# Anchoring a roof to masonry walls



## jar546 (Jun 25, 2013)

When you have CMU walls such as a garage, how to you require the roof to be anchored?


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## ICE (Jun 25, 2013)

Anchor bolts and a 3x on the top of the wall.  Since it is an engineered solution, I wouldn't say that we "require" that.  I've just seen it many times.  Sometimes it's a 4x and as wide or wider than the cmu.

Sometimes it is a ledger and anchor bolts with straps set in the wall that are nailed to roof framing members.


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## jar546 (Jun 25, 2013)

There is a specific code section in the IRC that covers this prescriptively.  Often overlooked.


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## ICE (Jun 25, 2013)

jar546 said:
			
		

> There is a specific code section in the IRC that covers this prescriptively.  Often overlooked.[/quoteSorry about that.  I was thinking  (IBC) we almost never build residential with CMU.


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## jar546 (Jun 25, 2013)

Interesting.  72 views at this point and no substantial discussion or opinions.  I am a little surprised considering how vocal some of us are and how we debate and talk through things.


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## David Henderson (Jun 25, 2013)

Jar i've always seen anchor bolts place at the last grout pour. In calif. very rarely do you see block homes usually commercial


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## RJJ (Jun 25, 2013)

I need a code book and I am at Starbucks testing the take out counter approach!


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## RJJ (Jun 25, 2013)

OK back in the office. Section R606.9.2.1 2009 IRC

add to this section 606.11 (1) (2) (3)


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## jar546 (Jun 26, 2013)

PA has a lot of garages built out of CMU so it is relevant.  Just because someone does not normally see it, does not mean that they won't and hopefully will know the code that applies and the rules for attachment which are different than sill plate attachment for foundations which was my point but we don't have any takers.


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## mtlogcabin (Jun 26, 2013)

Never see CMU in residential construction probably due to our seismic zone it is not cost effective. We do see ICF 8" flat wall systems which are engineered.

When I left S Fl in 97 the common practice was an 8" wide by 16" or 20" tall poured tie beam with 4 #5 rebar around the top of the CMU wall, cells at 32" OC where installed with a #5 and grouted at the same time the tie beam was poured. Hurricane straps where placed in the tie beam prior to placing concrete.


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## RJJ (Jun 26, 2013)

Besides the section listed above you need to account for wall bracing adjustment factors. That is listed in R301.2.2.2.1


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## David Henderson (Jun 26, 2013)

When I start getting these types of buildings I will have to get fetched up on them. There are a lot of different types of attachments for CMU buildings. Just don't see these buildings, but on a rare occassion it happens. As I always say make it look like picture. You can study anything if is not put to practice you won't retain it. If you see them all the time you should already know the answer Jeff.


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## ICE (Jun 26, 2013)

David Henderson said:
			
		

> When I start getting these types of buildings I will have to get fetched up on them. There are a lot of different types of attachments for CMU buildings. Just don't see these buildings, but on a rare occassion it happens. As I always say make it look like picture. You can study anything if is not put to practice you won't retain it. If you see them all the time you should already know the answer Jeff.


Ya Jeff....what's up with that.


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