Repair Manual

[SteveSch]

Hello all,

New member here.

I ran across your site through google and I ma glad I did.

I have a roof problem. Old mh with the metal roof that is flat in several areas. The trusses are broken. I read the posts on using 3/8 plywood to fix the problem. I have about 15 trusses that I need to fix.

On a few there was a metal support holding the upper board and the lower board together. The metal bent and the top of the truss fell and let the roof drop. I replaced the stamped metal braces with some short 2X4s and it raised the roof quite a bit. Almost perfect but there is still a little dip in one area. When I push up on the metal it goes up with a pop. Only an inch or two. There is a slight dip looking at the roof from the top.

I have 2 questions. 1.) Does the repair manual cover rebuilding the roof trusses with plywood? Any photos?

2.) I got the impression from your site, I thought, that I could slide a narrow piece of 3/8 plywood about the truss to raise the roof. I was unable to locate that info again but I'm sure I saw it somewhere. LOL Can I use the 3/8 or 1/4 plywood to tighten the trusses and roof connection?

This is a great forum and I expect to learn a lot here.

Thanks in advance,
Steve

[JD]

Hi Steve snd welcome to the forum,

I don't believe that reinforcing the trusses is covered in the repair manual. I could be wrong though. I gave my copy of the manual to another forum member a couple of years ago. Maybe someone with the manual could answer that question for us.

I have used 3/8" cdx plywood to reinforce trusses many times. I have never tried 1/4" ply, but I would think the good stuff (not luan) would work. Maybe luan would work also, but the price, weight and strength difference between luan and 3/8" cdx makes the 3/8" a good choice to me. When reinforcing your trusses, you need to be sure not to block air flow. So a total skin sistered on the truss is not advised.

A slight depression, that is strong and secure, is not a real big deal unless it causes water to pond. There is an actual roofing definition for the term ponding. I think it is standing water over 1/4" deep lasting for more than 72 hours. I think there is a square inch stipulation too. This is probably not completely accurate, but you get the idea. My goal is always, no standing water.

JD

[SteveSch]

Hi JD,

Thanks for the reply.

The 3/8 or 1/4 I mentioned was to be cut in strips approx 2 inches wide and stuck between the top of the truss and the actual roof filling the gap, or raising the metal in this case. Kind of like a shim. I just thought 1/4 would be more flexible.

Thanks again for the answer.

Steve

[JD]

Shimming the metal up should work as long as the trusses are strong and do not deflect with weight on them. When I reinforce trusses for strength, I move the trusses top and bottom cord to where they should be and sister plywood to the sides of the truss to make them strong. When I am done with the trusses, I can actually do pull ups on the bottom cords. with just a slight deflection.

JD

[SteveSch]

Thanks JD. I'll give it a try.

I was planning on using 3/8 plywood instead of sheet rock for the ceiling. after the trusses are repaired.

I saw in another of your posts about weight of the panels. I was thinking 3/8 plywood in place of sheet rock would help to strengthen the entire ceiling and are most moisture resistant, just in case. Will 3/8 plywood be OK to use as ceiling panels?

Steve

<edit> I checked and the weight of 3/8 osb is 1.24 # sq ft and 3/8 sheetrock is 1.4# sq ft. 3/8 plywood should be fine.</edit>

If you can swing it, Okalux ceiling panels are available in some areas. Here is a link to the manufacturer. You can ask them if there is a supplier near you.

http://www.okaply.com/moduluxpanels.php

These panels are expensive, but they come prefinished with texture and don't require paint (except for touch-up where you oops) They are also the right weight for your mobile home.

[JD]

I would think plywood would be light enough. It is lighter than sheetrock I think. Probably less than a pound per foot. The Okaply product, now called Modulux, is a lot lighter, but it is also very expensive. When ordered with the 16o.c. splines, I think they are about $80 a panel. Okaply does make a plain ceiling panel without provisions for strips for about $50 each (12'x4'), which would be cheap considering the finish cost and labor of raw plywood or sheetrock. My supplier does not carry them, so I have only been able to use them once. This was a home that already had a factory ceiling with rosettes holding up the panels and no splines (plastic strips). This was before my local supplier carried the panels, so I was able to order the plain panels. That (not so local) supplier has quit carrying the plain panels and now only has the ones with the strips.

JD