Sprayed Attic Insulation Question

[Bite N Hold]

First of all I am new to the forum and it seems like a wealth of knowledge. We are under contract to buy a house. in the attic is sprayed Urethane(I assume) foam, with another layer of something else sprayed on top of that. This is over the entire roof deck and trusses where they attach to the roof deck. The second layer is light tan in color, brittle, and looks like concrete from the back side when removed. It also appears to have small fibrous strands in it. It is very light weight. I am not sure what it is. Any ideas? The house was built in 1978 and the foam is original with the house. Can this be some type of cellulose or is it more likely an asbestos type coating? Why would it be sprayed on top of the foam? Should I be worried?

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[Scottpat]

I have never seen anything like that with a second coat.

[Bill Kibbel]

It looks similar to some sprayed-on fireproofing applied to structural steel. It often consists of cement or gypsum mixed with a fibrous binder. The fibers are usually ceramic, mineral wool/rockwool or asbestos. I've never seen it in a residence.

[kurt]

That's what I was thinking. It's like a combination of different materials that aren't normally combined, with the closest similarity being the stuff they spray on parking garage or other large structures.

What would they be spraying in Stuart FL back in the 70's? Very strange.

[Bite N Hold]

Well, funny you should mention steel bldgs. The house was done by a guy that built large food processing plants. The guys that did one of the plants also did the house. So it very well could be what Bill is talking about.

[Scottpat]

Well, funny you should mention steel bldgs. The house was done by a guy that built large food processing plants. The guys that did one of the plants also did the house. So it very well could be what Bill is talking about.

Commercial freezer warehouses are built in a similar fashion. They use spray foam and with some I have seen use what looks like a second coat that sprayed on the exterior as a protective finish. It looks like a light weight concrete mix that is aerated to the point it almost looks like foam. It hardens and forms a protective shell over the foam.

[David Meiland]

Well, funny you should mention steel bldgs. The house was done by a guy that built large food processing plants. The guys that did one of the plants also did the house. So it very well could be what Bill is talking about.

I've seen situations where a commercial contractor or tradesman built a house and used stuff almost never used in residential but commonly used on his commercial jobs. That may be the situation there.

[Bite N Hold]

Just curious if it is safe for my little ones. The A/C blows into the attic and comes down through returns in the ceiling. There is no duct work. Did that stuff contain anything I need to worry about?

[John Kogel]

Just curious if it is safe for my little ones. The A/C blows into the attic and comes down through returns in the ceiling. There is no duct work. Did that stuff contain anything I need to worry about?

That is enough incentive to send those samples to a lab for testing.

Like Bill said, there could be asbestos in there as a binder.

Your AC will be more effective and easier to filter if you have some ducts installed.

[kurt]

Yeah, all those old system designs of using crawlspaces and attics as pressurized plenums for moving air....they all had issues with air quality and contamination.

I'd be checking that stuff.

[Bite N Hold]

Update. I sent it to the lab and it came back as cellulose ,fiberglass and binding agent. Thanks for all the help and info.

[Tom Breslawski]

Well, funny you should mention steel bldgs. The house was done by a guy that built large food processing plants. The guys that did one of the plants also did the house. So it very well could be what Bill is talking about.

Commercial freezer warehouses are built in a similar fashion. They use spray foam and with some I have seen use what looks like a second coat that sprayed on the exterior as a protective finish. It looks like a light weight concrete mix that is aerated to the point it almost looks like foam. It hardens and forms a protective shell over the foam.

This is exactly what it looks like. We have this inside a farm cold storage (circa 1986). The other cold storages all use traditional spray foam.

The only undesirable aspect of this material that we have experienced is that it washes away quickly when coming in contact with water. Ideally that would not happen in a residential attic.