Any architects on this ng from southern Louisiana? Would like to discuss insulation in walls vs. attic. I suggest a 30R for attic and only 11R for walls (4"). There is a myth out there that walls need to be 6" to give southern walls adequate insulation. Crock of grits! I bump into someone who keeps this myth going every now and then (like now - client - who happens to be an engineer who thinks he knows more than God).
First, go here:
Or, if he's not in a "flood" area, then here:
They have building codes down there? You can do r13 in 2x4s...
Yes.
Thanks. The R values are close to what I suggest in my plans. Minimum R11 (I think I'll go up to the 13, however) in the wall and I'll stick with my R30 vs. R20 in my attics. This gives me something to show the guy. :)
I know that the walls don't need 6" of insulation in southern Louisiana. This pdf gives me something to show the guy. We did all the heat gain/heat loss calucations in college with brick/stone wall, stucco wall and siding ad nausem.
>
The Building Science guys know their stuff. They've approached it all from a physics standpoint - what really happens and how can you really build it. 99% of the time, I do what they recommend. It's really hard to go wrong with it...
Note that they recommend using rigid at the perimeter wall... Something you don't see everyday, usually.
That's true. Usually, people use the "pink stuff" (fiberglass).
>
Ditto here @ 32 degree longitude and, I think, you're around 40 degree.
Difficult to do in practice. Contractors have to take it seriously, as do you when reviewing. The gaps are what kill you. I've done it a couple of times in limited areas in reno work.
Why is that?
I understand now. I was just wondering what about it you didn't like.
I have worked on a project where the owner requested "Blue Wood" for the framing. What I understand is the "blue" is a coating that preserves the wood, prevents the wood from mold and the like. It doesn't have anything to do with the insulation. If you know that felt or other building paper wasn't used over the 'blue' then it must do both, building paper and a wood preservative. I know if you search "Blue Wood" with Google's you will find out exactly was it does.
CID...
Here is the web site for BLUWOOD:
"Jude Alexander" wrote in news:Cxwdj.47669$ snipped-for-privacy@bignews1.bellsouth.net:
Why is more insualtion bad?
I lived in a place here (Houston area) with low insualtion, and this place (decent insulation). I could feel the heat (and January chill) through the walls in the other place, feel lots less here. Main loss ia the windows - double-paned, but the sumbass aluminum frames radiate like mad - had great ones in Canada, wish I could recall what type/brand they were (that was
1993, so I've forgotten).Air-conditioning is a lot more expensive than heat, so it always mystifies me that people think you need less insulation in a hot (esp a hot and extremely humid) climate.
YOu might call it a myth, but personally, I'd take more/better insulation over less insulation ANY day.
I also got tech-shield and tyvek. I guess that, in your book, that makes me an even bigger idiot. I'm not an engineer and I certainly don't think I know more than God, OTOH, I *do* know what my energy bills say, or more to the point, *don't* say.
"Don" wrote in news: snipped-for-privacy@news3.newsguy.com:
We have fiberglass in the framing, then 3/4" blue foam (string board at the corners) and Tyvek over that, then the brick (hardi-plank on the second storey). I'd like mroe insualtion in the attic, tho'. We have the blown- in kind but I'd like to put somnething over that, maybe the thick rigid foam.
"Don" wrote in news: snipped-for-privacy@news3.newsguy.com:
But it's not as though heat transfer only occurs when the cool air is outside the building.
But isn't that like saying that a hot roast put into a box will cool down if placed in the snow, but a pint of ice cream in the same box would not melt in placed out in the hot weather...? Entropy always occurs - molecules in an excited state (heat) will preferentially seek a non- excited state (cold).
All I know is that, even aside from entropy, I've spent some summers in non- or poorly-insualted places, and the walls felt hot, meaning, the AC had to work harder to overcome the huge numbers of excited molecules which are available to exchange their energy state with the preferred non-energetic/cool state. OTOH, a well-insualted place will not have warm or hot walls, or at least, they won't be *as* hot/warm.
WIndows are another matter - as I'd mentioned, we'd gotten replacement windows in the first house in Ontario, and in Winter, the windows were warmer to the touch than were teh walls, IOW the windows (and their frames) were better-insulated. In this place, teh windows are double- paned but they suck - a lot of heat-exchange occurs because the frames are single-layer aluminum. IOW, crap. Also very difficult and expensive to replace, because they are basically mortered into the brick.
I of course can't speak as to r-11 versus r-13, but given the cost of air conditioning, which ain't about to go down, given that most electricity is still generated by burning either coal or gas, is a little extra insulation THAT much of a "wasted expense"...? What are the long-term figures? I mean, some people thought we were nuts for "wasting" money on the tech shield, but the figures indicated that, in this climate, it'ds pay for itself in jsut a couple years.
I just don't think that extra insualtion is as pathetically stupid as the OP intimated by the tone of the post.
"Don" wrote in news: snipped-for-privacy@news3.newsguy.com:
[ snip ]
THat's a good idea, I prob ought to check into setting something up
*before* anything like that happens...How much does it save? I mean, both up-front, *and* including what one has to gothrough to remedy all the eventual problems...?
It increasingly seems to me that most "savings", really aren't...
Those the tips re: the batting are excellent. I wouldn't have thought to do any of that. In a hot wet climate, does the paper go upwards, or does it face down (where the ceilings are)? I know I could aks the sales doodz at Home Depot or Lowe's, but I don't trust them to know...
One thing for sure, to work with fiberglass, I would get one of those disposable hooded body suits, face mask, gloves, and so on - fiberglass is great as insualtion, but it is also nasty if it gets into your skin or lungs.
Hard part will be clambering over all of the ducting - it's flexible, but it's everywhere (and I'm not as limber as I used to be, more like lumber, heh...)
Oh, yeah... smart idea!
I'm assuming I would have to get some of those styrofoam forms that you insert between the studs (of the roof) to be sure that the insualtion doesn't cover the soffets.
BTW, what do you think of putting nylon door/window screening over the soffits, on the inside, to block bees and whatnot? I don't know whether the holes (we have hardi-plank soffets) are small enough to keepout bees.
ANyhoo, thanks for the practical tips. I feel like I ought to send you something ;)
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.