Thread: Cut Truss - who can verify repairs?

Hi Guys and gals!

I did an inspection last week and called out a couple of trusses that were cut in the attic. I mentioned that cut trusses should be repaired properly, and may have a engineer stamp on them (At least that is what I have read - I don't come across cut trusses - my first in 4 years)
Anywho, does anyone know of a contractor of company in the Phoenix area that can repair and/or verify a cut truss repair?

One of those learning experiences we all go through. The sellers agent is asking me how to verify that the repairs were done correctly, and I'd like to supply a few names. I mentioned a Structural Engineer, but the Realtor said "That is cost prohibitive". I felt like say, "hey, I'm not the guy that cut the trusses!"

Any help would be appreciated.
Thank you!
Thanks!

Originally Posted by Dave Hill

Hi Guys and gals!

I did an inspection last week and called out a couple of trusses that were cut in the attic. I mentioned that cut trusses should be repaired properly, and may have a engineer stamp on them (At least that is what I have read - I don't come across cut trusses - my first in 4 years)
Anywho, does anyone know of a contractor of company in the Phoenix area that can repair and/or verify a cut truss repair?

One of those learning experiences we all go through. The sellers agent is asking me how to verify that the repairs were done correctly, and I'd like to supply a few names. I mentioned a Structural Engineer, but the Realtor said "That is cost prohibitive". I felt like say, "hey, I'm not the guy that cut the trusses!"

Any help would be appreciated.
Thank you!
Thanks!

Hi Dave.
Check with R& K building supplies. R & K Building Supplies - Products & Services, Phoenix Building Materials
It looks like they have contractors that may be able to check it.

Duffy sent me a name of this company if it needs to be designed
Flipe Babbitt at Babbit/Nelson Engineering…602-430-1832

Dave,

We have 4+ truss companies in the Glendale/Peoria area. I refer buyers to them and tell them to call and ask for their service department.

From the buyer’s feedback that I have gotten, the truss company will send an engineer out to evaluate and design repairs if need be for around $200-$300. Then it cost another $200-$300 to have the truss company come out and do the repairs.

I often hear of the total cost being $500-$600 to have 1 or 2 trusses repaired.

You might want to look for a couple of trusses companies in your area to help with keeping the trip charges to a minimum.

Jeff
.

It SHOULD be a Structural Engineer or a qualified and certified truss designer who designs and certifies that repairs were made as directed. I recommend to people to: 1) Keep the certification as part of the property documentation like deed, mortgage papers, etc. 2) Place a copy in a zip-loc bag or seal plastic cover and staple it to a truss on or near the repair truss. In the future, an inspector who might see the repairs will see the certification and only needs to report that truss repairs and a repair certification were observed in the attic. Becomes a non-issue.

The big builders are often furnished with a book of common truss damage repair designs by their supplier(s). If the builder repairs the truss, it still should be certified that the repair meets or exceeds the repair design requirements, stamped and/or signed by the supplier's rep.

Originally Posted by Dave Hill

Hi Guys and gals!

I did an inspection last week and called out a couple of trusses that were cut in the attic. I mentioned that cut trusses should be repaired properly, and may have a engineer stamp on them (At least that is what I have read - I don't come across cut trusses - my first in 4 years)
Anywho, does anyone know of a contractor of company in the Phoenix area that can repair and/or verify a cut truss repair?

One of those learning experiences we all go through. The sellers agent is asking me how to verify that the repairs were done correctly, and I'd like to supply a few names. I mentioned a Structural Engineer, but the Realtor said "That is cost prohibitive". I felt like say, "hey, I'm not the guy that cut the trusses!"

Any help would be appreciated.
Thank you!
Thanks!

Tell the Realtor that the code requires truss repairs to be designed by an engineer or truss designer. Once you find an engineer familiar with truss repairs it is not a big deal. Very few contractors even come close to proper repairs, unless they have seen quite a few truss repair drawings.

Originally Posted by Mark Reinmiller

Tell the Realtor that the code requires truss repairs to be designed by an engineer or truss designer. Once you find an engineer familiar with truss repairs it is not a big deal. Very few contractors even come close to proper repairs, unless they have seen quite a few truss repair drawings.

I've seen a few of those. Some come pretty close but not enough. I usually can tell by the number and size of nails used to make a repair. Of course, there's the guys who nail a piece of 2x4 to the truss as a short doubler. The trouble is the project manager sends some carpenter up who probably can't read the detail instructions and he nails up a piece of plywood or OSB to the truss.

Originally Posted by Stuart Brooks

I've seen a few of those. Some come pretty close but not enough. I usually can tell by the number and size of nails used to make a repair. Of course, there's the guys who nail a piece of 2x4 to the truss as a short doubler. The trouble is the project manager sends some carpenter up who probably can't read the detail instructions and he nails up a piece of plywood or OSB to the truss.

