Roof Truss Repair - Did I make my plywood too short?

[SteveSch]

Hello all,

I am working on a 1971 mobile home. The roof trusses are 1x2 and 2x2 material. Over the years the roof has sunk in, and many of the trusses have broken. Mainly the top boards.

I read right here on this great forum about scabbing plywood to the sides of the trusses to repair the roof, and make it livable again. Thanks guys. Using the great instructions in the post, I measured every 6 inches and made a plywood truss. I then used Liquid Nails and screws to attach the plywood to the side of the truss.

Well it worked great and the roof is starting to look normal again.

I made 2 plywood pieces for every truss. One for each end of the truss. I cut the plywood short, so there is a gap in the center for ventilation.

In total, I left a 2 foot space in the center with no plywood. It has been standing up to the weather for just over a year, Colorado snow. It was recommended to me that I do something to brace the center, where there is no plywood to strengthen it.

So, should I have made my plywood supports longer, or should they be fine?

I was thinking of using 3/8 plywood for the actual ceiling.

Thanks in advance,
Steve

[Greg]

My initial thought is ANY additional support is a good thing. The home held up 40 years the way it was, with your additional support it should be fine another 40.

Perhaps JD will add to this.

Greg

[HouseMedic]

If you are worried about the air circulating past the plywood gusset supports you could always drill 2-1/2" holes in the plywood every so often to let air get through. Just keep the holes far enough apart to keep the strength of the plywood intact.

Ron

[SteveSch]

Thanks for the opinions. I will start putting a ceiling up.

Steve

[JD]

To add support to the middle of the truss, you could add a diagonal brace which could tie the two sides of bracing together or use a heavy gauge Simpson nail plate to the bottom/middle oh the truss. The 2 1/2" holes idea is a good one also.