# Construction type IIA - Wood Shims for roof curb?



## PaulR (Sep 15, 2016)

I have a building that is construction type IIA and they want to use wood shims to level out some roof curbs. As far as combustible material is concerned, do these fall under the exception for wood blocking?

I'm using the 2012 Michigan building code.

At first it seemed like an obvious yes, but the more I re-read the section the more unsure I am. Perhaps I should stop re-reading it.....


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## steveray (Sep 15, 2016)

I would call it blocking....


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## mtlogcabin (Sep 15, 2016)

Use fire retardant wood and you should be okay


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## Yikes (Sep 16, 2016)

PaulR said:


> At first it seemed like an obvious yes, but the more I re-read the section the more unsure I am. Perhaps I should stop re-reading it.....


Can you reference us to the section you are reading?


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## PaulR (Sep 16, 2016)

Section 603.1 Allowable materials (Combustible) in type I and II construction. In particular number 16:

14. Blocking such as for handrails, millwork, cabinets
and window and door frames.


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## TheCommish (Sep 18, 2016)

it is out side of the building and part of the rubber roof most likely, so unless it is part of a rated assemble does not mater in my opinion


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## JBI (Sep 19, 2016)

PaulR said:


> Perhaps I should stop re-reading it.....



Yup.


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## ADAguy (Sep 19, 2016)

Yes but, are the curbs supporting HVAC equip? If so, fires have been found to start in them.


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## steveray (Sep 21, 2016)

ADAguy said:


> Yes but, are the curbs supporting HVAC equip? If so, fires have been found to start in them.



People are the #1 cause of fires....Maybe we should not allow them in the building.....?


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