Need some Opinions!! Insulate the Basement Ceiling??

[precaud]

How about cutting holes and blowing in cellulose? It would take at least two holes for each row of joists. Unless you completely fill it, this wouldn't put the insulation against the floor (most desirable). But you could prep the whole ceiling before renting the machine. Just an idea.

 

[Gooserider]

How about cutting holes and blowing in cellulose? It would take at least two holes for each row of joists. Unless you completely fill it, this wouldn't put the insulation against the floor (most desirable). But you could prep the whole ceiling before renting the machine. Just an idea.

That would probably work, but it's not what I'm after... I don't see a real need to insulate the basement ceiling - I consider the basement as part of the living space, just not an area that has to be kept as warm. I'm more after draft sealing the foundation / house wall joint. That was why I was wondering about just putting a shot of foam into each bay trying to shoot it into the sill cavity as much as I can - it wouldn't be optimal, but I'm just trying to figure a way to draft stop without having to rip into the sheetrock visibly.

Gooserider

 

[Rhone]

Goose, in that case do the next best thing, caulk the area on the the exterior of your house where your foundation meets up with the siding. I don't recommend expanding foam on the exterior, in sunlight (and even full shade given enough time) the foam turns flourescent orange and looks like your house is being attacked by a strange orange fungus. After I did it, I ended up going around with a razor the next year and removed it. I recommend silicone when it gets warmer, be careful to just seal the joint between the foundation and the wood, really small bead and it helps prevent bugs as well. Any holes in vinyl siding should be left open they're drainage holes, and don't seal any gaps you find in any of the trim of the windows on the bottom, they're usually there to allow any water that happen to get behind the trim the ability to drain.

 

[jqgs214]

Ok, so I have the leakiest basement ever. 8 cans of expanding foam and I may need to use one more. GOt all the drafts buttoned up. Waiting for one more real cold night to make sure. l also put some left over fiberglass batting in the sill area and pockets. I cut paper backed r19x 16" length wise so it was 8" wide and that fit perfects on my sill (2x10 minus the 2x6 sill plate) Will let you guys know how well this does. So far the most I've seen is maybe and increase of about one degree at my t-stat but I dont feel as many "cold Spots" as I walk around. Going to take some temp readings again own there to see if it warmed the basement any.

 

[begreen]

Were the original temps taken on a windy or calm day. There might be only a few degrees difference on a calm day, but on a windy cold day, there should be a significant change.

 

[jqgs214]

was not calm but not very windy. Was cold for here, around 17* Outside. I'm noticing about a 1* change in living space temps, didnt measure the basement yet. I know its difficult to gauge the temp diffs in the living space but I seem to have some gain so far.

 

[homebrewz]

Hey, the basement thread is bumped up again! This has been a very informative thread.

I've been sealing up the casement windows, and will tackle the sill plate soon. I'm using 2" foam board. For maximum R-value benefit, should I be leaving a 1" or so airspace in between the sill plate and the foam board?

 

[elkimmeg]

Wxman glad your are making improvements and seeing them

Home I would forget the air space and double up the rigdid insularion board to achieve a higher r value then caulk the seams in

 

[jqgs214]

yeah, i'm going to put rigid over fiberglass bats I put in and then caulk it to get a good seal. Going to hang the rigid so it goes down below grade.

 

[carg3]

The sill plate is a piece of wood, usually a 2x6 that sits on top of your cinder block wall. In most cases, 8 or ten inch blocks are used. The remaining few inches are open spaces, since the opening in the blocks are not
poured solid except where bolts are inserted, every four or so feet. (They hold your sill plate down.) You need to seal those holes. I don't recommend stuffing them with insulation. It becomes damp, and the R-value is lost. A blanket of insulation, available in different widths and wrapped in a plastic bag, staples to the inside edge of your sill plate. At the bottom, you need to attach a fir strip of wood, and staple the blanket to it. In new construction, code requires this blanket be as low as frost level.....they're calling that four feet below grade here in upstate NY. It would be less where you are. This is just one suggestion, but the blanket would cover the sill problem as well as help the walls.

 

[jqgs214]

Little late for taht but I have lots of electrical wites stapled to the sill plate so would have been a ton of work to move them all, If possible without running new runs. Still havent taken new basement temp reading. Should be real cold this weekend so I hope to do them then.

 

[velvetfoot]

I was down in the basement today - - I should do it more often.
The temp was about 43F according to the hibernating dehumidifier (note to me: get some remote temp units).
The heat is oil hot water.
The basement ceiling is insulated (the way the house came - 3 years old), the walls aren't, the sill has fiberglass, there is a fair amount of exposed wall (walkout).
I am thinking now that I might have shot myself in the foot by putting covering a bunch of the basement pipe with foam; it would act to warm up the basement some when the boiler ran, no? If I insulate the walls the effect would be magnified.
Perhaps insulating the walls and putting another zone in the basement with the thermostat set at some low number to prevent freezing is the key; seems like a lot of work if the basement is not a living space considering the insulation in basement ceiling mentioned above.

My current thinking is that the original builder should have insulated the walls, although there are a fair amount of items attached to the walls such as the breaker panel and wiring and the main drain piping and cleanout-I guess if I retrofit I would have to box them out so those areas are not insulated. The panel would be too difficult to move and the traps with the drain pipe could freeze.

Just ruminating.

 

[elkimmeg]

velvefoot at 43 you pipes should not freeze If real concerned use a fan and blow air at the pipes you are concerned about 43 degree air moving at the pipes should do the trick with no heat source in the basement and well insulated ceilings insulating the wall does nothing unless you plan to make it living space