Broken Truss

[Roby Set]

I am about to buy a townhouse ( built in 2001) and got it inspected. The inspector found a broken truss in attic and recommended a review and remediation by a qualified engineer.

There was no other defects found in the attic. There was no sign of water leakage

Although I have asked the seller to fix it, can the experts in this forum provide their opinion on how serious is this kind of broken truss and how much should I be expecting to pay for fixing this should the seller decides to pay me instead of getting it done himself

I have uploaded a pic

Thanks,

Robbie

[Rick Cantrell]

WAG
$300 for the engineer and depending on what the engineer says $250-$500 for the contractor
.

[Jerry Peck]

WAG
$300 for the engineer and depending on what the engineer says $250-$500 for the contractor
.

I'd agree with that WAG ... and just to make sure he understands what we are saying ... Wild A$$ Guess ... because the costs vary so much from area to area and within areas.

Triple that WAG to provide a cushion ... and if the seller balks just tell the seller that he can pay for the licensed structural engineer and the contractor.

Keep in mind that there COULD BE other things that the structural engineer finds around that area which may have lead to that truss failing ... or it could be just that one truss web.

[JeffGHooper]

To understand how important it "could" be. A truss is one part of a truss system. When one fails, the truss on each side have to make up the load, which they are not designed to do. The entire system is dependent on each and every component doing its job. Failure of one truss can result in failure of the "system" depending on the dead, live, lateral, and moment loads.

Yea, it is kind of a big deal.

Sometimes to the point of, "catastrophic failure is eminent."

No WAG here. Manufactured trusses for a while.

[Jack Feldmann]

Saw this same post on another internet forum, with a photo. Its a web that is broken in two (likely at a knot).

[Jerry Peck]

Saw this same post on another internet forum, with a photo. Its a web that is broken in two (likely at a knot).

The photo is in the pdf file, and yes, it is broken in two and is at two knots.

[Mark Reinmiller]

Because of the location of the break it is a pretty easy fix. Around here the engineering would be more like $500. The work could be done for $250 if the contractor does not charge much for their labor. I would think about $1000 total, and that could be low, depending upon your location.

Regarding how serious it is, any damaged truss should be repaired. If they don't fix it, you may have to fix it for the next buyer. It could also cause local sagging in the roof, which could make the repair more expensive later.

[JeffGHooper]

Engineered trusses can only be #2 or better lumber for top, bottom and large webs, meaning no knots over 1 1/2" is size and MSR Lumber, (Machine stress rated). You have no way of knowing the severity of a web break, especially a large web from center, without engineering. In fact, such a break could be a sign of a truss design flaw, meaning the rest are bad too.

Absolutely needs engineering by the Truss Engineer of Record.

No way to estimate costs because the Engineer is not going to prescribe a repair until he knows "why" it broke. He is required as an Engineer to perform a rational analysis of the condition and the loads.

[Jerry Peck]

Engineered trusses can only be #2 or better lumber for top, bottom and large webs, meaning no knots over 1 1/2" is size and MSR Lumber, (Machine stress rated).

The truss manufacturing facilities also try - there is that word again - "try" to make sure that chords and webs do not have two knots together like that shown in the photo.

But, like I have said many times, we all make mistakes, and some mistakes lead to small and inexpensive fixes while other mistakes lead to more complex and costly fixes.

[Mark Reinmiller]

Engineered trusses can only be #2 or better lumber for top, bottom and large webs, meaning no knots over 1 1/2" is size and MSR Lumber, (Machine stress rated). You have no way of knowing the severity of a web break, especially a large web from center, without engineering. In fact, such a break could be a sign of a truss design flaw, meaning the rest are bad too.

Absolutely needs engineering by the Truss Engineer of Record.

No way to estimate costs because the Engineer is not going to prescribe a repair until he knows "why" it broke. He is required as an Engineer to perform a rational analysis of the condition and the loads.

Trusses often have relatively large knots (even #2 grade) and cracks or breaks at knots are common, especially with SYP, which is common used for trusses on the east coast. I design repairs for trusses quite often. The repair does not have to be performed by the "Truss Engineer of Record". When a house is many years old its hard to know who supplied the trusses. I design for the full strength of the member in tension or compression, or the approximately force in the member based upon the strength of connections. I can usually determine who made the truss plates and look of the design data for the plates.

