Hey folks.
This is a good day for me since we insulated yesterday. But of course not just fiberglass, but spray foam. And I really have all the discussion here to thank for educating me on the virtues of spray foam. This was a huge step in making my vision of a great house a reality. Now if I could just get my butt downstairs and start making the kitchen!
To steal from Andy — “be keeping warm”
See attached.
Thanks -MERC
Edit: Just for the record, the roof is unvented.
Edited 12/1/2004 4:40 pm ET by DJ Merc
Replies
DJ: You are going to LOVE that foam. Best investment you ever made. See you went right up the rafters. We did also. Really makes a difference in the attic & upstairs. Winter and summer.
Don
Gotta love ya! You are now part of the secret inner circle where the warmth is.
But don't pay the installer 'till he scrapes the excess clean for you. No job is done 'till it's done.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Yeah....I'm the guy doing the cutting! But it's not too bad, I'm actually going to frame some lower ceilings in some of those rooms so most of the roof can stay just like it is.
MERC.
Don't you need to cover it all with sheetrock to pass fire code?
I asked my Building inspector about that. she said they don't inspect fire barrier...? I was shocked. She said as long as there was drywall between the living space and the foam she would be happy. The foam is also rated as non-combustible so I think it doesn't require a fire barrier like faced fiberglass done.
I sure hope it doesn't because I don't want to be drywalling all that stuff way up in the attic.
MERC.
Looks like Icynene . I got that stuff in my attic . well wort it.
I love this stuff. Our house is flat-roofed, with black EPDM as the membrane. Middle of summer in the Southwest, 90 degrees outside, high altitude sun, and the air temperature in the ceiling cavity between foam and drywall is the same as at the floor of the room. Others on the job site couldn't believe it.
The High Desert Group LLC
Was this a d-i-y foam job?
Any more details if it was and did you save any money by doing it yourself
It seems like I saw somewhere else that you had a link to fomo.com and that
was the product that you used.
I didn't DIY this one because it just wasn't cost effective and there were design constraints.
fomofoam stuff is high density foam (2 lb foam) and is about $1/bd ft. I had somebody who would have sprayed 2 lb foam for about $3.50/sq ft @ 4" depth. So it was just not cost effective.
However, as it turns out I needed to use a 0.5 lb foam (open cell) so that my roof could dry to the inside. That came in at $0.25/bd ft.
So in the end, I went from trying to swallow a $10k estimate for 2 lb foam, to paying about $6k for the open cell foam. So that worked out well because I had budgeted the $10k for foam.
After having seen the professional spray it, I would probably hire it out always. It was cheaper because the guy had the setup. He showed up with a big trailer full of A and B barrels and expensive equipment and expensive spray guns, etc. Also spraying this stuff is not pleasant, particularly overhead. It gives off fumes that make your eyes water and your nose run. I felt bad for the guy spraying it, but he refused to wear googles ("slows me down and we are busy"...uh, ok....). I'm not even sure googles would help, you might need sealed respiration (he had that too, but that "slowed him down" too). I stood there and watched him spray the last section of my roof and I felt my eyes starting to bother me. I was only there for 5 minutes.
I do almost everything myself where reasonable, and I don't classify this one as reasonable. The pros will produce a better job at less cost. It's a rarity in the building industry, but this is one case.
MERC.
thanks for that in-depth reply
do you know the r-value for .5lb foam per inch?
And how many inches did you have applied to your rafters?
and again, thanxs
Foams are the same R/inch regardless of density. Polyurethane is 7.14/in new and ages to 6.4 or 6.5. Polyisocyanurate, the open cell foam that's most likely what you mean if you say .5#, is about 3.5.
R-value = 3.81/in.
He came very close to completely filling the wall cavities, so I estimate I have a nominal 3.25" in the walls and the roof is probably a nominal 6", might be more. Much of my roof won't even be sawed so in some places the foam is 8 or 10" thick, other places it's more like 4". But the proof is in the pudding. The upstairs of my house is currently sealed from the 1st floor so it only gets heat by conduction through the subfloor. Last night was 22 here and the upstairs was 56 when I got up this morning at about sunrise.
