Wood Supporting Concrete 3

[msquared48]

This subject has been discussed here before, probably beating a dead horse. Nevertheless...

Have a possible project where the client wants to build an earth home on a rock bench. He wants to use PT planks for the roof with sod over, all supported by Glulam Beams. I believe the code states that concrete cannot be supported by wood except under certain situations, such as lateral, but I am wondering on the logic here.

Asside from the huge size of beam that would be required, I am wondering if the problem is inherently in the wood to concrete contact, which could be alleviated with a metal cover bracket between the two.

Any thoughts here?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[BAretired]

I don't feel comfortable with wood supporting concrete, but it is done in some places. I have seen three story walk-up apartments framed with concrete slab floors supported on wood studs.

I don't know what your code states, but our code permits concrete to be supported on wood provided the fire rating is adequate for the occupancy affected.

BA

 

[MiketheEngineer]

I think the latest IBC allows that - not sure. But BOCA outlawed it based on the theory that fire would burn the wood supporting element and allow the concrete to fail. That's what I was told.

Both codes allowed lintels to be installed on wood members and support brick. What's the diff??

I just haven't had much reason to violate the rule - if it is still in the code.

 

[steve1]

http://www.structuremag.org/Archives/2006-4/D-CUPD-IBC-Wood-Framing.pdf

 

[msquared48]

Hmmm. OK. Well the idea is still creepy to me anyway.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[Brad805]

I agree it is not a great idea. I designed some precast slabs that sat on a timber wood frame that I did not design. I finally gave up arguing and designed my part. I'll never understand some people's idea where they think they need to save $$.

Brad