[JeffGHooper]

Trusses often have relatively large knots (even #2 grade) and cracks or breaks at knots are common, especially with SYP, which is common used for trusses on the east coast. I design repairs for trusses quite often. The repair does not have to be performed by the "Truss Engineer of Record". When a house is many years old its hard to know who supplied the trusses. I design for the full strength of the member in tension or compression, or the approximately force in the member based upon the strength of connections. I can usually determine who made the truss plates and look of the design data for the plates.

Maximum knot size in #2 and better is 1 1/2". That is how it is graded, by knot size and grain tightness and a slue of other things. #2 and Better may not have combination knots. Does not mean one does not slip through every now and again. The National Grading Rule Committee (NGRC) was established to develop and maintain nomenclature and descriptions of grades for dimension lumber that conform to the Standards. Grading requirements are readily available.

Then you must be an Engineer, as they do require an Engineer.

[Marc M]

I repaired a 3 cut trusses in a house where someone cut them out for a whole house fan..engineering was $750, permits were $140 materials were $50

[John Kogel]

Trusses often have relatively large knots (even #2 grade) and cracks or breaks at knots are common, especially with SYP, which is common used for trusses on the east coast. I design repairs for trusses quite often.
Mark, that is interesting. We started building with manufactured trusses here about 1970 and they immediately became the standard. The preferred wood is Douglas fir, but of course now that has been modified to SPF. I have never seen a truss web pop like the one in that pic and can't remember ever finding trusses damaged by forces other than brain-dead humans with tools.

One thing I see in the newer homes is 2 X 3's for the webs. So the engineers have decided the older homes were over-built. ;)

[JeffGHooper]

Mark, that is interesting. We started building with manufactured trusses here about 1970 and they immediately became the standard. The preferred wood is Douglas fir, but of course now that has been modified to SPF. I have never seen a truss web pop like the one in that pic and can't remember ever finding trusses damaged by forces other than brain-dead humans with tools.

One thing I see in the newer homes is 2 X 3's for the webs. So the engineers have decided the older homes were over-built. ;)

D Fir, Larch, and SYP are pretty much standard for top and bottom chords. Web materials can vary from utility grade up, as long as they meet the design pressures for the length and location. Which is pretty much determined by computer engineering. Some webs have little to no stress, either in compression or tension, while others have huge loads.

A 2x4 MSR 2700 is stronger than a 2x6 Standard grade, which is only 1500. it is all in the engineering. Jerry pointed out the "double knot". Known as a combination knot in grading terms, a very weak point.

When dealing with MSR lumber is when a 2x4 is not the same as any 2x4. You cannot just go down to a lumber yard and buy MSR lumber. They do not stock it. Truss plants buy it up and it is more expensive.

MSR 2700 is machine stress rated to 2,700 lbs. MSR, 1500, 1750, 2100, and 2700 were common 20 years ago. I am sure things have changed.

[Mark Reinmiller]

I am a licensed P.E.

Usually when I see failures like that it is probably from mishandling. Trusses do like to be bent, but contractors do it often. When I see cracked members I look close at the plates too, because they can pop loose from bending.

[JeffGHooper]

I am a licensed P.E.

Usually when I see failures like that it is probably from mishandling. Trusses do like to be bent, but contractors do it often. When I see cracked members I look close at the plates too, because they can pop loose from bending.

TPI handling must be followed!

[Jerry Peck]

The broken trusses I find are also usually from mis-handling.

Other than mis-handling, the typical location of breaks is at those all-to-common double knots (combination knots).

I find more trusses with loose truss plates than with broken webs or cords.

I probably find as many broken vertical members and top/bottom chords as I do diagonal webs.


TPI handling must be followed!

