Need some Opinions!! Insulate the Basement Ceiling??

[Jay H]

The expanding stuff is fun to use but definitely wear some kind of glove, getting that stuff off your skin is a major pain. I've had good luck with reusing them too although the brandname "Great Stuff" says don't expect multiple uses. I washed the nozzle off of the brand I've used (DAP company) and reused the straw and stuff but it doesn't seem as sticky or as expanding as Great Stuff brand. I just couldn't justify one time use unless you can categorize every single hole/gap you find.

Jay

 

[jqgs214]

BG, to be honest I dont care if the basement stays at 50deg. I just dont want that 50* affecting my living space temps. Now if that means insulating the ceiling then fine. Elk i highly respect your opinion, I guess I just want to have more validation that putting fiberglass bats up that I'm going to see some significant results without lowering the temps to freezing in my basement. Assuming of course that I take care of major leaks at sills etc.

 

[tw40x81]

Would anyone ever consider using a DIY spray foam kit such as this? http://www.tigerfoam.com/products.php?cat_id=1

 

[begreen]

BG, to be honest I dont care if the basement stays at 50deg. I just dont want that 50* affecting my living space temps. Now if that means insulating the ceiling then fine. Elk i highly respect your opinion, I guess I just want to have more validation that putting fiberglass bats up that I'm going to see some significant results without lowering the temps to freezing in my basement. Assuming of course that I take care of major leaks at sills etc.

Agreed. If the basement stays at 50 degrees with the floor insulated then I would go ahead and insulate the floor, but with caveats. Elk has brought up good points about service and later remodeling access. I knew this would be happening in our space and was one of the reasons I chose to do the walls and to not use foam. I can still work on everything without obstruction. The only problem is that its too warm down there now and I have to work in my shirtsleeves.

 

[jqgs214]

Ok BG now how do I know if its gonna stay near 50 before I insulate?? Will the temp readings help that?? Rhom?

 

[homebrewz]

Is it feasible to insulate the sill plate from the inside of the basement? If fiberglass is not recommended, would foamboard be acceptable?

 

[begreen]

I used foam board + fiberglass on the sill as per www.buildingscience.com.

WX, I can't answer your question with specifics, you would need to run the calculations and observations based on a site inspection. But this document should be a helpful start:
http://www.buildingscience.ca/docum...sics/thermalcontrol/heatflowbasics/insulation

 

[velvetfoot]

Our house which is a couple of years old came with fiberglass insulation in the basement ceiling. It's like puffy clouds down there. It covers all the pipes and wires and stuff which makes it a little hard to see what's going on, but since it's press fit, it comes out easy too. Of course you get the fibers airborne then. Our house has a fair amount of exposed concrete basement wall, so that doesn't help heat loss. What's a little disconcerting is that the stairway going down to the basement is not insulated. I wouldn't be adverse to finishing the basement, but all the junk that used to be in the garage is down there now that the garage is populated with a couple of wood splitters, trailer, and a pile of split wood.

 

[homebrewz]

I used foam board + fiberglass on the sill as per www.buildingscience.com.

WX, I can't answer your question with specifics, you would need to run the calculations and observations based on a site inspection. But this document should be a helpful start:
http://www.buildingscience.ca/docum...sics/thermalcontrol/heatflowbasics/insulation

Good website. They show a sill gasket material on the outside of the sill. Quite a project on an existing structure. I was wondering if it would be helpful to insulate the inside of the sill plate, inbetween the joists, or is it a waste of time because it should ideally be placed on the outside.

 

[elkimmeg]

I glade this discussion is occuring over the past two weeks many posters complained they are not getting the heat they expected using their wood stoves.
One thing in common no preventive measures taken, addressing the first floor basement issue. As hot air rises it draws in replacement cold air from below.
I seems, that if one could reduce this occurance then one would benifit from the heat generated and reduce that which is lost to an un insulated first floor cellar ceiling.

I wonder how many have blamed the stove for lack of preformance, when it is a tremendeous heat loss elsewhere.

Its the older homes a built before 1980 mwhere sill leakage is common. Today codes require sill seal under the first box plate and the top of the concrete foundation.

All replies here agree,, that the sill and foundation leakage has to be addressed. Dissagrement comes in the best method of doing it Personally a common cauling gun might do the job
othere use the wick and cans of expanding polystyrofoam. Stuffing in fiberglass insulation also eliminates drafts

The next issue to address is the box sill usually 2/8 or 2/10 the space above the sills inbetween the floor joist.

