Detail at top of non load-bearing wall

[hokie66]

Would like advice on detail at top of reinforced concrete masonry wall. Wall is non load bearing. Gap at top of wall allows for deflection of slab above. Connection to slab required to brace wall out of plane. Gap and connection must be fire protected. Have used a few different details, but all have constructability issues. Would appreciate knowing what detail others use.

 

[JAE]

We've used two angles, screwed or welded to the underside of the metal deck above, with the appropriate gap for deflection. I don't know how this meets any fire-resistant condition, though.

The angles are usually about 8" long and spaced at 8 feet on center unless there are intersecting walls, which substitute for the angles.

 

[youngstructural]

My preference is to use a small angle running along one side of the wall, with anchors into the bond beam on one side through slotted holes in the angle. Fireproofing is by drywall boxing or running angle on both faces and coating the steel with intumescent paint. I have omitted the bolting to the bond beam in cases when I have specified continuous angles on both faces; There just isn't a need to connect further.

It's a reliable and easy to built detail. Cheap from a labour end of things, if slightly material expensive. I was taught the detail by an "old hand" at one of the offices I worked in and have found it to be simple and reliable, without any constructability issues.

Let us know what you choose to do,
Good luck,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...

 

[youngstructural]

You beat me out with (essentially) the same reply JAE!

The fire rating requirement is why I did not suggest staggering the angles, which is of course quite possible for strength, but may or may not satisfy your fire (depending on your code requirements and whether or not blast design is a further sub-requirement of your fire criteria).

Good luck,

YS

B.Eng (Carleton)
Working in New Zealand, thinking of my snow covered home...

 

[hokie66]

Thanks guys. I have used that type detail many times, but never have liked it, mostly due to the unreliability of builders in filling the top courses, as it is not a pleasant job.

The fire rating can be achieved, provided the building official will accept it, by firespraying the angles if they are on both sides, or by fire rated sealants if the anticipated joint closure is not too large.

Another approach I have recently heard described is to provide vertical dowels, into dowel caps inserted into the slab above, with space above the top of the dowel to accommodate the movement. I like the sound of this detail because of the ability to extend the dowel down into the second course. But it also sounds like a lot of work and probably requires a proprietary dowel cap to make the idea work properly.

 

[archeng59]

I have used the angles as described by JAE. Also, I've used the Heckmann masonry wall stabilizing anchor, which is a 3/8" diameter x 6" long steel rod welded to a steel plate. The rod is inserted into a plastic sleeve embedded into the CMU.

 

[jike]

Where fire rating is required or where the Architect would prefer not to see the angles, we would use Heckmann Wall Stabilizing Anchors. We would use a fire rated caulk in the top joint.

http://www.heckmannbuildingprods.com/PDF/Cat21.pdf

 

[hokie66]

Thanks archeng and jike. The idea is same as one I am considering, except I was going to do it upside down. But in my case, I need something more robust because the wall is 20' high and exterior in cylonic area. And don't think Heckmann is in Australia anyway.

Thanks all for your advice.