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Floor Truss Repair

claygear's picture

I have a customer who's selling his townhouse.  The buyer's home inspector discovered a bow in the living room ceiling +/- 3' from the bearing wall.  I opened up the ceiling for him and discoverd that the top chord of a 14" open web truss is cut and the truss has sagged.

Here's the real problem:  The buyer has asked a friend / architect to recommend a solution.  He has recommended that the truss be jacked back into position, and two 12" TJ's be scabbed the full length (+/- 18') of the truss.  Obviously, this involves tearing out a major piece of ceiling, and I'm not even sure that this solution is constructable with the space limitations present.

There must be a better way?  Any recommendations for a repair?  I have some thoughts, but would like some more experienced opinions.

(post #96758, reply #1 of 10)

The top chord just needs to hold up under compression. In theory, jacking it up and inserting (wedging, actually) a piece of the appropriate length into the gap should suffice. If there is an obstruction that prevents this, I would think some sort of steel frame could be built around the obstruction to take the compressive force. (Would take a dash of engineering to calculate the force the frame must stand.)

Another possible option is to jack up the truss and sandwich the bad spot with 3/4 plywood (glued and nailed) or some such.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #96758, reply #2 of 10)

You cant alter trusses on this site . No way in hell you can get by with it here .

Sue the truss company , they never make a mistake . They are always right .

Am I venting ? Yes and just kidding too.

Serious ;

The truss comapny should be contacted on faulty workmanship, if you tear the rock out and decide the truss it self crumpled. Most likely , its a plumber with a sawsall. ..... I guess Im too biased to answer this post . Ive seen more BS on trusses in the last month than I care to see the rest of my time working. A plumber should be licensed to operate a sawsall. Ive seen too much of that too. Sorry . Im sure Ill feel better tomorrow.

Tim Mooney


(post #96758, reply #4 of 10)

Only one problem with this.... The house was built 18 years ago.  It took 18 years, the weight of a 50 gallon water heater and a clothes washer above to cause the truss to begin to fail. 

(post #96758, reply #5 of 10)

Now the plot thickens .

" The house was built 18 years ago.  It took 18 years, the weight of a 50 gallon water heater and a clothes washer above to cause the truss to begin to fail."

The load of the washer and the hot water heater , hence a utility room should have been engineered by plans stamped by an engineer on load.

Of course after 18 years , all this is moot.  Youve still got a problem you are going to fix. You cant put another truss in its place after the house is built normally. Looks like you are going to have to tamper with this truss. A truss engineer would be the best thought of solution , or you could beef it up your self after you jacked it back in place. You could make your own glulam on both sides of the present truss by staggering plywood , gluing and screwing. You could do four layers on both sides with each layer including both sides cut at staggering lenghts just like a glulam. Of course there is the present truss that was supposed to hold it and did for a number of years. It should be worth the same put back right.  But again it would be truss tampering .

Tim Mooney


(post #96758, reply #8 of 10)

Tim, did you have a bad day?  You sound just a little frustrated.  I knew a plumber once and his nickname was "Hack".  When I knew he was coming behind us I would tell the builder not to call me when Hack cut out a support beam.

I guess we will never get away from guys who destroy other's work.  If builders would quit hiring them then I guess that would work.  But for some strange reason the builders keep on hiring the subs who destroy the framing or something else.

I know it has to be bad on your end of things.

WEll, cheer up.  Today you get to go back into the field and  interact with guys who may or may not care what they do.  Maybe you will only meet the caring ones today.

We care,

James Hart

(post #96758, reply #3 of 10)

We've had to repair damaged floor trusses before. It usually involves a substantial plywood gusset.

The last floor truss we were told to repair (to pass rough inspection) was where a plumber drilled a 3.5" hole through the center of the 3.5" top chord leaving NOTHING. The engineer repair required an 8' plywood gusset glued and nailed on both sides of the truss. I gathered my plywood and glue and went over to do the repair. The builder didn't mention that there were two heat ducts running through the truss adjacent to the damaged area. In addition, there were several pipes and wires. All totaled, I figure I could put about a 6" plywood scab over the damaged area...which we all know is useless.

I simply turned around, walked out and waited for the builder's return call. I'm still waiting 6 years later.

Any plumber who cuts a floor truss should have every one of his pipes and drains hacked in half.



Warning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!


keep looking for customers who want to hire  YOU.. all the rest are looking for commodities.. are you  a commodity ?... if you get sucked into "free estimates" and  "soliciting bids"... then you are a commodity... if your operation is set up to compete as a commodity, then have at it..... but be prepared to keep your margins low and your overhead  high...."

From the best of TauntonU.

(post #96758, reply #6 of 10)

Like Blue said, most truss repairs involve plywood.

If you want/need an engineer's seal on a repair, any truss company should be able to steer you to someone who has the capabilities to do it.

How much plywood is needed and how many nails are needed depends on a lot of things. Like where it's cut, the web pattern, lumber species and grade, span, etc. It's not something anyone here can come up with.

Learn from the mistakes of others. You can't live long enough to make them all yourself.

(post #96758, reply #7 of 10)

I have done a lot of roof truss repairs (fire repairs) and the engineer usually has us sister on 2x4s on both sides then 1/2 plywood with 3 inch sds screws. Should be roughly the same princible but an engineer should have no problem giving you a set of plans for it.

(post #96758, reply #9 of 10)

Clay, repairing the truss does not seem to be the problem, a few suggestions have already been made that would solve the sagging ceiling. As I see it the problem is the expense of removing the ceiling to get access, once you have access it should not be that costly. What always bothers me, in these situations, is replacing and matching the stippel. If the living roon is conected to the dining room to the kitchen to the hall to the foyer and so on it usually all has to come off and be retextured.If you are lucky the stippel is isolated to the one room you are working in.

I think I will post this question about removing stippel.

(post #96758, reply #10 of 10)

Thanks for the comments, but all has been resolved,

BTW: We don't stippel in these parts.