Some suggest cutting rigid stryofoam others use fiber glass batts. Either way this area needs to be addressed

The third option is cellar joist cavity insulation before I get into that it is suggested it might be better to address the walls Not a bad suggestion but without a heat source it will do little to prevent that below grade cellar concrete slab from emitting quite cold air infact the insulation on the walls will actually force more coldness out of that concerte slab.
Therfore there is merit to insulation the walls but one still has to prevent the cooler basement from drawing heat from the living space above
The ceiling still needs to be insulated unless there is a heat source in the cellar designed to heat that space

So there are two solutions insulate the walls and heat the cellar or if not planning to heat the cellar then the ceiling insulation needs to be addressed.
Again there is disagreement as to what kind of insulation to use. If doing the work and on a tight budget then Fiberglass wins IS it best R value probably not
Foam filled cost 2x more to be done and all wires ducts and pipes get burried and concealed within the foam. A minor plumbing leak becomes a very costly repair. and very hard to find
Future remodeling needing curcuits of curcuit pannell up grades cost just doubled or trippled there is noway to pull wire slack if needed with foam What does on do about junction boxes that get burried? Another cost to move them. What about water valves that get burried? What about sink tubs and toilet traps that get burried? cleanout burried?

Another way to insulate is to cut ridgid styrofoam and install it between the bays homeowner doable cost a bit more and probably requires 2 1" layers to equal R14 and 3 to equal R21.

It will cost more than fiberglass but I let others argue the pros and cons

 

[velvetfoot]

I don't believe you can leave the rigid styrofoam without a fireproof covering which equals 1/2" of gypsum board in a basement. You can't just glue it to the walls either and glue the sheetrock on it because it could fall in a fire, I guess.

 

[jqgs214]

Elk,

Thank you, seems that maybe we all agree that my basement ceiling should be insulated to reduce flow to the main living space. Fiberglass bats seem easier to install to reduce flow then tring to cut rigid board tight and then what tape the seams?? Since I am not heating the basement (ever!) my only concern should be to make sure the sills are tight first so that the basement doesnt get too cold and freeze my pipes. Does this sound right? or am I too concerned with the pipes freezing part considering where I live and my basement temps now. (will measure those tonight and post so others have some comparative #'s) Also one more question Elk, do you think given my conditions that I will recuop that 500-600 insulation investmentand (wow I started a 3 page thread!)

 

[ansehnlich1]

wxman, i read this whole thread. my wife and i are building a new home and we're insulating the whole dang thing with fiberglass. now i know some will say that's not the best way to go, and maybe it ain't, but i don't want that spray foam all over.

it is code here in new home construction, you HAVE to insulate your basement walls. they take this foil faced fiberglass insulation and bold it right to the walls, does a great job, had a house in Maryland that had it. yep, the entire walls around the basement are done.

also important to seal your sill plate area and between the joists up against the bandboard, like talked about here. my new house will have fiberglass insulation in there and that's fine by me.

also, WEAR GLOVES when using great stuff spray foam, i just used about 15 cans of it sealing around my windows, they have a special mix at lowe's for just windows and door frames, anyway, i didn't wear gloves the first couple cans and sure enough, gasoline, paint thinner, you name it, nothin takes it off. (80 weight sandpaper maybe)

 

[ansehnlich1]

oh yeah, and i forgot the title to the thread.....

i wouldn't insulate the floor between the living space and basement, i'd do the walls, sillplate, and bandboard areas only.

 

[johann]

Hey its winter and I'm new to the board with a house built in the 1920, balloon construction, boiler in the basement but non-heated and thinking of getting a fireplace insert on the first floor.

So whats band-board?


You all have me sold on checking out the sill-plate styrofoaming the basement walls and then fiberglass battoning the cieling in the basement. my only trouble is that all the wires in the basement ceiling were not drilled through. I assume i'm going to have to rerun them so i can insulate the ceiling and then drywall it?


cheers1

 

[Rhone]

The point of my post, is to point out that if you use Fiberglass

1.) It is the worst insulation if you have air movement. So make sure you caulk or foam up any possible air leaks and pay particular attention that as you install it, you don't create channels in it (like long gaps at the edges that are like wind tunnels).
2.) It's nearly impossible to install correctly, it acts more around 50% rated value. Expect R11 batts to insulate slightly worse than R5 foam.
3.) As temperature difference increases, the effective R-Value of fiberglass decreases. That doesn't really matter here, your basement is 50F.
4.) Pay extra attention to detail with it to attempt to get as much R-Value as you can out of it. To install it correctly, it shouldn't be compressed (in a floor situation you really don't have a choice), each piece should be fluffed to it's proper height before installation, a putty knife used to make sure the edges are flat & tight with the edges as possible, it's cut around all obstacles, and that you leave no air gaps on the sides or between pieces. I've never seen a construction crew fluff, use a putty knife, install it without gaps, nor cut it around obstacles besides the obvious ones. The author of one of my energy books after doing some tests ripped it out of his attic and put blown cellulose. He said, the improvement to comfort was amazing, and if an insulation author who painstakingly installed each piece of the fiberglass in his own home can't get near the rated R-Value how is Joe Homeowner or a Construction crew supposed to.

