Wood in non combustible construction?

[JPohling]

I have a client that is requesting that we replicate a heavy timber post and beam element as a focal point at a reception area in a Type 1 high rise. See photo.

If we could somehow get members this large into the building, does anyone believe we can install a small portion of heavy timber in a Type 1 building? I do not.

I will be proposing a built up assembly of non combustible materials sheathed in a wood veneer look alike.

 

[mark handler]

Non-Bearing? Decorative?

 

[JPohling]

Non-Bearing? Decorative?

Mark, Yes purely decorative and only self supporting

 

[mtlogcabin]

Mark, Yes purely decorative and only self supporting

2018 IBC
SECTION 603
COMBUSTIBLE MATERIAL IN TYPES I AND II CONSTRUCTION
Exceptions:
19. Heavy timber as permitted by Note c to Table 601 and Sections 602.4.3 and 705.2.3.1.
601 note c
c. In all occupancies, heavy timber complying with Section 2304.11 shall be allowed where a 1-hour or less fire-resistance rating is required.

 

[JPohling]

So Heavy Timber elements could be used in a Type 1 structure based upon the above references that are also within the California Building code. I guess I am a little leery that they can be used as an "interior finish" rather than an actual structural element. This is purely cosmetic in nature.

 

[JPohling]

There is also an exception for heavy timber CBC 803.3 That would seem to allow them to be used as an interior finish with the exception of various exit components. But I am not convinced that these exceptions actually apply if the decorative element that we are proposing is sized accordingly and looks just like a heavy timber post and beam condition except it actually is just a prop and serves no structural use. Thoughts?

 

[mtlogcabin]

Foam or real wood? your choice
https://www.foamdesigncenter.com/fauxwoodbeams.aspx

 

[Yikes]

So Heavy Timber elements could be used in a Type 1 structure based upon the above references that are also within the California Building code. I guess I am a little leery that they can be used as an "interior finish" rather than an actual structural element. This is purely cosmetic in nature.

CBC 801.1 includes in its description "decorative materials", and under this section, the only thing you would need to worry about is flame spread, and even then heavy timber is excluded from this per 803.3.

I assume that what is making you leery is the potential "fuel load" of the heavy timber faux structure. In practice, due to the protective charring layer the heavy timber is probably less of a fuel load than (for example) an extremely large wood conference table in a type 1 building.

 

[mark handler]

Mark, Yes purely decorative and only self supporting

I would have no issues with it

 

[JPohling]

Thanks all! requesting info on the foam products and their code compliance. California company, so perhaps. Prefer the wood.

 

[steveray]

Trim is trim....Conference table is a great example....