Author Topic: Home Exterior Insulation Options. (Read 508 times)

eskimo2 · « **on:** August 01, 2005, 01:35:13 PM »

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

rabbidrabbit · « **Reply #1 on:** August 01, 2005, 01:39:59 PM »

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.

FiLtH · « **Reply #2 on:** August 01, 2005, 01:59:01 PM »

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.

eskimo2 · « **Reply #3 on:** August 01, 2005, 02:08:33 PM »

Quote

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

BUG_EAF322 · « **Reply #4 on:** August 01, 2005, 04:09:50 PM »

O no not owens corning

aaargh

eskimo2 · « **Reply #5 on:** August 02, 2005, 05:07:58 PM »

I can't believe that no one has an opinion or advice on this...

FiLtH · « **Reply #6 on:** August 02, 2005, 06:40:29 PM »

Hehe..i did.

Lizking · « **Reply #7 on:** August 02, 2005, 06:53:56 PM »

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.

rabbidrabbit · « **Reply #8 on:** August 02, 2005, 09:27:32 PM »

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?

Lizking · « **Reply #9 on:** August 02, 2005, 09:37:48 PM »

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.

rabbidrabbit · « **Reply #10 on:** August 02, 2005, 10:06:19 PM »

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.

Lizking · « **Reply #11 on:** August 02, 2005, 10:28:59 PM »

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.

Lizking · « **Reply #12 on:** August 02, 2005, 10:30:26 PM »

BTW, if you are comfortable applying the siding, there is no reason not to insulate it yourself.

rabbidrabbit · « **Reply #13 on:** August 02, 2005, 10:47:50 PM »

did you get my PM Liz?

Lizking · « **Reply #14 on:** August 02, 2005, 10:55:03 PM »

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?