement
bevett
| Posted in General Questions on
Hi: I am about to insulate the mechanical room in my basement to use as a workshop. I’m putting Dricore and plywood on the floor, and RMAX and drywall on the walls, sealing the sill with foam. There is no heat in the basement, besides a pellet stove in an adjoining already finished room. Currently there is batting insulation across the ceiling, obviously to separate it from the conditioned house above. Once I’ve insulated the basement, should I remove the batting? It’s still going to be cool down there, with no direct heating. Will radiant heat from upstairs make it warmer, or will it make the upstairs colder? Or both? Or neither?
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Replies
My guess is the basement was almost the same temp as upstairs. That being the case the insulation was doing nothing thermally. After you upgrade the wall insulate the ceiling insulation will still be doing almost nothing thermally but it may absorbed some of the sound energy and keep it out of the upstairs so I say leave it in place.
Consider leaving the concrete floor as is. Energy losses are pretty low over all as you are getting free cooling in the summer. Most basement need all the head room they can get no point in rising the floor an inch or more.
If you are talking about sealing the mud sills on top of the basement walls with foam I like that idea. I see no reason to foam the sill board on the basement floor.
Did you read this article about basement walls?
https://www.greenbuildingadvisor.com/article/three-ways-to-insulate-a-basement-wall
Walta
I disagree that energy losses from the basement floor are low based on my experience living in a heating dominated climate. After I improved the basement floor and window insulation the basement became the warmest place in the house and I started closing the supply registers to the basement. There is enough waste heat from the gas furnace now to heat the basement without any supply registers.
A simple way to insulate the basement floor is to put down EVA foam tiles that you can buy from home depot, etc. 1/2 inch height only, don't do a full inch- that more easily can have impressions left. If you want the free cooling in the summer then to the extent you have an open unused floor it is easy enough to pull up the tiles and put them back down in winter. The payback period on this might still be many years, so whether it is right for you depends on your energy costs, climate, and comfort issues.
If you live in a heating dominated climate definitely keep the batting in if you don't have basement floor insulation or have super leaky windows and leaky rim joists, etc. In a cooling dominated climate it could make sense to remove them. Either way I would take the conservative approach of keeping them in for a year after your changes you are doing now to see how the basement feels during the hottest and coldest times of year compared to the house and then decide.