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Any thoughts on 1/2" closed cell & fiberglass Post New Topic | Post Reply

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Barry Wallett Posted: Jan 26, 2007 02:36 PM	Any thoughts on 1/2" closed cell & fiberglass Hello foamers, I have been reading your board faithfully for about 3 month's now and I read the archive posts. I wish I could have gone to Florida to meet all of you since it is almost like I know you based upon your comments. Here is my situation. I am building a home and would like closed cell through out, but the initial costs involved ruin my budget. I can have only fiberglass installed for about $4900. I can have 1/2" of closed cell spray foam and insulation installed for $7900. Total spray foam for $21,000. I would appreciate your comments on the foam and fiberglass combination since I would be able to afford the foam/fiberglass but not the total foam! For discussion sake the house is a colonial w/porch approx 2700 sq ft. Also I am in Connecticut if any one sprays in my area.
Posted: Jan 26, 2007 03:34 PM	Did the foam contractor happen to mention how many board fit his estimate was based on? The 1/2" seems a little odd. You need 2" to meet a vapor barrier requirement. Most estimates are 3.5" in the walls and 5.5" in the ceilings to meet code. Those figures don't add up to me. Tim Granite State Spray Foam Co.
Barry Wallett Posted: Jan 26, 2007 04:16 PM	The contractor did not note the board feet, they listed the area's to be insulated ie Main ceiling, Garage ceiling, 1st floor blockers, etc... I find the 1/2 curious also. The contractor supplied me with a brochure from Guardian building products - fiberglass insulation. The title is "two great products... One state-of-the-art insulation system" Inside the brochure details that the foam brand is Handi foam and the fiberglass batt is guardian. The brochure states the 1/2" is not a vapor retarder... Maybe this is a way to sell fiberglass and give the consumer a good feeling that they are getting the benefits of foam?
SprayFoamSupply.com Posted: Jan 26, 2007 08:18 PM	Handi foam is a diy yourself kit foam, it is not a commercial setup like most of the guys here spray. You should be able to get a bett price from one of us. George
Glenn Gamblin Posted: Jan 27, 2007 09:51 AM	Kick that idiot to the curb and check your area for foam applicators. Most houses I do that are that size are less than $7000. On this website open cell foam is bashed really bad, but it is an excellent product. I have been using it for years and have never heard a negative comment. Sure, it does absorb moisture, but it dries out very quickly and mold is not an issue. If you are opposed to it, have at least 2 inches of closed cell sprayed on the exterior walls and spray 5 1/2 inches of open cell in the attic to save money. You can get on the sealection500.com website and they will find a local contractor for you.
Barry Wallett Posted: Jan 27, 2007 02:36 PM	Thanks Glenn, I will definitely go to that website. 7k for foam is do-able!
Trey Gibson Posted: Jan 27, 2007 07:34 PM	$21,000? If that is the going rate up there then I am on my way. Are you going for a closed attic assembly or just spraying the walls. I wouldn't settle for 1/2" of foam. Do a minimum of 2" closed cell.
Gary Galloway Posted: Jan 27, 2007 11:14 PM	I think the reasoning for the 1/2 inch is to get the air tight seal and then insulate with the fiberglass. It is about 20 percent better than fiberglass alone but is no where near as good as closed cell foam.
