Coating on TJI

[Ken Amelin]

All the joists were coated with a high gloss type finish, almost an epoxy look to it. Does anyone know what this might be?

[Mark Reinmiller]

Probably an intumescent coating. Some codes require covering engineered joists, using a fire sprinkler system, or a coating to reduce the risk of collapse in the event a fire occurs.

[Dwight Doane]

Actually it looks like there is a coating on the side - covered by the insulation , any chance you pulled some insulation and took a picture

[dbsaia]

All the joists were coated with a high gloss type finish, almost an epoxy look to it. Does anyone know what this might be?

Looks like an intumescent paint as suggested by Mark. From a fire-protection perspective it makes little sense to coat the sides of the members and not the bottom, plus that engineered limber (or solid lumber) will last longer in a fire than steel bar joists, which tend to twist and sag when they get hot.

Could also be a spray-applied vapor barrier separating the conditioned upstairs from the basement or crawl space (?).

David

[Ken Amelin]

The coating was on all the joists. The insulation had a vapor barrier, so I don't think it was that.

[Ben Jacks]

The coating was on all the joists. The insulation had a vapor barrier, so I don't think it was that.

What you probably saw was a TJI FLAK JACKET by WEYERHAEUSER joist mfr for fire rated protection. The i joist span increase is improved to meet structure burn safety qualifications in single and multi family construction. rbj1

[Mark Reinmiller]

That may be it. I was not aware that this was offered from the factory. See image below.

31961