Aces High Bulletin Board
General Forums => The O' Club => Topic started by: eskimo2 on August 01, 2005, 01:35:13 PM
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Our home was built in 1955. It has typical walls: plaster interior, 3 & ½ inch wood framing with 3 & 1/2 inch fiberglass insulation, 5/8 plywood sheathing and some cheesy (but durable) pressboard siding. There is no tar paper vapor barrier. I’m guessing that R value is about R-14 at best because of drafts. The siding is not doing well in places and we want to install vinyl siding ourselves. I’m not happy with the wall insulation; in the winter some exterior walls are cold to the touch. Obviously, the time to add any kind of insulation and vapor barrier is while we reside the house. After tearing off the old siding, we are considering several options.
A. Tyvek & siding.
B. 1” Foamular Rigid Insulation, Tyvek & siding. (will add about R-5 for about $600)
C. 2” Foamular Rigid Insulation, Tyvek & siding. (will add about R-10 for about $1200)
D. 1” Foamular Rigid Insulation, PRODEX Foil-Foam-Foil insulation & siding. (will add about R-19.5 {I call B.S.} for about $1100 – Tyvek cost?)
E. PRODEX Foil-Foam-Foil insulation & siding. (will add about R-14.5 {I call B.S.} for about $500– Tyvek cost?)
I don’t mind spending the money, we are going to be in this house for quite awhile, gas prices are high and this house sucks (heat). Obviously I want to make a wise choice and don’t want to create too much work for myself.
One problem with the Foamular is that it will add thickness to the house which means that the windows will be set back and will require some funky trim work around the windows. Another issue is how to install the siding with foam over the plywood sheathing. Do we just use really long nails?
I have serious doubts about the PRODEX Foil-Foam-Foil. I have repeatedly read that insulation cannot be achieved without thickness; I have trouble believing that ¼ of an inch of foam and foil can produce an R value of 14.5. I also have concerns about it containing all vapor and not breathing like Tyvek. However, I did see a sample of this stuff a long time ago; there was a display in a hardware store that had a tube, closed at one end, of this or something similar. The display asked folks to stick their hands in the tube; I did and it was amazingly warm. The instant I stuck my hand in I could feel the reflective heat from my own hand. Obviously We wouldn’t need Tyvek if we opted for this stuff, so the price would be $500 minus the Tyvek cost (which I have no clue).
Links:
Foamular Rigid Insulation: http://www.owenscorning.com/around/insulation/products/foamular.asp
PRODEX Foil-Foam-Foil insulation: http://www.insulation4less.com/highr_FfmF.asp
If you have dealt with any of this before, please voice your opinion. If you have any alternative ideas, please let me know.
Thanks,
eskimo
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I would like some to explain the value of the foil too. Eskimo, you might wish to take a look at your other two sides as well and add insulation there.
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I have a good friend who know quite abit about insulation. The BEST way to go is that spray in foam stuff. Its more expensive but its like living in a Thermos compared to fiberglass. Im not familiar with the rigid foam you mentioned, unless its the blue or pink foam boards. Seams is seams.
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Originally posted by FiLtH
I have a good friend who know quite abit about insulation. The BEST way to go is that spray in foam stuff. Its more expensive but its like living in a Thermos compared to fiberglass. Im not familiar with the rigid foam you mentioned, unless its the blue or pink foam boards. Seams is seams.
We have insulation in the walls and it wouldn't be practical to tear them apart to replace the insulation. We are looking at adding something between the ply sheathing and new siding. Much more could be gained in this manner.
Thanks,
eskimo
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O no not owens corning
aaargh
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I can't believe that no one has an opinion or advice on this...
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Hehe..i did.
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Foil is a radiant barrier, simple as that. Close celled foam is better than open, and the more(thicker) the better. Every dollar you spend on insulation will amply repay itself down the road.
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What value does a radiant barrier have? Is it measureable or more theoretical? if I was redoing a room should I think of doing it?
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A radiant barrier is a foil. The equivilent material is measured in inches. R value is a crap measurement, but what it measures is heat transfer through the wall. U is better, but a new standard is being written as we speak that will address the other issues, namely thermal mass. Regardless, a radiant barrier is generally good.
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Thanks, Have any idea what kind of payback it might have? Its not that expensive but I'm still wondering if its worth my time. I see some pretty spectacular claims about its energy savings but I wish I knew from someone who is not selling the stuff.
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I don't sell it, I sell the competing product. My product, however is not a good application for what you are doing. As far as the thickness of the insulation, go with a 3/4 inch foiled foam and make sure you flash and seal the penetrations. Payback will be noticable on your energy bills.
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BTW, if you are comfortable applying the siding, there is no reason not to insulate it yourself.
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did you get my PM Liz?
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Let's do it here so others can chime in. Can you do a simple floorplan layout, and make the interior walls being removed as dashed lines? I didn't really understand about the flooring. Does it need to be replaced?
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OK,
The area is 35 X 30 which includes the living room, dining room area and kitchen/pantry.
The ceiling is being trussed up to get rid of interior load bearing walls and all of the floors need to be refinished. I'm going with red oak unless I hear better ideas.
For the ceiling, I was intending to use R38 fiberglass bats and the outer walls that are being built will be 2X6 although thats not much considering there is just 6ft on the side and the 30 ft exterior wall that is the living room and dining room being pushed out is comprised of a 12ft slider, 8 ft picture window and french doors. What matters from the insulation point is the ceiling and floor. The 6 ft by 30 ft area being created by pushing that wall out is currently a cement floored porch. there is about 3 inches of floor depth which needs insulation but I'm not sure what.
Ya, it's a brain full...> Any good ideas? how do I figure out the value of the insulation? 1 sq ft of R38 bat buys me what energy savings over just drywall in the ceiling? If I add a radiant barrier does that take off so much per square ft? Whats my best bang for the buck in the insulation world and what kind of payback does it entail?
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Originally posted by Lizking
BTW, if you are comfortable applying the siding, there is no reason not to insulate it yourself.
That's my plan. There's almost nothing on a house I won't do.
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Sorry, long day at work. What kind of support are you adding to the rafter plate column-wise under the trusses?
A simple way to look at insulation is to break it into 3 types:
The First is Radiant heat shielding. Simply put, any film that reflects a large portion of heat energy directed at it. It is not critical that it be a perfect fit, like the moisture proofing should be.
The Second is "dead air" space. This is, at it's most basic, how insulation of most types work. Air is an excellent insulator, provided it is not allowed to mix freely. Foams work well because of the multiplicity of surface area involved. Things like the white styrofoam are good, but they are open-celled, that is, they allow air transfer. The wallboard foams are closed cell, and the more expensive it is, the smaller are the bubbles, and thus the insulating value.
The third is thermal mass, which has no application here.
I can't give you any calculations without climate and existing structure data, but it is usually substantial, in the 30% range.
If I were going to build a stick house, my wall makeup would be (Central Texas climate):
From the inside, out:
Doubled 3/8" ****rock-2x6 stud w/batts-OSB-Tyvek-furred 3/4" foiled blue board-1x6 shiplap siding. Properly flashed and weeped, of course.
Ceiling vs wall insulation depends upon your climate data as well.