Is my basement worth insulating?

[joefrompa]

Hi all,

mid 1970s 2-story colonial. Basement is a poured concrete foundation and in many places has fiberglass batts stuck to the concrete with a vapor barrier facing the inside space.

When it's mid-winter and 25 degrees outside and I'm only running the wood burning stove (which is on the first floor), the basement stays a consistent ~65 degrees. In truth, it never get uncomfortably cold down there. It's ~35% humidity in the winter and a dehumidifier runs alot during the summer keeping it at 45%

I have access to about 15% of the un-finished basement walls which remain uninsulated. I'm considering putting up something like 1-1.5" thick XPS foam board on those walls but I have no idea if that's worth it: it's only what I have access to, the basement seems to hold itself to a good temperature in the winter and it's not like I'm trying to heat it moreso, and I don't even know if it'll be worth the effort.

The attic is R-38 between blown in cellulose and then batts laid down perpendicular. The walls of the house are r11 or r13. The house is going to be re-sided this summer at which time I'm going to have it foamboarded, tyvek'd, taped, & sealed....it MAY actually become too tight for airsealing but I think it'll just get close to that. And I'm going to be tearing out the garage drywall, attaching some thickening strips to the drywall, and re-insulating the walls with thicker batts and re-sealing it.

I'm just trying to figure out my last few places to improve the heat retention of my home

So - insulate those exposed walls of my basement or leave it be and save my money and time?

Joe

 

[Adios Pantalones]

Do you spend time down there?

 

[joefrompa]

It's a finished basement. We don't spend much time down there now - but I can see doing it in a few years.

 

[velvetfoot]

You might not have to run the dehumidifier as much.

 

[begreen]

I'm curious what the temp in that uninsulated area would be if it were partitioned off? Thinking cool storage/root cellar here, which we would love to have.

 

[joefrompa]

Hard to say - the uninsulated area currently sits in with the furnace/oil tank and water heater. I'm sure that's skewing it, but it all feels just stable to me.

The top ~8" of the foundation is above grade though and that's probably where I'll look carefully to see if I can do something. On one side of the house I forgot to turn off the hose and that pipe burst a seam when I turned it on at the beginning of spring.

 

[lukem]

I'm curious what the temp in that uninsulated area would be if it were partitioned off? Thinking cool storage/root cellar here, which we would love to have.

Not to get too far off topic....but I have an uninsulated area in my basement where I keep my soon to be burned wood (about a month's worth at a time). It only has a 5' ceiling so it's not really basement...just a room off the basement. It stays in the low-mid 50's in the summer and gets down in the 40's in the winter...and is always dry (now that I patched up the outside access hole). Concrete floor, walls, and ceiling. Works great for storing 'taters from the garden. I should harvest about 100-150lbs of red and another 100lbs of white this year.

 

[begreen]

OK, that won't work for a root cellar I guess. You might want to check on code to see whether the XPS insulation can be used near a furnace, especially if it is within a few feet of it.