Roof 'Eyebrow" at brick gable end 4

[NFExp]

I am looking for any ideas for attaching the lower roof element ("eyebrow") at a brick gable end.

I have attached a detail as a reference. I feel that there should be a typical detail for this condition but I was unable to find one. In the detail we show the brick continuous thru the "eyebrow" because we are trying to avoid a steel lintel.

FYI, this is for a residential project in a 130mph wind zone and seismic D.

 

[JAE]

You could count on the brick veneer to take vertical load for something like this - but the horizontal loads from the eyebrow eccentricity I would want to take back into the wood structure and bypass the brick in any way possible.

The top of the eyebrow could have bolts extending through to a beefed up stud system in the attic area. Likewise solid blocking between brick and stud might be considered but this would require careful detailing to avoid moisture migration through the brick and onto the wood.

 

[Structcon]

Never put structural load on veneer! With that said, if your drawing is to scale, the vertical load is insignificant in comparison to the veneer and the OOP load is just slightly more. But, look at uplift due to wind and how to transfer the moment? Show 2 horizontal steel angles aligned with top and bottom of the eyebrow and tie thru for T/C. Brace angles back to trusses.

 

[dhengr]

NFExp:
Many building officials interpret the code’s wording ‘brick veneer should not carry any loads other than self weight and lateral wind and EQ’ quite strictly. I would make the argument that the vert. load added is very small in total, the brick veneer can tolerate that. But, the eccentricity of that roof, and those out of plane loads must be carried through the brick, not loading the brick, in tension and compression, and back into the wood structure. Is this roof just 10' long, over a bay window or sliding doors, or is it full length of the end of the bldg? Be sure that the brick veneer is on a good brick ledge.

I would leave a few bricks out every 4' or so, behind this little roof structure so you can get back to the stud wall and the truss system. At the top of the roof surface I would certainly have a cont. flashing, and a cont. counter flashing which was caulked back into the next highest brick joint, which had been raked back. If you could adjust the soffit elev. a bit, you might cantilever a 2x6 or 2x8 over the bot. chord of the gable truss, every 4' or so and back into the bldg. a few truss spaces. These would carry all of the roof loads when connected to the rough fascia 2x, without imparting any out of plane loading. Maybe wrap the 2x lookouts at the brick with some ice and water guard mat’l. or some such so there is no contact btwn. the two.

 

[Ron]

Agree with Structcon that you don't want to load the veneer if you can help it. Check Ch. 14 of the IBC or Chap. 14 of the FBC and you will see that it is not allowed.

Now to the practical. You will end up bearing somewhere on the veneer unless you sleeve completely through it. Even then, you might still bear on it slightly.

I have done similar with aluminum canopy frames hanging off the side of buildings. Have done these in S. Florida with high wind loads. In those we provided a sleeve that was U-bolted to the studs, extended through the brick veneer and had a bearing plate on the outside face of the brick that was slightly isolated from the brick by sealant. Keep the sleeve modular to correspond to the brick coursing.

You can then bolt your eyebrow to the bearing plates that, through the sleeve, will transfer the load back to the studs, bypassing the brick veneer. Works fine, just make sure you have a good waterproofing detail around the sleeve. I would make the sleeve 1" smaller than the brick hole (brick hole should be 1/2 of a brick. Use backer rod and sealant around the sleeve to isolate from the brick. Use backer rod and sealant around the bearing plate to isolate from the brick.

 

[JAE]

Brick veneer isn't that feeble and weak, folks. This is a very small wood framed eyebrow.

I wouldn't put a floor or major roof on veneer of course. But anything you do here in an attempt to bypass the veneer and attach to a frame behind for vertical loads will be hard to do without bearing on the brick in any case.

Brick veneer would end up taking more vertical load with a brick angle lintel over a large opening compared to the loading involved in this particular case.

 

[ToadJones]

In my nail bender days when we had little eyebrows we'd sometimes just bolt them to the brick...usually just on birds nest returns

On ones that spanned the whole gable end, we did something like what dhengr is saying and installed what we called frieze blocks (not really what a frieze block or board is, but we were just dumb carpenters) every few feet that were attached back to the wood structure. They were as thick as the brick and the brick was laid around these blocks....same thing for deck attachments. If the head flashing on the eyebrow is done properly, the frieze blocks should be weather tight.
I've never "designed" what I talking about here...just seat of the pants....

 

[ToadJones]

If your case here, you can actually extend this block back a truss or two extra and just cantilever it out the few inches to get out to the brick face.
I'm assuming this can all be done with wood and lags.

Dhengr probably has the best idea from a strength standpoint with cantilevering some boards that would tie into the tops of the bottom chords of the trusses.....it would be just like installing your rat-runs vertically and running them out a few extra inches.

Tying into gable trusses sucks anyway. Gable trusses are junk and are usually warped. I prefer a balloon framed wall. Makes for a nice continuous straight flat gable end.

 

[hokie66]

Think about what might happen in the future when you do something like this. Can someone come along and attach an awning to the fascia of the "eyebrow"? Or worse yet, decide that since you can hang the eyebrow roof off the brick, you should be able to hang a basketball backboard similarly? Too many kids are killed by collapsing gable brickwork. I would want to build the eyebrow with the roof structure, stop the veneer below, and use a different type cladding above. Better for watertightness, as well.

 

[JAE]

hokie - yes - a different material above would be a good suggestion to the designer/owner.

 

[Ron]

JAE..agree that brick isn't that feeble, but 130 mph wind load, with reversal, isn't either. When you have an eyebrow without much depth, top to bottom, the rotation on the brick can be considerable.

 

[NFExp]

Thanks for the responses.

I think I am going to detail something along the lines of what ToadJones and dhengr was saying.

 

[ToadJones]

If you do go with brick above the eyebrow, I'd seriously consider balloon framing the gable end wall. The gable will be much stiffer than a flimsy gable truss. I used to balloon frame the wall to the "drop gable" height and then just nail the drop-gable truss to the inside of the wall basically just for a nailer.

If you do use a balloon framed wall, be sure you install the proper fire blocking if required by your code.

 

[SkiisAndBikes]

As the eyebrow is relatively small, I would consider bolting it directly to the brick, with the following modifications.

If the brick veneer has not yet been installed, I would have them install additional brick ties between the masonry and the backup structure, in the vicinity of the bolts. If the brick veneer has already been installed, I would consider installing a series of stainless steel Helifix ties between the masonry and the backup structure. In both cases, it would be beneficial to have a more robust backup structure than a gable end truss.

 

[JAE]

Ron - agreed. That's why I mentioned above to only use the veneer for vertical gravity and take out any lateral forces back into the main frame of the building.

My biggest worry on a detail like this is if you use wood framing to tie back into the main frame. Any wood embedded in brick veneer gives me the willies.

 

[Ron]

JAE...same here. I use aluminum or steel tube to transfer the loads back to the structure.