I don't need the temperature differences. I was trying to determine just how much insulation should you put in your floor but the answer is R5. So, you can put R11 in there and hope you get at least R5 out of it, or put R5 foam boards in there and should save you around a cord/year. Moving that up to R10 foam or R19 fiberglass you improve that to 1.2 cords. I think if you figure out the cost of going from R5 to R10, it's not worth going higher than R5 (so either R5 foam or R11 fiberglass should get you there).

 

[ansehnlich1]

So whats band-board?

cheers1

the band board is what we call around here that pereimeter joist that goes all around the house that sits on the sill plate....it's what the flooring joists run up against, you see it between your joists in the basement at the top of your basement walls....here's a pic of a guy tryin to work up in there

http://www.deck-lok.com/images/step1-2.jpg

 

[jqgs214]

Thanks Rhon, One more point I just realized that I forgot becuase I was at work. My 80year old house has tongue and groove subfloor covered with hardwood covered with pad and carpet. Seems to me the old subfloor- some gaps between, the hardwood (old with gaps between) only really some pad and carpet stopping flow where the gaps line up. Now does it make more sense to insulate the ceiling of my basement? Putting meter down stairs now to get some temp readings. I know ya dont need em but what the heck.

 

[jqgs214]

ansehnlich1,

Guess i'm just dumb but I dont see insulating the walls doing much for me. I'm not heating the basement, just trying to keep the basement air outa my living space. 55 degree earth and 8 inches of block really let in that much cold air?

 

[GVA]

You all have me sold on checking out the sill-plate styrofoaming the basement walls and then fiberglass battoning the cieling in the basement. my only trouble is that all the wires in the basement ceiling were not drilled through. I assume i'm going to have to rerun them so i can insulate the ceiling and then drywall it?

You dont have to rerun the wires just put some strapping up against the joists first...
Only problem with covering with drywall If you have any 4" squares (these are those steel boxes for electrical connections) in the ceiling you can not cover them, as all splices or connections must be accesible. My basement is loaded with them... So no drywall for me.

 

[Highbeam]

So whats band-board?

AKA Rim Joist.

 

[Gooserider]

ansehnlich1,

Guess i'm just dumb but I dont see insulating the walls doing much for me. I'm not heating the basement, just trying to keep the basement air outa my living space. 55 degree earth and 8 inches of block really let in that much cold air?

IMHO weathersealing the air entries into your basement and possibly insulating the walls at least above ground level will do more for you than insulating the floor. If you seal the basement it will keep a good bit of your heat from escaping, probably warming the basement some (which I realize isn't a major objective) but also moving the equilibrium higher so you won't be loosing as much heat to the basement. Also if less cold air is getting in, there will be less pushing to get up into the house. If you are still cold, you can then insulate the basement knowing that the insulation won't have to deal with as much of a temperature differential.

If you insulate the floor without doing the walls and air leaks, you will end up with a much colder basement, which will make the floor insulation have to work harder, and not do as much good.

Gooserider

 

[ansehnlich1]

ansehnlich1,

Guess i'm just dumb but I dont see insulating the walls doing much for me. I'm not heating the basement, just trying to keep the basement air outa my living space. 55 degree earth and 8 inches of block really let in that much cold air?

Basement walls can account for 20 to 35 % of a homes heat loss. concrete and earth are poor insulators. if you have a dry basement i'd highly recommend it. do a google search on "why insulate basement walls" or " foundation wall heat loss".

 

[jqgs214]

Well Hearth.com does it again. Went down the basement and did the ole draft test and found some MAJOR air leaks around rhw sill in the basement. Some in hard to reach places so I gonna try some expanding foam first to stop the air flow. Even with the leaks I found the temp down there is still only 53.9*, I think some of the colder air is getting pulled right into my living space, it sure is getting sucked into the basement! Thanks again for all the input. Get the sills sealed and see how it goes from there. I'll keep ya updated on the results.

 

[begreen]

Way to go Wx. Even if you can only get the temp up to 60 the floors are going to feel much warmer. If not, maybe get your honey some down booties. I am curious about one thing, does your stove have an outside air kit or is it drawing air from the interior of the house?