Masonry Wall - Connecting new 8" cmu wall to existing 8" cmu wall 1

[shuff213]

I have a project involving a one story, steel framed building with exterior 8" block walls (single wythe, no veneer). Open web roof joists frame to interior columns and beams, and bear on the exterior block walls on the northern and southern face of the building (joists run from north to south).

A portion of the building will be demolished and removed, and a new 8" cmu wall will be installed at the southern face of the building. This wall will be the new exterior wall, and support existing roof joists (which will be cut and reinforced per the demolition process).

Does anyone have any suggestions/advice/lessons from experience for connecting this new block wall to the existing block wall (anchors to use, useful products, things to watch for)? The two walls will connect at the building corners.

I'm planning to reinforce the new cmu wall at 24" on center, but I'm unaware of the reinforcement in the existing block walls to remain (no existing drawings available).

Thank you for any feedback you can provide.

 

[hawkaz]

Put control joints in at those locations

 

[southard2]

Without more info I completely agree with hawkaz. Its easy to do and you won't have to worry about differential settlement issues with new footing settlement.

John Southard, M.S., P.E.

http://www.pdhlibrary.com/

 

[Den32]

Yes, control joints are probably best solution to keep the two walls separated.

If you want to connect them together, use pieces of steel angle with epoxy anchors drilled into the CMU cells. the angle would need to have long enough legs to get anchors away from edges of CMU (say L8x8).

Another thing: you said you "don't know if the existing CMU walls are reinfored" - based on the description of work, the IBC Existing Building Chapter may require you to analyze the existing structure for compliance with current codes. If that is the case, you will need to justify how the existing CMU walls to remain work (for cladding loads, and maybe even as shearwalls if that is the Lateral Force Resisting System).