Fireproofing to existing steel beam 1

[ajk1]

There is some fireproofing to an existing steel beam in an old building, that has been damaged that needs local repairs. The fireproofing appears to me a metal lath and plaster. I see such an assembly in my old (1998) ULC catalogue, for a column (Design No. Z400)but I have not been able so far to find it for a steel beam. Would anyone know which UL or ULC Design No. this would be?

 

[Ingenuity]

ajk1,

UL have differing design numbers for Beams, based upon 'floor-ceiling' (Group N) and 'roof-ceiling' (Group S) designations.

UL numbering system here: Link

I did a quick UL Canada database search and there were no results. See Link

But UL.com (USA based) had 4 designs (N401 to N404) for 'floor-ceiling', as follows: Link

But, you need to check on the flooring system to make sure you comply because in Design N403, for example (see photo below) the 1-5/8" is called out as "2. Steel Floor and Form Units* — 1-5/8 in. deep cellular and fluted types, welded to beam.".

And for beams of 'roof-ceiling' type there are zero metal lathe assemblies as far as I could tell.

The ULC Design Z400 that you mentioned is by Specialty Vermiculite Corp from Canada. It may be worth giving them a call to see if they have a beam assembly that meets UL or ULC.

 

[ajk1]

To Ingenuity - that is precisely the information that I was seeking and you have done a thorough job responding to my question. Very much appreciated. I will give Specialty Vermiculite Corp a call. Thanks.

 

[ajk1]

The contractor to-date has done some small patching of this assembly with what appears to be a construction grout. I don't imagine that would be acceptable, would it?

 

[Ingenuity]

You are welcome.

I think that it is prudent to do patch repairs to the existing/damaged fire proofing system using new constituent materials of similar make-up, so in this case stay with vemiculite plaster rather than Portland cement patches.

 

[ajk1]

ok, thanks again.