You are kidding us ... right? :thumb:

I doubt anyone I've seen installing trusses has ever looked at, much less actually read and understood the requirements for handling metal plate connected wood trusses:
- http://support.sbcindustry.com/docs/06_BCSI_booklet_FINAL.pdf%20?PHPSESSID=8mgnumrsb78 hnfio8j0p9515d2

(Otherwise we would not find very many damaged (broken) trusses and/or loose truss plates. Then take the Sawzalls TM away from the trades and most of the rest of the damage (cuts) would go away.)

[Mark Reinmiller]

The broken trusses I find are also usually from mis-handling.

Other than mis-handling, the typical location of breaks is at those all-to-common double knots (combination knots).

I find more trusses with loose truss plates than with broken webs or cords.

I probably find as many broken vertical members and top/bottom chords as I do diagonal webs.



You are kidding us ... right? :thumb:

I doubt anyone I've seen installing trusses has ever looked at, much less actually read and understood the requirements for handling metal plate connected wood trusses:
- http://support.sbcindustry.com/docs/06_BCSI_booklet_FINAL.pdf%20?PHPSESSID=8mgnumrsb78 hnfio8j0p9515d2

(Otherwise we would not find very many damaged (broken) trusses and/or loose truss plates. Then take the Sawzalls TM away from the trades and most of the rest of the damage (cuts) would go away.)

Jerry, If men read instructions you and I may not have any work.

[Jerry Peck]

Jerry, If men read instructions you and I may not have any work.

Mark,

How true, how true. :biggrin:

What I thought you were going to say was 'If men read instructions ... what would women be needed for?' :) (Okay, okay, to all the women, that's a joke ... okay?)

[Randy Mayo]

Because of the location of the break it is a pretty easy fix. Around here the engineering would be more like $500. The work could be done for $250 if the contractor does not charge much for their labor. I would think about $1000 total, and that could be low, depending upon your location.

Regarding how serious it is, any damaged truss should be repaired. If they don't fix it, you may have to fix it for the next buyer. It could also cause local sagging in the roof, which could make the repair more expensive later.


I agree with Mark, my engineering fee for a standard Fink, Queen type truss would be in the $400 to $500 range. That attic appears to have sufficient room to work, so any good contractor could do the repair in short order.

[Mark Reinmiller]

I have repaired a few trusses myself when I thought I could do the work in one trip. To to the engineering I have to perform calculations and for plate connections make a drawing so the contractor can do the work correctly (they often don't, even with drawings). Then I am often asked to inspect the work. If I know what needs to be done ahead of time I have done the engineering onsite, performed the work, and inspected my own work in one visit. I save on travel time and drawing time, so the repair is more cost effective for the owner.

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I have repaired a few trusses myself when I thought I could do the work in one trip. To to the engineering I have to perform calculations and for plate connections make a drawing so the contractor can do the work correctly (they often don't, even with drawings). Then I am often asked to inspect the work. If I know what needs to be done ahead of time I have done the engineering onsite, performed the work, and inspected my own work in one visit. I save on travel time and drawing time, so the repair is more cost effective for the owner.

[JeffGHooper]

I have repaired a few trusses myself when I thought I could do the work in one trip. To to the engineering I have to perform calculations and for plate connections make a drawing so the contractor can do the work correctly (they often don't, even with drawings). Then I am often asked to inspect the work. If I know what needs to be done ahead of time I have done the engineering onsite, performed the work, and inspected my own work in one visit. I save on travel time and drawing time, so the repair is more cost effective for the owner.

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I have repaired a few trusses myself when I thought I could do the work in one trip. To to the engineering I have to perform calculations and for plate connections make a drawing so the contractor can do the work correctly (they often don't, even with drawings). Then I am often asked to inspect the work. If I know what needs to be done ahead of time I have done the engineering onsite, performed the work, and inspected my own work in one visit. I save on travel time and drawing time, so the repair is more cost effective for the owner.

In Florida our Licensing Laws prohibits the Fox from watching the Hen House. A PE cannot sign off his own work, only the work of others. :p

[Trent Tarter]

That's a simple repair and would require no more than an hour to repair and about $20 or less in materials. If nothing has dropped or settled, I would bypass an engineer and just have a qualified contractor repair it.

[JeffGHooper]

That's a simple repair and would require no more than an hour to repair and about $20 or less in materials. If nothing has dropped or settled, I would bypass an engineer and just have a qualified contractor repair it.

