Insulating a floor over ground
I will be installing radiant heat flooring (warmboard brand) in an existing 16′ x 16 – 3 season porch. Current flooring is 1 x 6 PT which will be removed. Floor is about 3 feet above ground. For insulating between the joists should a vapor barrier be only on the living space side?
Any recommendations as to fiberglas sbatts, loose fill, etc??
Thanks,
Tom
Replies
where are you located?
If a cold climate, don't just rely on insul under the floor: enclose the space and insulated the perimeter.
No vapor barrier in/next to the floor....
May your whole life become a response to the truth that you've always been loved, you are loved and you always will be loved" Rob Bell, Nooma, "Bullhorn"
"We Live" http://www.youtube.com/watch?v=7kuBgh0VCqI&mode=related&search
And Annie Ross's "Twisted" http://www.youtube.com/watch?v=8lqivrCIRGo&mode=related&search=
Thanks, I'm in Tolland, CT.
Not as cold there as when I was in VT, but the word there was a floor open to weather below would always be cold no matter how much insulation you put in.
May your whole life become a response to the truth that you've always been loved, you are loved and you always will be loved" Rob Bell, Nooma, "Bullhorn"
"We Live" http://www.youtube.com/watch?v=7kuBgh0VCqI&mode=related&search
And Annie Ross's "Twisted" http://www.youtube.com/watch?v=8lqivrCIRGo&mode=related&search=
I would agree that would be the case with conventional heating but by going with radiant heat tile floors and 12" of insulation under the tile I thought I'd be OK. I'll see what the NRTradiant people say. They sell the pumps, manifolds, etc. for Warmboard.
Anybody out there have experience with the Warmboard (warmboard.com) product?? Thanks all, tjm.
How is the edge of existing porch handled?
If it's on a perimeter wall, it's probably better to insulate that wall, then up into the new work.
The buildingscience site has some good examples of this--even if they are now much harder to find <sigh> check under designs that work, which is under building physics)
Check out Figure 5 here: http://www.buildingscience.com/documents/primers/plonearticlemultipage.2006-11-14.1183847686/section-2-the-basic-cold-climate-house/
Now, if there's no perimeter wall, that could be a bit more interesting.
One wall is the house, 2x4, blown in cellolose plus 1" rigid insulation.
The other 3 walls are 2x6 kneewalls, R-19, about 3' high, brand new double pane, double hung windows.
Space is cathedral ceiling, 2x10 rafters, R-30 with the 2" airspace.
I have Warmboard doing an analysis of the whole house heating needs so hopefully this is a viable project.
The other 3 walls are 2x6 kneewalls, R-19, about 3' high,
Ah, but what is underneath that? The actual foundation? If the "new" floor is open to air, that's a bit different than a ventilated crawlspace is a bit different than basement or cellar, too.Occupational hazard of my occupation not being around (sorry Bubba)
For now it is wide open, 3'-4' off bare ground. A previous post suggested putting a wall down from the rim joist to the ground. Makes sense if for nothing else than to reduce the winds from whipping across the bottom driving up the convection coefficient. I presently store the wheel barrow, some ladders, lumber, etc. under there. Closing it off would "secure' the items, not that I've ever lost anything. Aesthetics would also be improved. I built the deck/porch in '97 and planned on closing in the perimeter but we all know how that goes sometimes.
Any suggestions? cinder block (ugly) stick frame/sheathing with faux stone ($?)
Picture worth a thousand words, I'll figure out how to post one tomorrow.
Any suggestions? cinder block (ugly) stick frame/sheathing with faux stone ($?)Picture worth a thousand words, I'll figure out how to post one tomorrow.
Well, your town/city may have rules on how deep such a wall has to be. So, you may have to get in under the edge and set a footer.
Now, upon that footer, you have many options. ICF (insulated concrete forms) might be a very slick option--since you get some insulation value that way. Ok, ICF will be a hair more complicated since you have a "room" where "we'd" pour the concrete in the forms. But, "regular" concrete block will wind up similarly.
What I can't answer is if adding this perimeter wall "does" anything weird to your existing foundation supports. There's a jurisdiction near me that is picky that way--you put in what looks like a load-bearing foundation wall, then it has to be one--even if not needed <sigh>.
Me, I happen to think cultured stone makes for an elegant near-no/low maintenance exterior finish that does not add more thermal complications (you should see the folk running sprinklers against their brick-veneered houses around here).
Or, you could just work up a way to seal up the floor, close it right in, treating it like it were an upper-level cantilever. With the knowledge that is an entire case of worm cans to get into, too <sigh>. But, sealed up tight, then you could just set a "garden wall" using split-face os such like block to secure/prettify the room-to-ground connection. Or not.Occupational hazard of my occupation not being around (sorry Bubba)