Pipe Brace to TALL Masonry Parapet and steel bar joist 1

[Ben29]

I am designing a flex building with steel bar joist and CMU block bearing walls. The architect is showing very tall parapet walls above each storefront entrance. The parapet walls are about 24 ft long x 10ft tall.

I designed this pipe brace system (attached). I don't feel great about it because I feel like it will be expensive and it may leak. The roof slopes towards this parapet wall. I will have (3) braces per parapet wall - so braces will be spaced at ~ 10ft.

I am open to suggestions.

 

[phamENG]

Replace those with a light gauge studs at 16" on center on a 45 degree angle. Put channels or angles between the joists to pick them on the low end, and attach them to wall above. Sheath them with whatever you're allowed to based on building construction type and fire rating - plywood, fire treated ply, metal deck, whatever. Have the architect run the roofing up it and flash it to the masonry wall.

 

[haynewp]

Other options if they want the CMU look full height:

1. I would look at changing to 12" block and cantilevering the wall.

2. The kickers will put a large point load on the CMU and the joists under parapet wind. If I did kickers, I would run a continuous steel support along the backside of the wall to attach the kickers to. Put additional cross bracing in the roof to help with roof deflection.

 

[a2mfk]

Used to do LOTS of these types of storefront details, and agree with phamENG. Always did these out of lt gage steel framing. That gets you continuous diagonal bracaing, and also I would want to distribute that diagonal bracing load to every roof joist, not just 10 ft on center. Those reactions have to be pretty large, and you know those roof joists were not designed for that.

Also, I would use a continuous HSS at the top of the roof joists that runs parallel to the wall, and frame into this, which can spread out the load vertically and laterally into the roof diaphragm and joists. Eliminate the vertical member all together. Then you can just brace the joists for point loads with traditional joist bracing details.