Posted: Jan 28, 2007 01:29 AM	i do alot of the building envelope applications.. ie: 3/4" - 1" to the perimeter sides to seal,,,followed with either open cell,,,bibbs glass,,glassbatts or other product to obtain design spec rvalues,,, i apply in a cold climate area,,so i intentionaly shoot to the 1" or shorter with the closed cell to avoid a vapor retarder on the cold side of the wall...(we recommend some sort of a vapor retarder on the warm side of the wall with this system in our climate) in some instances we detail seal any joined frameing members with caulk includeing top and bottom plates,,,as well as foam windows and doors,,, we seal the drywall lid and any penetrations from the atticside with ~3" open cell and blow glass or cell over the top to r49 total... box sills, band joists, truss heels and perimeter top plate is sealed to r19,,,subfloors to r25 (4" closed cell, 8" open cell)minimum... these structures are tight,,and perform well,,,ie: the r15 of glass behind the foam doesnt loose its performance value in adverse conditions,,, the added performance of foam,,,,with a minimal upgrade to overall insulation system cost...foam good... consider the real costs of foam systems,,, you get what you pay for... i have a home wiht 3000 sq ft,, geo thermal, radiant floor heat with r19 sides and heels closed cell,,,glass attic lids,,,heating for $90/mth tops.. ever.. after 3 winters in east iowa... i have open cell homes that heat for 1/3 of design estimates,,,the insulation system makes the hvac systems work to design specs,,even under "extreme operating conditions"...(which is about 6 months a year here in the cornfield) the savings in energy each month exceeds the additional cost to the mortgage for the upgrade... foam smart...
Gerry Wagoner Posted: Jan 28, 2007 02:47 PM	Hello Barry: The cost for closed cell at 21000 seems disproportionally high. Rigid foam is normally 3 times the cost of fiberglass and twice the cost of cellulose wall-spray. As to initial costs, you can invest in your own home or invest in the local utility company. It's your choice. .5' of foam will allow condensation in the wall at certain times. I would wholeheartedly recommend rigid foam in the walls and half-pound in the attic envelopes. Half of our 4500 ft² house is cellulose and the other half is rigid foam. Guess which half is more comfortable? You guessed it. By a margin! Don't short yourself on insulation, pardner. You only get one chance to do it right, and that is when theose walls are open. We receive 4-6 calls per month from people who have fiberglass in their walls and they are dissatisfied with it, and want to upgrade to something better. They're out of luck. They are stuck with their crummy fiberglass (unless they are willing to remove the wallboard & fiberglass so we can foam it right). A handful of people have opted to tear the fiberglass out. best of luck, olger (foam better)
Posted: Jan 28, 2007 07:23 PM	Barry We have fiberglas guys in our area trying to market that system as well. And that foam is a box kit that doesnt require the specialized equipment or knowledge to install. You are obviously looking for a quality install. Make sure the foam is going to be installed by a professional foam applicator. Such as the guys on this forum. We do 1" foam,fiber packages with good results. There is no substitute for an all spray system but budgets do not always allow, and that is a good cost effective option. just remember that there are a number of energy mortgages that will allow you to upgrade,giving you more available funding. With a foam upgrade the increased amount in your mortgage will never exceed the savings in your utilities.So you arent really spending any more on the spf in the end.
Richard Russell Posted: Jan 29, 2007 11:09 AM	As noted, a thin (0.5") layer of closed-cell next to the sheathing can result in condensation under some circumstances. This would be in a heating climate, with cold outside temperature, rather than in a cooling climate. Condensation at the foam is less likely to occur if there is a good vapor retarder on the inside, installed properly and with no penetrations that allow convective transport of water vapor into the wall cavity. In general, a vapor retarder should be placed no more than 1/3 the way across the total R of the wall (in the direction of warm to cold). I've never seen on this forum any discussion of how to calculate intermediate temperatures within an insulated wall. It is actually rather simple. At steady state, the temperature drop across any layer of the wall, as a fraction of the total temperature drop across the whole wall, is that layer's R divided by the total R of the wall. As an example, take 0.5" OSB (R=1/inch), then 0.5" CC at R6/inch (aged) plus 5.0" FG at R3.2/inch, for a total R=19.5 (ignoring the drywall). The temp drop across the FG will be 16/19.5= 0.82. If the temp just inside the drywall is 65 and outside is 5(Fahrenheit), then the temperature at the inner surface of the foam will be 65 -(65-5)*0.82 or 16 F. Without a vapor retarder on the inside, so that interior moisture can diffuse readily through the wall cavity, 40% RH air inside likely will result in condensation within the FG layer and certainly at the foam surface. Also, with so great a temperature difference across the FG batt, there still would be the same problem of small density-driven thermal currents within the FG batt that renders it a relatively poor choice for a cold climate. It would seem that if a good VR, properly installed, on the inside is not assured, then any foam against the sheathing ought to take much more of the total temperature drop. If poly is used, then one has to ask if having too little CC foam just on the outside is a good idea, since there would be two vapor barriers, with the possibility of trapped moisture. If the purpose of a thinner foam layer on the outside is for air sealing rather than to provide a lot of R value, then wouldn't a more permeable open-cell foam be better for that purpose? Of course, one could argue that once on site to do any OC foam at all it would be better to do the whole wall cavity with the foam and skip the FG altogether. Any thoughts on the above?
