1x4 let in brace

[Richard W. Washington]

What are your opinions on the wind strapping being used to repair the 1x4 let in that was damaged? I know it is not going to be per plan but just wondered to what degree of structural integrity it offered? Thanks.

[Brian A. MacNeish]

Originally Posted by rwashington

What are your opinions on the wind strapping being used to repair the 1x4 let in that was damaged? I know it is not going to be per plan but just wondered to what degree of structural integrity it offered? Thanks.

If of sufficient gauge and width, nailed as require by code, it should be alright. These braces act in tension only. When the interiior drywall is added it will gain much more structural strength!! but in the meantime.........

What scares me is with the building at this stage of construction, I don't see any other temporary bracing.....and there appears to be no panel wood sheathing on the exterior!! What is the white material we are seeing on the exterior.....insulation? If so, this house may be be waiting for a good strong wind to become a pile of sticks!!!

[Kenton H. Shepard, CMI]

If that is a strap, it's no good and should be called as a defect. Metal diagonal shear braces are made just for that situation, and are common in many parts of the country, but they are "T" shaped in cross section and so will work both in tension and compression. A flat strap is definitely a defect.

I see a couple of other diagonal braces installed.

[Brian A. MacNeish]

Originally Posted by kshepard

If that is a strap, it's no good and should be called as a defect. Metal diagonal shear braces are made just for that situation, and are common in many parts of the country, but they are "T" shaped in cross section and so will work both in tension and compression. A flat strap is definitely a defect.
I've never thought of the t-brace as having much strength in compression....but I could be wrong!

Guess it depends on who you talk to. From a Readers Digest article Building Rock-Solid Exterior Walls:
"Metal braces (Fig. D) nailed diagonally across studs and plates help counteract racking. You’re most likely to find them in homes less than 25 years old. They may be T-shaped, L-shaped or flat. Metal braces are strong under tension (when forces are trying to, in effect, stretch them lengthwise), but are weak in compression (such forces can actually kink, buckle and weaken the brace). Metal braces are therefore strongest installed in a “V” or “X” pattern. That way, no matter which direction force comes from, one wall brace will be in tension to help prevent racking."

I see a couple of other diagonal braces installed.

1x4" diagonal braces have little strength in compression......... but overall there is little racking strength in this home as I see it through one picture and especially if there is no interior 2x4" temporary bracing and no exterior structural sheathing.

I have seen collapses of a 3 story apartment building (partially built but with roof and wall plywood sheathing in place and interior partitions framed) as well as 2 bungalows with insulation sheathing and code approved t-braces. All building met code inspections ......but will not stand up to wind forces when partially built.......you'd be surprised how much 1/2" drywall ties all walls together and strengthens the frame!!

[Brian A. MacNeish]

http://www.umass.edu/bmatwt/publications/articles/bracing_foam_sheathed_walls.html

[Barry Adair]

location, location, location
let the "engineer of record" sign off on any and all modificaations
http://www.tdi.state.tx.us/wind/index.html

[David P. Valley]

Originally Posted by badair

location, location, location
let the "engineer of record" sign off on any and all modificaations
http://www.tdi.state.tx.us/wind/index.html

I concur 100%.

Please (stay out of trouble) and don't go calling out questionable defects when you're not absolutely sure if this was designed that way. Unless of course you are a structural engineer from that jurisdiction.

If I were to locate a questionable structural defect, I'd simply recommend a structural engineer to evaluate area of concern.

[Richard W. Washington]

This is typical construction practice here. Dow Styrofoam Blue Board and Dow Board Structural Sheathing (white board with red lettering). At frame stage 2 no temporary bracing is needed. Maybe its a location thing but its not done around here. IN fact, if the builder (Newmark) was that concerned about it, especially with Hurricane Gustav, then I'm sure they would have put some up.

Originally Posted by Brian A. MacNeish

If of sufficient gauge and width, nailed as require by code, it should be alright. These braces act in tension only. When the interiior drywall is added it will gain much more structural strength!! but in the meantime.........

