Insulation Sprayed On Underside Of Roof Deck

[BOCK FOLKEN]

I am working on an FHA appraisal on a home built in 2007 and this is a first for me.

The subject home is "super-insulated", using foam blocks with poured concrete in the center of the wall. I have experience with that. No problemo. Fairly common application.

The problem is the wood framed truss with a wood roof deck has been sprayed with some kind of foam. This is the only attic insulation installed. I have concerns how to treat this as I have never seen this before.

What say you? Thanks in advance.

 

[Walter Kirk]

What is your problem? If it meets code, and I would assume that 2007 construction meets the latest code, its fine.

 

[Mr Rex]

FYI: (2nd paragraph)

http://www.sprayfoam.com/spps/ahpg.cfm?spgid=66

 

[Mike Plumlee]

Just my personal opinion after listening to several building experts - spray foam on the roof decking is a waste and a completely inferior product to traditional radiant barrier. As done, the foam works to keep heat in the attic - not out by reflecting the radiation. No insulation on the attic floor? Oh my. Someone got sold a bill of goods. Finding any adjustment for this will be very difficult.

 

[Terrel L. Shields]

foam on the roof decking is a waste and a completely inferior product to traditional radiant barrier.

As for "Pink Panther" insulation. It is an utter waste of money and time. Useless...worse than useless. R factors are a real joke... It is Thermal Mass that counts. I'd knock the bottoms out of styrofoam cups and make insulation out of them before I'd ever use rolled fiberglas bats.

Foam works fine and works as well as "conventional" radiant barriers, but it might not be correctly done.... And Cellose would be a better option. Why?

Foam won't leak. What if the roof leaks? You will never know it. So when you need to take up the roofing, you might find the decking has rotted. I would never do foam in a house but OTOH, I would always do that on a full metal building like a light (black iron) steel shed .

 

[Cigar]

As a builder I can tell you that this is a very complicated area for an appraiser, first you have to find the brand of the product, then it's ES Report number, for instance here is one, ESR 2917, there are usually requirements for ignition barriers, like being encapsulated by sheetrock or covered by an intumescent paint. Some of these products emit formaldehyde gas and are a health concern, others like Icynene don't but require an ignition barrier.

 

[BOCK FOLKEN]

As a builder I can tell you that this is a very complicated area for an appraiser, first you have to find the brand of the product, then it's ES Report number, for instance here is one, ESR 2917, there are usually requirements for ignition barriers, like being encapsulated by sheetrock or covered by an intumescent paint. Some of these products emit formaldehyde gas and are a health concern, others like Icynene don't but require an ignition barrier.

There is clearly no ignition barrier in this application. The attic appears to be completely sealed with the stuff.

Per Walter Kirk's comment, the installation would appear to meet the building code in this jurisdiction, assuming it was inspected and passed and given a C.O. I do not intend to investigate all the prior code inspections for the property but I will if I have to.

I did read somewhere that the stuff has a tendency to give off noxious smoke when burned.
Would you include something like this in your FHA report? A lot of things give off noxious fumes when burned (carpet?).

This gives me a little bit of heartburn mostly because it is new and different.

 

[Mr Rex]

Most do not require an ignition barrier in single family residential construction. Think of it this way, the foam is in the same location as the roof sheathing and framing, how is it more susceptible to fire than these wood members? Also some of the foams are treated with fire retardant additives.

 

[Allan Edwards]

Just my personal opinion after listening to several building experts - spray foam on the roof decking is a waste and a completely inferior product to traditional radiant barrier. As done, the foam works to keep heat in the attic - not out by reflecting the radiation. No insulation on the attic floor? Oh my. Someone got sold a bill of goods. Finding any adjustment for this will be very difficult.

Mike

As a local builder in Houston, I'm curious which building experts are telling you that spray foam is a waste. I'm hearing just the opposite. And in our climate radiant barrier does help some, but you still have HVAC equipment and ducts in a very hot attic as opposed to running foam up to the ridge, having a non-vented attic. The houses I've built this way are giving very good results from homeowners regarding utility bills and comfort. We are also able to downsize the tonnage on the AC's.

Allan

 

[Mike Plumlee]

Mike

As a local builder in Houston, I'm curious which building experts are telling you that spray foam is a waste. I'm hearing just the opposite. And in our climate radiant barrier does help some, but you still have HVAC equipment and ducts in a very hot attic as opposed to running foam up to the ridge, having a non-vented attic. The houses I've built this way are giving very good results from homeowners regarding utility bills and comfort. We are also able to downsize the tonnage on the AC's.

Allan

Allan - I have done a lot of new construction appraisals and been in many attics around town (77019, 77024, 77005, 77382) and I have never seen a new home with foam insulation the way it's pictured here on the underside of the roof. 100% of the homes I go into have Tyvek or after-market radiant paint. Three of the builders I talked to this summer (for my own personal reasons) didn't have the same opinion as yours, but I don't doubt your word on your success.

The most popular method of achieving success is a radiant barrier on the roof, plenty of soffit-ridge vent air circulation and blown-in fiberglass on the attic floors. Radiant heat is coming into the attic regardless. A radiant barrier will probably stop about 60-70% - and that remaining heat has to be able to transfer up and out by airflow, whether it's a natural flow or forced.

I retrofitted my 1979 home with both radiant paint and then radiant shield foil on the roof and about 18 inches of fiberglass on the floor. Added probably 50 soffits (1 story 3800sf). That reduces my energy consumption by about 40-50% alone.

If foam will do that and provide energy savings, excellent. I just have never seen a home with the foam product here in Houston (retrofit or new). And I've never run into a builder that suggested foam over a barrier. I'm sure there are some, just never met em.