Plywood or OSB gusset plates are a common repair for damaged truss joints. They work fine. OSB is better than plywood for this application. The nailing and the size of the gusset plates is where I see the most mistakes. It is not uncommon to need about 6 to 8 or even way more nails per member with 10d nails extending through both gusset plates and clinched. It can be twice as many or more when nailed from both sides. To get that many nails into a member the gusset plates can get quite large.

Originally Posted by Mark Reinmiller

Plywood or OSB gusset plates are a common repair for damaged truss joints. They work fine. OSB is better than plywood for this application. The nailing and the size of the gusset plates is where I see the most mistakes. It is not uncommon to need about 6 to 8 or even way more nails per member with 10d nails extending through both gusset plates and clinched. It can be twice as many or more when nailed from both sides. To get that many nails into a member the gusset plates can get quite large.

I'm curious.... could you elaborate on why OSB is favorable to plywood. I would have guessed the other way around.

As for the OP, I specify engineer or truss manufacturer to evaluate and make repairs. I've heard the "it's too expensive" argument also and my response is pretty much what you say. Send the bill to the guy with the saw

Originally Posted by Matt Fellman

I'm curious.... could you elaborate on why OSB is favorable to plywood. I would have guessed the other way around.

As for the OP, I specify engineer or truss manufacturer to evaluate and make repairs. I've heard the "it's too expensive" argument also and my response is pretty much what you say. Send the bill to the guy with the saw

OSB is better because it is considered denser most plywood and therefore nails have a higher capacity. Also, the shear strength is greater than plywood, which can be a factor is sizing the gusset plates.

When I see cut trusses, I tell them the repair needs to be designed by a structural engineer or a field rep for the manufacturer of the trusses. I'm sure most do not follow my recommendations because they want to save money.

Originally Posted by Mark Reinmiller

the shear strength is greater than plywood, which can be a factor is sizing the gusset plates.

It's my understanding (without looking it up) that the cross lamination of plywood makes for a stronger product than OSB. I'm quite sure I'm right about this.

Originally Posted by Eric Barker

It's my understanding (without looking it up) that the cross lamination of plywood makes for a stronger product than OSB. I'm quite sure I'm right about this.

Eric, As an example, looking at 23/32" or 3/4" OSB versus plywood, the shear strengths are 215 versus 96. The axial tensile strength of plywood is better is one orientation and worse in the other than OSB. The axial compressive strength of plywood is about 50 percent higher than OSB, but that is not too important for gusset plates.

The real advantage of the OSB is the strength of the nails. Looking at a 0.131 nail in a joint using an OSB gusset plate with a HEM-FIR chord or web, the capacity would be 83 pound versus 70 pounds. that is about 19 percent higher. Since gusset plate repairs usually need quite a few nails I try to do what I can to reduce the number of nails.

I recommend and prefer plywood for truss gussets....it is much stronger in the vertical position than osb. Try this test - Take a 1/2 piece of plywood and osb. Rip them down to 7" strips. Set your saw horses up 7' apart. Slam the osb on top the saw horses. It will break quite easily. Do the same thing with the plywood. It will not break no matter how hard you slam it. OSB seems to be stiffer however when laid across joists being used as subfloor. In that orientation plywood can be made to bend to fit almost a circle without breaking. Osb will snap.

Originally Posted by Ray Thornburg

I recommend and prefer plywood for truss gussets....it is much stronger in the vertical position than osb. Try this test - Take a 1/2 piece of plywood and osb. Rip them down to 7" strips. Set your saw horses up 7' apart. Slam the osb on top the saw horses. It will break quite easily. Do the same thing with the plywood. It will not break no matter how hard you slam it. OSB seems to be stiffer however when laid across joists being used as subfloor. In that orientation plywood can be made to bend to fit almost a circle without breaking. Osb will snap.

Regardless of you tests, there is published approved test data for both materials. As an engineer I need to use that data. I can't recommend using something based upon what I might think is better. A lot of people think deck screws are better than nails for structural use. They are wrong too.

Also, your experiment would basically test impact strength, which is not something a truss joint typically sees in service.

Originally Posted by Mark Reinmiller

Regardless of you tests, there is published approved test data for both materials. As an engineer I need to use that data. I can't recommend using something based upon what I might think is better. A lot of people think deck screws are better than nails for structural use. They are wrong too.

Also, your experiment would basically test impact strength, which is not something a truss joint typically sees in service.

You make a good point and I certainly I would not suggest someone go against unbiased independent test data especiallly when designing structural components. I believe both products are allowed to be used for similar purposes. It just make me uneasy to see a product used in a vertical application like that which snaps in half so easily (really easy). Try it ..... you'll see what I mean.

I also believe plywood is better for repairs,it is stronger overall and less likely to fail.