Are you generally in the habit of violating building codes and breaking laws Trent? Or is it just for this one thing?

[Mark Reinmiller]

That's a simple repair and would require no more than an hour to repair and about $20 or less in materials. If nothing has dropped or settled, I would bypass an engineer and just have a qualified contractor repair it.

According to most builder codes trusses cannot be altered or repaired without a design from a licensed design professional or truss manufacturer. It is a simple repair that almost no contractor does correctly because they have no idea what the force is in the member or what is required to reinforce the member.

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In Florida our Licensing Laws prohibits the Fox from watching the Hen House. A PE cannot sign off his own work, only the work of others. :p

P.E.s sign off on their own work for a living. Any engineer that designs something and seals his design signs off on his own work.

[JeffGHooper]

According to most builder codes trusses cannot be altered or repaired without a design from a licensed design professional or truss manufacturer. It is a simple repair that almost no contractor does correctly because they have no idea what the force is in the member or what is required to reinforce the member.

Mark, ALL, Building Codes REQUIRE Engineering for trusses.

His comment IS exactly why we see the $hit we do out there.

Trent, I decided to start a new business. Brain Surgery by Jeff. Bring your family over and I will get started tomorrow. After all it is not that hard to cut a hole in someone's head and fish around in there. Probably only take a few minutes and about $10.00 worth of sutures. :o

[JeffGHooper]

P.E.s sign off on their own work for a living. Any engineer that designs something and seals his design signs off on his own work.

I am not talking about the design and seal or when you come back later when the work is done and sign off after the work is done by others.

FL Statute 471 is a little different when it comes to building inspections and plan review.
In part, 471.045 Professional engineers performing building code inspector duties. A professional engineer may not perform review upon any job that the professional engineer or the professional engineer’s company designed.

[Mark Reinmiller]

Here are a couple web member from trusses I looked at today. No damage, but not good quality wood (No. 3 SP).

315723157331574

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Here are a couple web member from trusses I looked at today. No damage, but not good quality wood (No. 3 SP).

315723157331574

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Here are a couple web member from trusses I looked at today. No damage, but not good quality wood (No. 3 SP).

315723157331574

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Here are a couple web member from trusses I looked at today. No damage, but not good quality wood (No. 3 SP).

315723157331574

[JeffGHooper]

Mark, are you getting an error message after posting?

That is why it is posting multiple times. When I get it I close the window and open it again. My post only appears once then. Brian has been trying to fix this.

As you know, #3 is allowed for webs, just not top and bottom chords. Even utility grade can be used for some webs. All depends as you know on the Engineering.

[Vern Heiler]

As you know, #3 is allowed for webs, just not top and bottom chords. Even utility grade can be used for some webs. All depends as you know on the Engineering.
Jeff, this does beg the question: Why is an engineered repair so difficult or expensive for such a low grade web requirement?

[Trent Tarter]

Are you generally in the habit of violating building codes and breaking laws Trent? Or is it just for this one thing?

Sure it's a good idea to hire and engineer to tell you how to replace the 2"x4" and install gusset plates. But the reality is that it's a simple and minor repair that any component contractor could easily repair with confidence.

[JeffGHooper]

Jeff, this does beg the question: Why is an engineered repair so difficult or expensive for such a low grade web requirement?

Short dumbed down version.

Every truss relies on every component to transfer the loads to the outside or a bearing point. Every truss in the home relies on the other trusses as it is a system. The webs are in tension, or compression, depending on where they are located, or how a load is applied. They have dead loads, live loads, moment loads and a few others mark can fill you in on. This can cause webs to bow, buckle, or break when under compression which is why some require lateral braces at specific locations. If you do not have the truss engineering for the project you may not even know if a required brace is missing.

One web might have a huge load on it, which will dictate type of material, machine stress rating, and size of the truss plate. Sometimes even 12" x 12" truss plates at a 2x4 connection. All depends on the load. While others may have very little, like a valley or hip jack and they may have webs made of very poor material due to little to no load.