What scares me is with the building at this stage of construction, I don't see any other temporary bracing.....and there appears to be no panel wood sheathing on the exterior!! What is the white material we are seeing on the exterior.....insulation? If so, this house may be be waiting for a good strong wind to become a pile of sticks!!!

[Richard W. Washington]

thanks for the map Barry. That is helpful info.

However this home was in Katy which is not in a wind storm or designated cat. area. It is just W of Houston on the way to San Antonio.

If I get a gig in Galveston, Jefferson, Chambers or Matagorda county, which I don't expect to due to price, my drive will be at least 75 miles one way and the fee is going to begin at $550.

Originally Posted by badair

location, location, location
let the "engineer of record" sign off on any and all modificaations
http://www.tdi.state.tx.us/wind/index.html

[Richard W. Washington]

Yes, I agree the flat strap was a defect.

The two diagonal braces are additional 1x4 let in braces which are correct.

Originally Posted by kshepard

If that is a strap, it's no good and should be called as a defect. Metal diagonal shear braces are made just for that situation, and are common in many parts of the country, but they are "T" shaped in cross section and so will work both in tension and compression. A flat strap is definitely a defect.

I see a couple of other diagonal braces installed.

[Kenton H. Shepard, CMI]

I was thinking of the 1 1/2" flat straps that come in coils. Racking in one direction it's fine, the strap won't stretch, but racking in the other direction, a flat strap would buckle easily. True, I'm not an engineer. Carpenter for a long time, but never an engineer.
And anyway, any idiot knows that brace would be strongest in compraction. I mean tensition. I try to use the middle digit portion of my brain when searching for the right term in order to more clearly see to the root of the matter.

Hope that helps.

[Marcel R. Cyr]

I think Kenton and Barry are both on the same and right track.

Addittional info;

http://www.strongtie.com/news/indust...ventional.html

Section R602.10.3 provides eight different methods which can be used as braced wall panels. The installation requirements and limitations for each method are described in the IRC. The minimum length of each method is described below. The panels are placed at each end of the wall line (or within 12'-6" for wind zones, and 8'-0" for seismic zones from the end). The panels are spaced no more than 25 feet on center and not less than a certain percentage of that wall line. The areas of the wall between the braced wall panels can be sheathed with any type of sheathing material.
Braced wall panel methods

1. 1x4 let-in diagonal bracing or approved metal strap devices such as Simpson RCWB and WB/WBC Wall Bracing products (minimum length of 4'-8" for a 8 ft plate height, 5'-3" for a 9 ft, and 5'-10" for a 10 ft)
2. 5/8" thick diagonal wood boards (minimum length of 4 ft)
3. Wood structural panel sheathing (minimum length of 4 ft)
4. Structural fiberboard sheathing (minimum length of 4 ft)
5. Gypsum board with fasteners at 7"o.c. (minimum length of 8 ft for single or 4 ft for double sided wall)
6. Particleboard wall sheathing panels (minimum length of 4 ft)
7. Portland cement plaster (minimum length of 4 ft)
8. Hardboard panel siding (minimum length of 4ft)

Additional attention is brought to Section R602.10.10 and R602.10.11 of the IRC.

Hope this helps.

Marcel

[Brian A. MacNeish]

Something that was suggested but not asked:

Has the AHJ inspected and signed off or has a structural PE approved the fix?

and/or

With the Dow SIS system being properly installed and meeting code requirements, the diagonal bracing may be redundant (I know it would be in my area). It may be a moot point.

[Brian A. MacNeish]

Originally Posted by kshepard

I was thinking of the 1 1/2" flat straps that come in coils. Racking in one direction it's fine, the strap won't stretch, but racking in the other direction, a flat strap would buckle easily. True, I'm not an engineer. Carpenter for a long time, but never an engineer.
And anyway, any idiot knows that brace would be strongest in compraction. I mean tensition. I try to use the middle digit portion of my brain when searching for the right term in order to more clearly see to the root of the matter.

Hope that helps.

That's why they recommend intallling them in X or V configuration pairs. Or if they are installed on each end/corner of a wall (standard diagonal way), one or the other is always in tension, depending on wind direction, to resist racking.