2009 IRC anchor bolts

[Daddy-0-]

In Virginia we are about to start the 2009 next month. The question has come up about the new anchor bolt wording where the bolts must be solid grouted int CMU cells. We have assumed this would mean 6" or 8" CMU's and no more installations bolts in the annular space between brick and block. We just received an interpretation that would suggest that bolts grouted into a 4" CMU cell would meet the requirement. For those of you already in the 2009 what are you allowing and what are you seeing? Opinions please!!!! I don't like where this is going already.

 

[rshuey]

Most of the anchor bolt instructions are, the bolt must be 1 1/2" from both side faces and 4-1/2 inches from the end face to center of the bolt. Can't do that with 4" cmu's.

 

[rshuey]

http://www.strongtie.com/products/connectors/SSTB.asp

 

[Daddy-0-]

Gang... I need to bring this up one more time to try to get some more responses. The plan reviewer is now accepting plans for brick veneer with anchor bolts set into 4" CMU. I cannot find instructions for regular "L" shaped bolts. Does anyone have a link or any thoughts on the subject? The one link provided is for Simpson anchors which are not being used here.

How are they being installed in your areas? Thanks.

 

[ICE]

We don't see much of that here except at the top of parapet walls for a nailer and never less than 6" CMU. What is the application that would allow 4" CMU?

 

[Daddy-0-]

This is for the situation where you have brick veneer for a crawl space foundation and the veneer stops at the mudsill. They used to use 4" block inside with brick outside and the anchor bolt would be grouted between the two. The new language is making them install the bolt INTO the CMU. My issue is that a 4" CMU does not give enough concrete coverage on the edge of the bolt. We are getting plan submittals with this design but we can't find a code section to not allow this. I think the intent was to mandate 6" CMU but the language left just enough wiggle room.

 

[KZQuixote]

This is for the situation where you have brick veneer for a crawl space foundation and the veneer stops at the mudsill. They used to use 4" block inside with brick outside and the anchor bolt would be grouted between the two. The new language is making them install the bolt INTO the CMU. My issue is that a 4" CMU does not give enough concrete coverage on the edge of the bolt. We are getting plan submittals with this design but we can't find a code section to not allow this. I think the intent was to mandate 6" CMU but the language left just enough wiggle room.

Got to agree. Never heard of a 4" wall.

Bill

 

[imhotep]

This is for the situation where you have brick veneer for a crawl space foundation and the veneer stops at the mudsill. They used to use 4" block inside with brick outside and the anchor bolt would be grouted between the two. The new language is making them install the bolt INTO the CMU. My issue is that a 4" CMU does not give enough concrete coverage on the edge of the bolt. We are getting plan submittals with this design but we can't find a code section to not allow this. I think the intent was to mandate 6" CMU but the language left just enough wiggle room.

So I presume the CMU acts as the foundation wall supporting the floor, wall and roof loads. Perhaps take a look at 2009 IRC R404.1.1 Design of masonry foundation walls. I don't see where 4" CMU is an option.

 

[Daddy-0-]

Will look up that section on Monday when I have a code book handy. Thanks.

 

[imhotep]

Will look up that section on Monday when I have a code book handy. Thanks.

Don't forget the ICC online library.

http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_4_sec004_par001.htm

 

[Paul Sweet]

Daddy-o, are you referring to IRC R403.1.6? Have you had any luck on the VBCOA website?

For others, this is typical crawl space construction in central Virginia - 8" block below grade with 4" brick over 4" block above grade. The collar joint should be filled solid with mortar to bond the brick & block together.

One (labor-intensive) possibility is to cut the outside face off the block where the anchor bolts will be located, then grout them in after the brick is laid. This will give you about 2-1/2" width for the grout.

 

[KZQuixote]

For others, this is typical crawl space construction in central Virginia - 8" block below grade with 4" brick over 4" block above grade. The collar joint should be filled solid with mortar to bond the brick & block together.

Hi Paul,

Do the masons use any sort of K Web so that the two wythes can be considered an 8" wall? I used to see that in Maryland and Virginia when I was inspecting there.

Bill

 

[mtlogcabin]

They used to use 4" block inside with brick outside and the anchor bolt would be grouted between the two

That does not sound like it would offer much hold down or lateral resistance at all.

this is typical crawl space construction in central Virginia - 8" block below grade with 4" brick over 4" block above grade

The IRC does not address this type of wall. It specifies an 8" block with a wood wall and 4" brick veneer. I suggest your jurisdiction require an engineer design this one.

 

[benny]

That does not sound like it would offer much hold down or lateral resistance at all. The IRC does not address this type of wall. It specifies an 8" block with a wood wall and 4" brick veneer. I suggest your jurisdiction require an engineer design this one.

I agree with mtlogcabin on this one; doesn't meet the prescriptive code.

 

[Sifu]

The type of foundation you describe is what I saw (and built) for years in North Carolina. I recently brought it up to a BIA engineer in the context of the veneer being a bearing element. I was under the false (now I know) that the 4" and brick made an 8" bearing foundation wall. He set me straight. The veneer, bonded or not is not load bearing therefore you would only have a 4" cmu for bearing. If thats all you have for bearing then I can't see an anchor bolt working in it.