# Roof shingle loading



## Pcinspector1 (Aug 12, 2011)

Is there anything in the code about loading roofs with shingles for extended periods of time. Just wonder'n

All I could find is R907.2

pc1


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## Mark K (Aug 12, 2011)

It would depend on how much the shingles weight and how long.  Look at Table 2.3.2 in the NDS.  It assumes construction loads are there for up to 7 days.  If the loads are equal to the design snow loads it is assumed that they are not there form more than two months.  An engineer may be able to justify longer durations.  This assumes that the loads on the roof do not significantly exceed the roof live or snow loads


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## ICE (Aug 13, 2011)

Pcinspector1 said:
			
		

> Is there anything in the code about loading roofs with shingles for extended periods of time. Just wonder'nAll I could find is R907.2
> 
> pc1


Well I don't know about the rest of you but the shingles have been on my roof for 12 years and nothing bad has happened so far.


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## Francis Vineyard (Aug 13, 2011)

As Mark K invited here's the same information from a truss designer;

Asphalt shingles maximum stack height limited to 2 bundles for 1 week unless alternative information is provided by the Building Designer, Truss Designer or Truss Manufacturer. 

http://www.trussec.com/handling.html

http://www.sbcindustry.com/images/publication_images/b4.pdf


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## RJJ (Aug 15, 2011)

I agree with the seven day as stated by Mark.  I assume you are referring to chimney stacks for extended periods of time?


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## brudgers (Aug 15, 2011)

Pcinspector1 said:
			
		

> Is there anything in the code about loading roofs with shingles for extended periods of time. Just wonder'n  All I could find is R907.2  pc1


  Yes, it's the 20 psf live load.  That's why it is so high.


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## Mac (Aug 15, 2011)

Concentrated loads like stacks of plywood and shingles have led to failures of roof systems a few times.


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## Frank (Aug 15, 2011)

Floors get overloaded as well

In a neighboring jurisdiction they were loading the drywall into a building put too much in one spot and the building collapsed with one fatality--inadequate construction bracing was also a factor.

I found one where they had loaded the black sprinkler piping through the window into a large pile on the 4th floor saw 6-8 inch floor deflections with busted truss members below.  I eased away from that part of the building.


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## RJJ (Aug 15, 2011)

Mac it sure has and it needs to be distributed.


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## Mark K (Aug 15, 2011)

The code required live load on sloped roofs can be as low as 12 psf.   On some old roofs the actual capacity may be less.  This is probably consistent with the truss designers of two bundle thicknesses.


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## brudgers (Aug 16, 2011)

Mac said:
			
		

> Concentrated loads like stacks of plywood and shingles have led to failures of roof systems a few times.


   A stack of plywood would usually correlate with an incomplete roof system - and both correlate with construction loads which are not governed by the building code (except in the case of reroofing and that's what the 20lbs LL covers). Loads during construction would be covered by worklplace safety laws and regulations.


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## Mac (Aug 16, 2011)

3301.2 Storage and placement. Construction equipment and materials shall be stored and placed so as not to endanger the public, the workers or adjoining property for the duration of the construction project.


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