Nestor_Kelebay

I think the proof lies in the pudding.

By his own account, ChrisM says that his floor is much more rigid now than before. That means there's less deflection of the trusses now than before, and that HAS TO MEAN that the new assembly is stronger than what he had before.

I don't accept that stresses due to swelling and shrinking in a relatively soft material like plywood is going to cause problems down the road.

Wuzzat?

at the cost of becoming indeterminate. Methinks it may carry the seeds of its own destruction.

frozenstar

Wow. Those are some really nice reply. I had a good read guys!

ChrisM

First let me thank everyone for their very knowledgeable replies and for taking the time to post them!

My initial plan was to plywood just one side of each truss with 5/8 ply. The engineer however was the one who said to do both. I suppose at that point I should have used 3/8 ply but I thought the engineer knew his business. The structure is truly stronger but how it will handle additional weight and perform in the future is my real concern. I have a home inspector who is a neighboring town's building inspector coming next week to look at the project. I'm going to show him all these replies and work from there. I am inclined to listen to Nestor_Kelebay but can't ignore the assestments of Wuzzat and CraigFl. The primary goal is a safe code compliant structure not only for my family but for anyone who may buy this home in the future.

Any additional sugestions would certainly be appreciated and I'm sure will be a real reference for anyone doing a similiar project in the future.

travelover

I admit it has been about 30 years since engineering school. Can you please explain why this is an issue for this homeowner?

oldognewtrick

Travelover, I wanted to ask this my self, but after looking at the pics I would think that the weakest part of the boxed area is that all load or flex would be at the joints of the ply. If the joints would of been staggered, like we do when installing plywood decking, the load point would be changed to two locations instead of one, or spread out over the joist.

But then I'm just a roofer...

DaveSTNJ

I had the same problem in my home with floor trusses. A structural engineering firm designed a very similar fix with plywood gussets on each side of the trusses. I can send photos and the drawing if that would help.

DaveSTNJ

I should also add that the engineer seemed like he had not encountered this problem in the past and seemed less than totally certain about the fix.

ChrisM

Well it's been over two years and the floor is still stiff and strong! Post the pics I'd like to see them.

nealtw

On two occations we have had roof trusses deamed under engineered and this is the fix they came up with. If the city were to fail it, you just shop for an engineer who will write the report that the city will accept An engineer would have a lot more nails in it.