One thing I should mention about this foam. It squeezed out every little crack, which is very good. However, it will find it's way onto finished siding, it squeezed out an OSB crack and ran down the sidewall onto a little roof I have on a box bay. It also squeezed out my ridge vent in one place (I put the ridge vent on to "fool" the roofing manufacturer if I ever have a claim - my roofer claimed they woudn't climb up on a 12/12 roof to see if the vents were working).
MERC.
Thanks again for your response
<It squeezed out every little crack>
Was this a problem with your roof decking, with a gap between the long edge
of plywood(assuming you had one). It seems like that the foam would create a
bulge in the roofing w/foam squeezing out between the cracks. I can imaginge
this "could" pose a problem if you had 1x decking
It would be something I would think about before spraying on 1x decking. I haven't noticed any bulges on my roof, but I also have very heavy shingles (50 year architecturals - 4 bundles to a sq). So those shingles would resist bulging and even hide small bulges. My guess is properly secured shingles would provide enough force to resist the expansion.
MERC.
My installers have a ful face respirator with air pump outside providing them with fresh air all day. They go thru about four face shields in a day.
Tyvek suitsBurns my lungs if I am too close, but don't notice it in the next room or the next day
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Also spraying this stuff is not pleasant, particularly overhead. It gives off fumes that make your eyes water and your nose run. I felt bad for the guy spraying it, but he refused to wear googles ("slows me down and we are busy"...uh, ok....).
He must be related to the guy in the attached pic.
jt8
How do you get the foam cut back flush with the surface of your rafters or your studs?
Is it feasible to install T&G directly under the foamed rafters without any other ventilation concerns?
My foamer gave me a 36" long serated blade that rides flush on the framing. He also had a couple of sawzalls modified to mount the blade offset from the body of the saw, but I just use the blade by hand (with cotton gloves dipped in nitrile so I don't get cut - those damn things are razor sharp).
The reason I cut the foam by hand is because the foam will push wires out of the wall plane. You can generally see them and get them worked back in, but it would be very easy to just slice one in half and rather difficult to fix.
If you wanted to install t&g on the underside you would probably have to slice some foam off. You could probably control it well enough to not have to slice it, but I'd rather get full R value and full air seal and have to slice it, it really only takes a few minutes. Foam is such a different animal than fg, you can really design it to work successfully without ventilation. As long as you understand the reason behind ventilation, you can successfully design an unvented roof assembly. I find that many people don't understand ventilation though.
MERC.
Yeah, after I posted that, I was thinking, "did I imply he doesn't understand ventilation", because that isn't what I meant. I know from your other posts that you know which end is up.
I'm wondering what would make moisture condense on the ceiling of a log cabin in the summer? It seems to defy logic -- air would be warmer at the ceiling, thus I'd think it would always be above the dewpoint. Unless you AC'd the cabin and you have major stack effect which would quickly carry moisture to the ceiling which would be the first surface below the dewpoint. Strange.
At any rate, I doubt this would ever happen with foam because there would be zero air movement through that roof, thus crushing the stack effect. In fact, my windows upstairs have not been sealed around the jambs and I have very little air infiltration because there is nowhere for it to go. Foam truly does reduce the heat loss problem to a conductive issue, in which case, as piffin points out, you actually need little R value to effectively combat these conductive losses. If I never buy fiberglass again, I'll be the happier for it. Foam truly is "Great Stuff" (sorry, had to do it....)
MERC.
Curious as to what you'll use for the roof. Some shingle makers won't warrant their product over an unvented roof, some will. Is there brand/type prefered for installation over an unvented roof? Thanks.
Yes, roof shingle warranty. Long story on that one.
I don't care about roof shingles warranties over unvented roofs. They are such total bullcrap, just more ways for them to get out of paying anything that they never really pay anyway.
I had roof shingles on the roof long before the entire insulation thing was worked out. I used GAF, which are not warranted unvented. However, I agreed with my roofing guy that if we put in roof and soffit vents, nobody was climbing a 12/12 to see if it was really vented. Besides, 50% of my roof is unventable (properly that is) due to valleys. So when the roofing guy pulls up, he knows the damn thing isn't venting right anyway.
Building department tried to reject the unvented configuration on violating my roof warranty. I told them they had no jurisdiction over my warranty and that was the end of it. I sprayed and life went on. It has been approved and everybody is happy.