Gerry Wagoner Posted: Jan 31, 2007 07:57 AM	Looping.
Eric Boyd Posted: Feb 01, 2007 04:03 AM	Im moving to Connecticut if thats the going rate for foam.Dont sell yourself short on the insulation.In our area 5000sq.ft.homes that we have sprayed with foam in july/august 120.00 -150.00 light bills same size bat house levelized at 350.00 minimum.
Posted: Feb 01, 2007 07:45 PM	closed cell at 1" or less is not vapor retarding membrane...i purposly apply to seal,,,not insulate,,,so as to not create a vapor retarding membrane on the cold side of the wall the concept of the building envelope is to seal the structure so the traditional insulation product performs better...ie: doesnt loose effective rvalue under adverse conditions(when we need the thermal performance the most)...i shoot in the 3/4" range on the wide open sidewalls,...(it is not a foam insulation system) condensation that occurs will manifest it self on the next "hard" surface towards the cold side of the wall in a cold climate area... so if there is foam in the wall,,,yes this is where the condensation will occur at the foam to fiberglass interface...if there is not foam in the wall the condensation will occur on the osb sheating/glass interface... i recommend to my customers a vapor retarder on the warm side of the wall in my cold climate area with a <2" closed cell application,,,i recomend a vapor barrier over fiberglass, cellulose, open cell at any sidewall depth...in my cold climate area... there is no perfect system,,,and the wall is able to dry to the exterior,... darned tootin that a vapor barrier on both sides of a wall is bad do-do... yes an open cell would work too...but the profile is less conducive to a batt followup...the bibbs systems work great with it...as it accomadates the profile... absolutely the foam systems,,,open or closed will out perform the hybrid/glass system,,,, its all about the additional cost of the foam systems... its all about keeping the trigger pulled....
Mike Glace Posted: Feb 01, 2007 11:56 PM	Hey was the company that gave you a estimate Eastern Insulation with offices in New Jersey cause they advertise that same style system with the closed cell and fiberglass on there website. Its called the ATS system the airtight system. I was checking it out the other night.
Barry Wallett Posted: Feb 02, 2007 07:30 AM	The company marketing the insulation system mentioned above is US insulation Corp out of Berlin CT. The salesperson there was really helpful. But, it really looks like they are not foamers, why else would they pitch their using a "do it yourself" foam system? From a marketing standpoint it would allow them to say "we have foam available too". If the customer doesn't go to a site like this they wouldn't know it was apples and oranges being compared. The end result would be you would get fiberglass.
Jesse Michalski Posted: Nov 07, 2013 08:48 PM	Unfortunately, for most homeowners, it comes down to the price. I am of the opinion that utilizing foam whenever you can is going to benefit you, even if you have to do only the walls, and vent and blow the attic. I have put some combination packages together for some people this year and they have worked quite well. They aren't as good as a whole house foam job, but it's better than a whole house fiberglass job and it's something people can afford.
Matthew Gowin Posted: Nov 02, 2014 02:51 PM	When I got all of my estimates they provided only a thickness and price. No board foot info. I had to measure and do the math myself. One contractor tried to stick it to me at $2.50 to $3 a board foot (I forget the exact) as well as telling me his 2lb foam was R7.5. I was really pissed after that and almost kicked the whole industry to the curb. I made a few statements that were not really warranted but it only takes one bad apple.
mark moyer Posted: Nov 03, 2014 10:16 PM	..what he said..