Insulating an attic used for Storage?
So after a bit of looking around I’m rethinking my wall insulation (for now) and making sure I’ve got the attic insulated the best I can. The problem is in my little house I need the attic for storage so can’t just blow a ton of Cellulose in there or lay down bats and bats of fiberglass.
What I have now is a wood plank floor (it was there when I moved in). Every indication is it does have some insulation under it (I’ve never pulled any of it up but it does stick out at the ends.) I plan to go around first and plug every orifice I can find (vent pipes and such). But even with that I’m guessing the attic floor/2nd floor ceiling is still going to leak warm air like crazy. The Floor/ceiling joists can’t be more than 8-10 inches from what I can see.
So what is the right way to do this? Right now I don’t get any ice dams (live in the Northeast, Boston) and the Attic is very cold in the winter (enough so ice forms on the roofing nails that penetrate it. There is no ridge vent or soffet vents. I could pull up the floor in sections remove the old (and I’m sure compacted and filthy) fiberglass batts and spray dense cellulose but I’m guessing this isn’t going to be particularly thick? And what about venting the attic. Do I spray foam the roof? Put in Soffet and ridge vents and vent it from the soffet to the ridge behind the spray foam? Could I build up the rafters so I have a Raised floor in effect and get in more cellulose?
Whose got a good suggestion for this one?
Replies
This Q in various forms has been discussed a bunch here. For my two cents I would foam the underside of the pitched roof and bring the attic into the heating zone. Then you don't have to mess with the attic floor and head clearance. BTW the recommended R's for an attic in Ma is R 49. Which if you were to blow in cellulose would translate to about 1 foot deep.
Thanks for the input, what I'm finding, based on estimates for my walls is that the foam suppliers have gone crazy with their newfound popularity and made their product unaffordable to the average home owner (or at least this one :-) Add to that the installation of a ridge vent (more cost) the whole cost is more than I can afford. Given the amount of "STUFF" in my attic this is another job that will have to be done in steps. Again cost of bringing the foam guys in repeatedly seems to exclude them.I think the foam is a great product, but if the attic is full or any room needs to be partially used during the application it's not a reasonable alternative. I don't own one of these monster homes so don't have tons of spare room to clear out my attic to in order to do this for a job.ThanksEdited 4/12/2005 9:19 am ET by Ribs
Edited 4/12/2005 9:25 am ET by Ribs
If you have ice on your roofing nails, you definitely have moist air getting up there from in the house. Sealing up the penetrations in the house ceiling/attic floor should help that a lot.
Brain cells come and brain cells go, but fat cells live forever
Hot roof debate not withstanding, you should'nt have to remove every thing from your attic to insulate the pitched roof. Just shove every thing to one side then the other. Of course maybe you need to have a yard sale first to fund the project.;-)
You could always try to foam it yourself.
http://www.fomofoam.com
ribs... we do this a lot...
we'd go up in the attic... you say you have 2x8 floor joists in the attic ?
pull up the board flooring .... add a 2d layer of 2x8 joists crossing the first at right angles...
replace your board flooring over the new layer...... leave a few boards out so you can blow cellulose into the new 16" space.. install these last boards after you finish blowing
you can dens-pack the cellulose.. at the eaves, make sure you have dams to prevent the cellulose from blowing out into the soffits
I would foam the floor that will effectively seal all vapor from getting into your attic and ruining the insulation (foam isn't affected by moisture like celluliose is) and then do a staple up of fiberglas on the roof rafters.. , You'll need to put eve vents in and a vent at the peak but if you do this properly you should be able to capture some of the lost heat. The trouble with trying to find every heat leak in an attic that you don't have a great view of is that it's near impossible, if you should miss even a small leak then vapor will get into your attic and make the celluliose damp.. Once it's damp it's effectively not there.. (other probelms may happen)...
As I said to Reinvent above, clearing my attic out to rip up the whole floor and foam it probably is not a reaonable alternative. That and the foam prices being what I consider ridiculous has ruled it out as an option (at least for now). I need something I can do on my own (foam unfortunately does not fall under that category).Thanks for the input though. I do belive in doing things correctly so in the long run I may end up changing my mind and going with the foam. Not sure how I'm going to afford it (at least right now). Maybe once the kids are out of daycare.Ribs
Wrestling with the same question, I have a walk-up attic, and I have soffit and ridge vents, and an air handler in the attic. Right now my thought is to at least partially insulate the attic so it will be "a bit" in the envelope. So cotton insulation (+ VB) in gable end walls. I don't want a "hot roof", I'm not sure all the issues are worked out there (e.g. closed cell vs open cell foam -- well that should get some comments). I've heard the suggestion of foam board over the rafters, so the sheathing is still ventilated. In general I like foam because I worry about the VB being on the wrong side half of the year. But foam requires DW thermal barrier and I'm not sure my 2x6 rafters can take it. There are also a couple of other issues with baffles over the vents. Such as, gotta ventilate the moisture from the envelope (hard to stop it with walk-up). Also I was planning on installing one of those Tamarack whole-house fans, but that relies on the attic being ventilated.