My foamer has a letter from Elk corporation that warrants shingles over his foam (Demilic - Sealection 500). He says Elk has discovered that shingles actually last longer over unvented foamed roofs because of thermal mass. It keeps the shingles from rapidly expanding and contracting during sudden temp changes (thunderstorm during the hot summer, etc.). So if it works for Elk you know it works for everybody, just the other guys haven't done the study. So whatever, piss on the roof shingle warranty. If it was really a problem, then ask them how they can put the same shingle in Maine and Florida and Las Vegas? An unvented roof in Florida is cooler than a vented roof in Las Vegas. So where's the problem? There isn't one. Just more of the building industry dragging their feet. If these people ran the computer industry we would still be milling around trying to figure out how to plug in the PDP-11.
If I had it to do again I would use Elk and have a warranty. But I'm not lossing any sleep over it. Sorry for the rant, just a rant kind of day I guess!
MERC.
" If it was really a problem, then ask them how they can put the same shingle in Maine and Florida and Las Vegas? "Actually they don't.If you look at the catalog sheets you will see that only certain models are available in certain parts of the country.
That my be true in some circumstances, but I imagine that the vast majority of "regular" shingles are available everywhere. I'm sure mine are (GAF Timberline Ultra)
I think I saw on the GAF website that certain Timberline are only available in the NE, probably to produce some classic NE architectural look, rather than being a performance issue.
MERC.
Most national manufacturers do vary their line region-to-region, based on both weather conditions and style. In our area they sell shingles more resistant to algae staining, eg. And shingles here don't have to survive an Arizona summer, so high temperature resistance is rated lower than wind/ice/snow resistance.They probably also vary the warranty terms region-to-region, based on how they expect the product to hold up. (Not that a shingle warranty is worth the spit it takes to spit on it.)
Consumer Reports recently did an article on roofing. They generally get the story straight and didn't say anything about different regions. They rated shingles for wind, impact, algae, all that stuff. Did they drive around to different parts of the country. I doubt it, so either their ratings are crap or shingles aren't significantly different from one region to another (aside from architectural concerns).
MERC.
I had my roof deck sprayed this past summer underneath the roof deck in the attic. I used icycene foam. Looked like they used about 8-10 inches, worked out great, they even bridged over the 2X8's. Had to have them come back for some touchup spraying. I have a hip roof 3/12 pitch, the wall dimensions are 36' square and consequently the foamers weren't able to get into the corners from inside the attic. When I had the sofit removed (another project) you could see all the coverage they missed. They came back and resprayed the corners from the outside. I'll try to attach pictures later.
My question is this: had my first snow fall approx. 15" (Erie, PA) and I thought I wouldn't be ever see icles again-but to my dismay there are quite alot. What gives? Does it have to do with my low pitch? I do have those fancy "LeafGuard" gutters with intrigrated top shield, so that may be a factor. I don't know, any thoughts??
Thanks, Biff
First snow already? Wow, here in NC we hit 22 last night and I already can't wait for the dogwoods to start blooming in March!
I wouldn't be too dismayed about the icycles. Since you sprayed unvented, your roof has significant thermal mass. So sure you are melting some snow, probably mainly from solar gain into the roof deck and less so from conductive heat loss. How big are your soffits? I assume the roof deck that overhangs the exterior wall is not sprayed? It wouldn't matter anyway.
I also have leafgaurd (love those things) and I get icycles too. But you know an open top gutter just has ice in it, instead of hanging down. Seriously, I wouldn't worry about it and just sit inside your draft-free home and enjoy it!
BTW, I know that spraying foam into the soffit area of a low pitched roof is a problem. Once that Icynene hits and expands, there isn't a second shot at it. Seems like they would have a long nozzle or something that would help the reach. I guess the foam would have to stay two parts all the way to the end though since the nozzle would clog quickly. Glad they could come back and hit from the other side. I have dormers on my house and they are stepped back from the first floor wall by 15". I was wondering how to insulate that stepped back area. The foam guy just shot the stuff up in there a few times and it eventually came billowing back out into the soffit area. I was happy, looked good.
I'd love to see some pictures if you can.
MERC.
