I was up in the attic today, and noticed that I had a broken roof truss. Not sure how long it's been that way. It didn't look too new.
Anyone ever dealt with this?
Rather then replacing it, I was just thinking about sistering in (or sandwiching it ) another 2x4 with some screws and maybe some construction adhesive.
This pic I found is a pretty good likeness of it.
If it were mine, I would sister on both sides the full length of the run and call it done. I would use a lot of nails or screws and stagger them.
Colbyt
I agree with Colby, wouldn't hurt to add construction adhesive as you proposed.
I am still looking for the truss plan I got for my addition but as I recall the engineered truss repair instructions for damaged trusses said you sister the whole length of the member or a max of 8 feet and use a shit load of nails/screws. The nailing schedule was on the plan. Nail guns are the preferred method to avoid further damage. To that end, big screws are better. Predrill the first few holes in one member a bit bigger than the screw to get a tight fit before you run in the rest of the screws.
The problem with adhesives is getting the engineer who stamps the repair plan to sign off on the longevity of the adhesive. Make no mistake, a code compliant repair is an engineered solution. Usually a good truss plan will have repair instructions included for the various members so if it is damaged in transit, you are not holding up the job waiting for engineering or a new truss.
Agree: For self home repair: To fix; if it is similar, say, to that shown in picture I would sister both sides with longest length 2x4s that will fit. Glue both side to the broken one using screws to pull the whole thing together. Don'think bolting through would be necessary! Maybe even a temporary clamp or two for few days! Be the strongest truss up there! Doesn't need to be thing of beauty, although ponder on why it broke!. We used lumber glue and then had to change something again; and getting the new wood out tore the surface off the wood after a only a couple of weeks setting up! No wonder some of it is called Gorilla or Bulldog, or something glue! Great stuff.
If there is no knot right there you have a valid question. If there is a knot there the truss manufacturer has a serious quality control issue. Was there any evidence of a roof impact? Did something happen in the attic? What do the connecting plates look like? Any signs of a lateral impact?
...and lag bolts instead of screws.
I saw a house some years ago. The header beam across the garage double door was poured concrete and after years it failed. About the center it collapsed. You could see a "cup" in the roof. Didn't get to see the attic, but the contractor was "thinking" there would be rafter damage. Nothing hit the house, the beam just failed one day.
Replace the whole 2X4. Easily done and the best way. I've sandwiched some 2X10 floor joists and could never get them to last long. Ended up knocking them out from center beam to sill and replaced them.
No - do NOT use lag bolts. Many screws in a roughly 2 or 3 inch grid will hold more and weaken the structure less than larger lag screws. I would definitely also glue the joint - good carpenter's glue would be adequate, and urethane glue like Gorilla Glue Or Leapages PL Premium would be excellent. drill the sister plates ovesize for one screw every 2 feet or so to pull the repair together firmly then drive the remaining screws. Properly screwsd together clamping would be totally redundant.
obvously not a properly re-enforced concrete.
A few years ago I did a repair like this and contacted an engineer buddy for advice. I placed strips of 1/2 plywood 8 ft long on either side of the truss Plywood ran the length of the brace overlapping the gussets.
Jimmie
I like words like obvious, ordinarily and consequentially ..
Helps me describe it.
I'd use some method of pulling it together before sistering anything to it. I'd probably get creative with some cable, eye hooks and a turnbuckle to bring it together, then sister one side, screws and glue! After a few days I'd remove the cable if in the way then sister the other side. Yes more small screws instead of less large ones.
Lordy. It is a residential roof truss, not a damn bridge. Some 2x4s across adjacent trusses, top and bottom, and some hammered-in stiff legs between the 2x4s, and you can take all the load off the broken piece. Same concept as making a temporary wall when you have to work on a load-bearing partition. Either switch the broken board out and use new nailers or gussets to tie it back in, or sister both sides.
I probably wouldn't even make it that complicated. Measure the same piece on next truss over to get the length, cut the replacement, remove broken piece, reinstall using some sort of lever or jack if needed to get it back on the original mount points. I'd probably use a saber saw and metal blade to cut away that part of nailer plates, and put it back with oversize plywood gussets. A few dabs of construction adhesive to position them, and then screw the hell out of them. I used to see similar work done all the time down south, to repair where an HVAC guy butchered trusses to install something.
The easiest thing to do if its broken like the OP showed in the picture is to just take that part out an replace it. There is no load on the thing.
Jimmie
Well you mention some type of lever or jack, that sounds fine but until now no one mentioned pulling the broken joist together before sistering it. Maybe just a strong ratchet strap would pull it together? Whatever works. Just do it BEFORE sistering it!
Before I did that I would make 2 cuts through the break about 1" apart so the two pieces do not touch when pulled back into place. When you get the correct length temporarily screw a 2x2 on the top side of both halves to keep the truss true (keeping the ratchet strap in place).
Once you sister the truss on both sides (glue it and screw it) you can remove the 2x2 and strap... and Bob's your uncle!
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.