Multi-Wythe Brick Wall

[Francis Vineyard]

Can Table 1805.5(1) 2006 IBC be used with multi-wythe clay brick foundation walls?

Don’t have access to the ASTM listed in 2103.2

Trying to determine if this type of foundation is outside the scope for unbalance backfill and require an engineer. Plans show the existing wall as plain concrete.

As always thanks for the answers

 

[Paul Sweet]

Multi-wythe brick walls should be at least as strong as hollow block walls of the same thickness. Where the table requires solid block, a brick wall should be 2 wythes thick with the space between wythes grouted solid.

Brick Industry of America Tech Note 9A has a lot of information on ASTM requirements for bricks. http://www.gobrick.com/TechnicalNotes/tabid/7658/Default.aspx

Is your avatar photo from Goshen Pass?

 

[Francis Vineyard]

Thanks Paul

That’s a beautiful ride, when I used to fish Bratton’s Run and Pad’s Creek. My Avatar is the front of my property. Full of spooky Browns protected by Daces that hook my fly’s.

 

[Paul Sweet]

I realized that I left out the words "properly bonded". How the wythes are bonded together has a major impact on the lateral loads a brick wall can withstand. English Bond or Dutch Cross-Bond are the strongest. A wall built with one of these bonds should be as strong as a solid block wall. Flemish Bond is close behind. A Common Bond foundation wall should have a header course every 4th course, and I'd consider it as having the strength of a hollow wall. Above grade every 6th course is adequate. BIA Tech Note 30 gives more information on bond patterns.

IBC 2109 gives requirements for empirical design, and table 2109.5.3.1 gives thicknesses for masonry walls. I don't know why the code has 2 tables for (almost) the same thing.

However, if they want to build a 2-wythe wall with insulation between wythes then engineering is required if there's more than a couple feet of unbalanced fill.

You've got a great front yard!

 

[Francis Vineyard]

This is an existing wall 12" thick built in 1928, though difficult to see from the photo but there is a slab across the front that is opened below. Plans call to backfill this area with 57 and form a new slab. Though this wall on the right side of the photo is backfilled all the way across with a paved drive. Wall height is 9' 4"

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