Merc,
Thanks for your insight, its sounds logical. The whole foam insulation thing is a little like black magic, I quess it hasn't been around that long in the U.S. for enough technical info. I was so sold on this foam stuff that after I had the underneath of the roof deck done I had them come back and insulate my walls in a way I thought of. I'm into a siding, sofit project so I'm thinking while I have the vertical aluminum siding off I may as well try to better insulate. I was thinking of blowin cellulose but came up with this: I cut the bottom one foot of all the sheeting on the first and second floors of the house horizontally. After I pulled off all the sheeting, I tugged the 1.5" of fiberglass batts down out of each stud cavity-worked like a charm because they were not stapled in. Then I drill up from the one foot opening in each stud cavity a one inch hole every 18"-24". The foam installer then sprayed the icycene foam up the cavity-which usually expanded about 2.5' up. Then to fill the rest he sprayed each of the 1" hole up the stud cavity. The outside sheeting 3/8 plywood bowed out but as soon as the foam stopped expanding it went right back to normal usually 10-15 seconds, it worked great only because I think of two factors. First the outside sheeting on the home is 3/8" thick which flexed outward when the foam expanded- bowed the sheeting in each stud cavity (16") approx. 3/4" out. Secondly the interior walls are plaster that has 3/8" wall board and 3/4" veneer plaster over the wall board- quite thick. But it worked out great no cracked plaster. In one stud cavity my wife was watching the interior walls and said she saw one time that the plaster "flexed" and she saw micro crackes but now nothing visible! Its amazing what it has done for this house (multi-level 1966 built). It is so quite in here now, not drafty and has reduced the gas usage by at least 60%. Oh by the way I had to take all liability off the foamer if it cracked the plaster. Incredible stuff!!
How do you post pics?
Biff
Post a pic-
While writing your post, look at the buttons below. "Attach Files". Gives you a new window with a few other buttons. One is "Browse", click that, find the picture you want to upload. Then click "Upload". Let the picture upload. You don't get a status indicator or anything, just wait until your filename appears below the heading at the top of the window. Continue uploading all the pics you want using 1,2. Then click Done (button #3).
BTW, people will get very upset if you post high res pictures (dial up users don't like it). Check out http://www.irfanview.com for a free picture viewer you can use to resize your pictures. I usually go to 800x600 which seems to keep the pictures small enough for dial up and big enough to keep some detail.
MERC
Biff,Are you crazy! Putting regular spray foam in a closed wall. You're lucky you didn't blow out a wall.I have 2 words for you - S L O W R I S E.Mike K
Amateur Home Remodeler in Aurora, Illinois
Mike,
I know I was in uncharted scrary territory, but when you think about it- is what I describe closed cavity? It is closed on three sides with multiple 1" relief holes in the cavity. I wish I would have take a movie of it when it was happening, pretty wild looking, but now with 1/2 iscyo board on outside of sheeting- 15 degrees outside is barely noticable! My heating requirements have gone down by 60%-so now I quess my boiler is way oversized. The input is 175,000 btu/output of 144,000 btu (@82.5% eff.) I don't think I'll gain anything going to a smaller boiler, especially since this one is only 10 years old- a Weil McKein. But your right Mike I am crazy, I could have made a big mess and alot more work for myself...but I lucked out!
Greetings Biff,
http://forums.taunton.com/tp-breaktime/messages?msg=24441.1
is an old thread here on Breaktime that includes a lot of data on posting pics and the Irfanview download.
Dialup patrons of the forum cannot download real large files or will take excessive time.
Two things are necessary to assist the dialups with your photos. Making sure that the set file association is set to jpgs if you are using the Irfanview system.
The other is to keep the KB picture size to preferably 50 to 75 KBs or at least under 100KBs.
How'd you like to start downloading a pic only to go get a cup of coffee, heat it up, come back and find the file is only half done downloading just to see a pic?
One other thing to ease the postings here is to break up the post into smaller paragraghs for easier viewing.
One large paragraph of sentences makes it harder to disect the info from.
Separate smaller paragraphs makes it easier on the eyes and the viewers won't have the tendency to just bypass your post if you are looking to receive particular information.
Cheers
Edited 8/22/2006 5:55 pm ET by rez
Biff
We used corbond 2# foam in our roof with a 6/12 pitch. We still get some icycicles mostly due to solar melting. The same time icycicles are forming on our roof, major ice dams are forming on neighbors homes insulated with conventional fiberglass. We have not experienced any significant ice damming, this can be attributed to our foam roof.
>We still get some icycicles mostly due to solar melting.That's the point. Melting isn't just from inside. I can have a snowcap on my dome and icicles at edges just because the sun will start to melt it.