Is airspace needed between stone veneer and OSB.

[jpoe7]

I am in western NC and working a detail to repair an arch below a porch that has suffered water damage. The arch has an inner frame work of OSB and a stone veneer finish. It doesn't look as though the original contractor placed enough water proofing over the OSB. Is an airspace needed for the repair or is waterproofing around the OSB enough to keep the OSB from rotting?

 

[msquared48]

Absolutely, and venting for the airspace too.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[woodman88]

I agree with msquared48.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[jpoe7]

Thanks a lot. Thats what I was thinking, but I had a contractor tell me other wise and I wanted some back up.

 

[woodman88]

Ask him for the code section or a product report that states the otherwise.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[msquared48]

When OSB gets wet, it becomes MUSHBOARD if left to not dry out. Not much structural value there.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[MiketheEngineer]

Yes - and "kill" the architect involved...

 

[dik]

Look up 'Rain Screen'... part of pressure equalisation to prevent moisture from penetrating building envelope.

Dik

 

[boo1]

Weather-resistant barrier must be used on all exterior and interior mortar applications except for those over masonry or concrete.

Look at ICC Acceptance Criteria 38 “Acceptance Criteria for Water Resistive Barriers.”

To maintain the weather-resistance of the exterior wall on which stone products are installed, rigid, corrosion-resistant flashing, weep screed and a means of drainage should be installed at all penetrations and terminations of the stone cladding. Flashing type and locations should be in accordance with the requirements of the applicable building code.

 

[Ron]

If the stone veneer is a "fake stone", then it is treated just like stucco...needs two barriers, no air space.

If it is a true stone veneer, then treat it like a brick veneer with air space and ties, with appropriate cavity wall waterproofing, through-wall flashing and weeps.

See Chapter 14 of the International Building Code (NC Building Code)

 

[focuseng]

Ron, I think you mean "Thin Stone Veneer (assemblies)" which can be true stone or "fake" stone. The application menthod and material weight is key to that point and not the composition of the material so much. The alternate is specified as "mortar placed stone (assemblies)".

______________
MAP

 

[Ron]

focuseng...you are correct. Thanks for the clarification that I did not provide!

 

[focuseng]

I always just refer to Thin stone veneer as "lick and stick" anyway.

______________
MAP