A field repair can be very difficult in that the truss plates are put in with pressure, (they cannot and are not approved to be beaten in as it damages the teeth). So you have to get a mobile press up in the attic to compress the plate in. Beating them in with a hammer or using nails is NOT a good idea because they will not hold and beating on a truss is always a BAD idea. See TPI.

Mark as a PE can add the longer version. Nothing is as simple as it looks when it comes to trusses.

Anyone see the video of the garage roof collapsing on that campus last week with all the students standing on the garage? Good for a laugh.

[Vern Heiler]

Short dumbed down version.

Every truss relies on every component to transfer the loads to the outside or a bearing point. Every truss in the home relies on the other trusses as it is a system. The webs are in tension, or compression, depending on where they are located, or how a load is applied. They have dead loads, live loads, moment loads and a few others mark can fill you in on. This can cause webs to bow, buckle, or break when under compression which is why some require lateral braces at specific locations. If you do not have the truss engineering for the project you may not even know if a required brace is missing.

One web might have a huge load on it, which will dictate type of material, machine stress rating, and size of the truss plate. Sometimes even 12" x 12" truss plates at a 2x4 connection. All depends on the load. While others may have very little, like a valley or hip jack and they may have webs made of very poor material due to little to no load.

A field repair can be very difficult in that the truss plates are put in with pressure, (they cannot and are not approved to be beaten in as it damages the teeth). So you have to get a mobile press up in the attic to compress the plate in. Beating them in with a hammer or using nails is NOT a good idea because they will not hold and beating on a truss is always a BAD idea. See TPI.

Mark as a PE can add the longer version. Nothing is as simple as it looks when it comes to trusses.

Anyone see the video of the garage roof collapsing on that campus last week with all the students standing on the garage? Good for a laugh.
I thought hammers were obsolete:D. (Good answer though)

[Jerry Peck]

Jeff, this does beg the question: Why is an engineered repair so difficult or expensive for such a low grade web requirement?


Because the same contractor who sets their gun pressure up and drives roof sheathing nails over halfway through the roof sheathing is the same "skilled" and knowledgeable contractor who is going to slap a 2 foot long piece of SPF ("white wood") over the break in the truss and shoot those same nails that they used for the roof sheathing.

[JeffGHooper]

Sure it's a good idea to hire and engineer to tell you how to replace the 2"x4" and install gusset plates. But the reality is that it's a simple and minor repair that any component contract could easily repair with confidence.

You are rendering an opinion on the repair of a structural component that is required to be engineered per the Building Codes. Just out of curiosity, what credentials do you possess to render such a determination?

Can you tell me if that lumber in the photo is a 2x4 that is MSR 2200?
Can you tell me if that lumber in the photo is a 2x4 that is MSR 2700?
Can you tell me if that lumber in the photo is a 2x4 that is MSR 1750?
Can you tell me if that lumber in the photo is a 2x4 that is MSR 1500?
Can you even tell me the difference between the ratings and what load each will assume?
Can you tell me if that is a 45,10,10,0?
Can you tell me anything about the loading of the truss or the web?

Nothing is simple, and to even assume anything about a truss without knowing these facts is irresponsible and reckless, or could put someone's life in danger. A Contractor who would perform a repair on that without Engineering is not competent, but rather, incompetent, or should I say a "Fool".

If you perform Engineering and the building collapses you had better be prepared to stand behind the repair for, get this, "A Lifetime." Ask any Engineer.

[Mark Reinmiller]

Sure it's a good idea to hire and engineer to tell you how to replace the 2"x4" and install gusset plates. But the reality is that it's a simple and minor repair that any component contractor could easily repair with confidence.

If that is true, then why do I almost never see proper repairs to trusses. Do you want to suggest what you think is an acceptable repair?

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Sure it's a good idea to hire and engineer to tell you how to replace the 2"x4" and install gusset plates. But the reality is that it's a simple and minor repair that any component contractor could easily repair with confidence.

If that is true, then why do I almost never see proper repairs to trusses. Do you want to suggest what you think is an acceptable repair?

[John Kogel]

If that is true, then why do I almost never see proper repairs to trusses. Do you want to suggest what you think is an acceptable repair?

