Keeping roof sheathing straight

[ScottA]

Well I didn't get any sheathing done today but I did manage to pick up the rest of material I needed and some scafolding. I'm going to start in the morning and was wondering if anyone knows a good trick to keep the sheathing lined up straight on the roof. I was thinking of running a string line along the front edge. Any advice or tricks anyone has?

[rwanders]

I've found that tacking a piece of 1x4 or similar piece along the rafter tails at the eaves really helps keep you straight and also keeps the sheet of plywood or OSB from slipping off the roof.

[Redoverfarm]

Don't forget to allow for a overhang of the sheeting.  Do not hold it flush to the rafters.  Then your drip edge and allow shinglkes to overhang about as much at the sheeting.  A couple of blocks on the gable end as well at the intersection of sheets to keep it constant.  If you hold the ends true and the bottom true it should work out. If not don't blame the sheeting.

[Willy]

Well I didn't get any sheathing done today but I did manage to pick up the rest of material I needed and some scafolding. I'm going to start in the morning and was wondering if anyone knows a good trick to keep the sheathing lined up straight on the roof. I was thinking of running a string line along the front edge. Any advice or tricks anyone has?

I allways measured to make sure the sections were square/even first I was going to sheet. Snaping a chalk line for the first row can help since lining up the eve side is hard by yourself. Then I lay the eve course first and any corrections are done at the ridge. The first course is the important one, the rest fall in place. If it is square it should be no problem if you keep the plywood square/flush as it goes on. Make sure your first sheet is "right on" and flush the rest from there checking as you go along. After I get that sheet up I use it as a platform to slide sheets up onto. I put a couple of blocks down to keep the sheets from sliding off the roof. I just slide the plywood up a ladder onto the roof till I have a bunch and put them up repeating this till I am done. It is nice to have help but sometimes that don't happen! A point to watch for is to make sure your centers at all seams are right. Don't just nail it off and find out your creeping. Joists, rafters ect can move some or warp. Once nailed real hard to correct. Myself I tack sheets at each corner first then nail one long edge(where rafters show) for my layout nailing off the rest later. When all the sheets are up I nail the works off. This way you can get lots of sheets up while your arms are still good. You can allways nail off later. Mark

[ScottA]

Thanks for the tips. I don't how but every time I lay plywood I some how get it crooked.  I'll try harder this time. 

[Redoverfarm]

Scott if I remember correctly you are going with a shingle roof. It is a little more forgiving than metal.  You can make some adjustment where metal is not always possible.

[desdawg]

I use Willy's method and I do layout my rafters or trusses at the top of each sheet as I go up. Keeps them from "straying" off layout.