Attic Gable End Wall Has A Lot of Flex

[Nick Ostrowski]

I was in the attic of my inspection yesterday when I saw moisture staining on the wall sheathing in the attic beneath the gable vent. I moved closer to it and when I braced my hand against the wall, I could feel the entire wall flex. So I tested the wall to see how much flex it had under hand pressure, and by shaking it with one hand, it probably had about 1.5 - 2 inches of back-and-forth play. It did this a few times and the buyer and realtor in the bedroom beneath said they could feel the entire floor shaking. There wasn't any drywall damage in the bedroom but it seems something should be done to stabilize the wall. The pic I took of the gable wall in the attic didn't come out well but you can see the way the 2x4 studs are oriented that it is contributing to the amount of flex the wall has.

I'm not recommending how to fix it but I'm wondering for my own knowledge what would be an appropriate fix in this situation.

[Jerry Peck]

Nick,

How tall were those gable end studs?

The first, and simplest, solution is to recommend adding "L" bracing to those existing gable end studs, i.e., nail a 2x4 or 2x6 to the side of those studs with the new bracing creating an "L" with the original stud.

If it moves that much just with your hand moving it, think how much it may move with the higher wind winter/summer storms you get - if you get winter or summer storms with 60 mph or so winds, I would recommend it be repaired.

The next thing to do would be to add diagonal bracing from (depending on how tall those gable end studs are) either at the mid-points or at the third-points in height, nailing those diagonal braces to the new bracing and to a rat-run brace on the top of the bottom chords.

Those are two easy and quick fixes for that. However, if you have higher winds, then the repairs to brace the wall become more complex.

I wouldn't let that go without recommending at least a minimum type of bracing repair. Heck, even tying those gable end wall studs back to the diagonal webs of at least the first 3-4 trusses would help keep that wall from moving like that.

[Garry Sorrells]

If the 2x4s are on the flat then the it will flex. Adding blocking will stiffen up the wall. If you were to add blocking with a 2x4 running the width of the house (90 deg to vertical) done in two locations the wall would be stiff.

If the 2x4s had been not on the flat simple blocking would be all that would be needed to stiffen up the wall.

[Nick Ostrowski]

Oh, I'm definitely recommending that it be repaired. I just wanted to let it be known I wasn't looking for a possible fix to put in the report.

That wall was approximately 10'+ high at the point above the gable vent. The 2x4s being installed flat is definitely what is making the wall so flexible. And I was making it move with one hand. It didn't take too much effort. I advised the buyer the same thing in regard to high winds when we get a nor'easter or remnants of a hurricane rolling through the area that the wall will flex.

Thanks for the feedback guys.

[John Kogel]

Bevel plank siding would have made that gable stiff enough. Plank sheathing, or plywood sheathing would have made it stiffer. It is just a bad combination of weak framing and weak sheathing material and you didn't tell us what the siding is. Vinyl?

It can be stiffened up but the tricky part now is getting long framing members up thru the hatch. Access is a big deal in an attic or crawlspace repair. The 2X4's may have to come in thru a soffit or a hole in the gable. Which could add to the cost and skills required.

[Dom D'Agostino]

I don't see any gable end bracing, although there may be something under the insulation.

[Nick Ostrowski]

Vinyl insulation on the exterior wall. It is a bad combination of materials and framing The materials in and of themselves would be fine with the proper framing and bracing. And the part about how to get the 2x4s into the attic is a good point. I think they have enough wiggle room but it is a factor to consider in regard to cost.

[Jerry Peck]

I don't see any gable end bracing, although there may be something under the insulation.

That diagonal bracing would not strengthen the tall studs from moving like they did when Nick pushed on them.


And the part about how to get the 2x4s into the attic is a good point. I think they have enough wiggle room but it is a factor to consider in regard to cost.

That is an easy part as there are two simple ways to accomplish getting full-size lumber into the attic:
- remove a short section of fascia
- remove a short section of soffit or cut a long but narrow hole in the soffit
- either of the above will allow even 16 footers to be brought up into the attic, of course, once in the attic, 16 footers would be a challenge to handle and move around, but 8 foot should not be a problem.
- remove the gable vent as stick the lumber in that way
- going through the gable vent puts the boards in the direction you will be using them without having to turn them 90 degrees.

Just some easy options that do not raise the cost much.

[Dom D'Agostino]

Jerry:

I stated that I didn't see any bracing, not just diagonal.

The FEMA PDF is just for folks not familiar with gable bracing of any kind, unlike our home State.

[Raymond Wand]

There has been a lot of leakage via the gable vent or bad siding. Perhaps there is also mould beneath the insulation.

[Jerry Peck]

I stated that I didn't see any bracing, not just diagonal.

The FEMA PDF is just for folks not familiar with gable bracing of any kind, unlike our home State.

Dom,

Right, that is why I wanted to make sure those who live outside of Florida understand that there is more to bracing gable ends than just that 'X' bracing shown, especially with a tall gable end and tall studs oriented flat-wise.

[paul hardy]

The second picture looks like a truss system for the framing and that end wall would be part of that system using a stantard gable truss, the bracing for that gable truss should be part of the engineering of the truss roof system.

[paul hardy]

A good example would be on page 28 of this guide.

http://www.alpeng.com/images/stories/pdfs/BGT_BOOK.pdf

[Jerry Peck]

Example of gable end retrofit bracing:
- http://www.coastalcontractor.net/pdf/2008/0805/0805gabl.pdf
- http://www.ihrc.fiu.edu/lwer/docs/Year%209_Section4_GableEndBracing_RCMP08-09.pdf

These are suitable to be installed without engineering, engineers may (and do) design different and simpler to install (at the time of construction) gable end bracing.