Residential timber truss repair
Residential timber truss repair
(OP)
Hi all,
I'm having to repair a residential timber truss. All the plates at the roof peak have let go and the entire roof is currently shored up. Does anyone have insight on good repair methods? plywood plates with bolts? nails? Anyone have experience with these fixes.
I'm having to repair a residential timber truss. All the plates at the roof peak have let go and the entire roof is currently shored up. Does anyone have insight on good repair methods? plywood plates with bolts? nails? Anyone have experience with these fixes.






RE: Residential timber truss repair
Did the joint connections fail or are the beams themselves compromised, say from moisture or chrushing of wood fibers? We need to know more about how the failure is proceeding. A sketch would also help, both plan view and elevation of the truss.
Jim
RE: Residential timber truss repair
I've included a couple pics.I don't have my notebook on me but i believe it spans approx 28' and it is a howe truss.
RE: Residential timber truss repair
RE: Residential timber truss repair
RE: Residential timber truss repair
Having said all that, it is probably best that you use new plywood gusset plates with nails and LePage
PremiumPL Premium adhesive.Dik
RE: Residential timber truss repair
Dik
RE: Residential timber truss repair
RE: Residential timber truss repair
RE: Residential timber truss repair
RE: Residential timber truss repair
Same here... a lot of Hudson Bay northern stores were constructed using nailed trusses with plywood gussets. Stelco (I think) made hardened truss gusset nails back 45 or so years ago. When I first started engineering we used to draw the truss member forces right on the truss drawing; it was referred to as a Cremona diagram. It's how I started early in engineering.
CMHC used to have nailed truss plans for roof framing.
Dik
RE: Residential timber truss repair
As for repair:
Determine the loads in the web members and connect for full load to gusset.
Determine the resultant force for the web members in the direction of the chord member.
Connect the gusset to the chord member for this force.
Get yourself a beer... you worked hard for it...
Dik
RE: Residential timber truss repair
I forgot to point out that this residence is in a area with fairly high 1/50yr snowload (5.1kPa)
The plates are slightly deformed. I'm concerned that they will want to walk back out.
I'm in Canada but the TPIC here gives same guidelines.
This is exactly what I have heard and it seems like what happens with these plates that have thick teeth and shallow embedment.
I like the idea of having them use a nailgun.
Not sure who the truss supplier is (likely are not even around). The home is in a forestry driven community, it seems they slapped all these homes up very quick when the pulp and paper mills came in.
Perfect was exactly what I have done so far.
RE: Residential timber truss repair
RE: Residential timber truss repair
Dik
RE: Residential timber truss repair
What area? Mountains? I'm in Winnipeg.
Dik
RE: Residential timber truss repair
If one did use screws what Simpson fastener product (or other comparable brand) would you recommend?
A confused student is a good student.
Nathaniel P. Wilkerson, PE
www.medeek.com
RE: Residential timber truss repair
Screws... i think you are looking at single shear and you may run into issues with ductility depending on the screw type. I am sure simpson makes a small screw from plywood to 2x material
RE: Residential timber truss repair
RE: Residential timber truss repair
Mountainous interior of BC.
RE: Residential timber truss repair
RE: Residential timber truss repair
Just did a major repair design with sistering deficient trusses and used pre-punched 1/8" thick steel plates with through-bolting to essentially replace all of the TPI type plates. Original trusses "went south" because of tile roof loading and a bunch of hanging mechanical that wasn't properly considered in the original design (should have been, though!).
RE: Residential timber truss repair
I guess the problem with the TPI plates is that they are very tightly designed and have little latitude for installation or re-installation. I did a project about 25 years back where the truss plates had lifted and TPIC informed me that they should just be 'hammered' back in place... not, anymore.
My 'wood expert' is a member of TPIC and I quickly checked with him about repair of the truss plates and he pointed out the truss plate 'book'.
Dik