He did in another post, replace the 2 x 4 web and bang on new truss plates. But Jeff has already poo-pooed doing that with a hammer. Use your head, man. :D

If I may suggest something, a repair I sometimes see, just asking, is large pieces of plywood both sides of the broken area, with lots of galvanized nails about 2" apart. What say thee about that?

BTW, I never see defects like those pics in trusses here.

[JeffGHooper]

He did in another post, replace the 2 x 4 web and bang on new truss plates. But Jeff has already poo-pooed doing that with a hammer. Use your head, man. :D

If I may suggest something, a repair I sometimes see, just asking, is large pieces of plywood both sides of the broken area, with lots of galvanized nails about 2" apart. What say thee about that?

BTW, I never see defects like those pics in trusses here.

John, I have actually seen field repairs like the one you mentioned using plywood, glue and nails that was specified by an Engineer.

I am sure that Mark would agree that if you have that letter, and the Engineer specified that correction, after performing a Rational Analysis, and it was performed to that letter, you are good to go. Oh, in my neck of the woods I have to add the caveat, and a permit was obtained, and signed off. :)

[Mark Reinmiller]

He did in another post, replace the 2 x 4 web and bang on new truss plates. But Jeff has already poo-pooed doing that with a hammer. Use your head, man. :D

If I may suggest something, a repair I sometimes see, just asking, is large pieces of plywood both sides of the broken area, with lots of galvanized nails about 2" apart. What say thee about that?

BTW, I never see defects like those pics in trusses here.

Gusset plates are a common and accepted repair for damaged joints. OSB is actually better than plywood for that, but either work fine. When this repair is not engineered I often see too few nails; improperly placed nails; gaps between the gusset plates and trusses; drywall or deck screws instead of nails; too few nails; did I mention too few nails?

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He did in another post, replace the 2 x 4 web and bang on new truss plates. But Jeff has already poo-pooed doing that with a hammer. Use your head, man. :D

If I may suggest something, a repair I sometimes see, just asking, is large pieces of plywood both sides of the broken area, with lots of galvanized nails about 2" apart. What say thee about that?

BTW, I never see defects like those pics in trusses here.

Gusset plates are a common and accepted repair for damaged joints. OSB is actually better than plywood for that, but either work fine. When this repair is not engineered I often see too few nails; improperly placed nails; gaps between the gusset plates and trusses; drywall or deck screws instead of nails; too few nails; did I mention too few nails?

[John Kogel]

Gusset plates are a common and accepted repair for damaged joints. OSB is actually better than plywood for that, but either work fine. When this repair is not engineered I often see too few nails; improperly placed nails; gaps between the gusset plates and trusses; drywall or deck screws instead of nails; too few nails; did I mention too few nails?

[Thanks Mark. Why is OSB better than plywood? Nail heads will pull thru OSB if you pry on it. Worse if it is water-soaked.

[JeffGHooper]

Thanks Mark. Why is OSB better than plywood? Nail heads will pull thru OSB if you pry on it. Worse if it is water-soaked.

Because you are worrying about shear, not pull out. There should not be any water soaked OSB in an attic! ;)

[John Kogel]

Because you are worrying about shear, not pull out. There should not be any water soaked OSB in an attic! Should not be any busted trusses either. ;)

[Mark Reinmiller]

Thanks Mark. Why is OSB better than plywood? Nail heads will pull thru OSB if you pry on it. Worse if it is water-soaked.

Mainly because the specific gravity of OSB is higher (unless you are using SP plywood). Nail strengths in shear are based on S.G., so less nails are needed. OSB has better shear strength than PW. 3/4" OSB is used for gusset plates. Heads pulling through the OSB is not an issue.

[John Kogel]

Mainly because the specific gravity of OSB is higher (unless you are using SP plywood). Nail strengths in shear are based on S.G., so less nails are needed. OSB has better shear strength than PW. 3/4" OSB is used for gusset plates. Heads pulling through the OSB is not an issue.Ok I can accept that from a techy point of view. Too bad that stinking OSB gets moldy and rotten, because it would be a good building material otherwise. :D

Maybe not on the East coast so much.