out of square

[cj]

i have a lean to (sp?) sort of roof attached to a neighbors house that is out of square by quite a bit. the lean to is constructed of 2x8 joyces on top of that 1x4 slats and then 1/2 inch osb board. the slats and osb board extended past the joyces on 2 sides which means they can be trimmed. i guess it's not that big of a deal that the roof is out of square except that we will be covering the roof with 3 tab shingles and we don't want the shingles to look out of square(the seams) where would be a good place to start to ensure the shingles look square on an out of square roof? thanks, cj

[RicodJour]

If you use dimensional shingles (aka architectural) the out of square condition will be less noticeable.

How much is it out of square? With three tab shingles you will really only notice the lines running up the roof near the left and right edges. Generally I'd tell you to layout the shingles from the center and start in the bottom left corner (if you're right handed), but if the discrepancy is too great you might have to tweak that a bit to maximize the space between the most out of square edge and the first "seam" of shingles.

R

[harry k]

If you use the 'professional' offset on 3-tab the out of square will hardly be noticeable. The bundles give the amount to offset each row and you wind up with the 'lines' running up at a diagonal.

In general, always avoid the layout that resules in straitht lines running up the roof - looks poor and is a sign of amateur work.

Harry K