I am trying in vane to figure out how to layout the shingle pattern for my garage roof that I am about to install. I will be using 36", 3 tab fiberglass shingles. My problem is that no matter how I try to layout the shingles(of graph paper) I always seem to end up with some courses that the last shingle is only 2" or 4". Not nearly enough space to nail, especially if you consider 1" of drip edge(rake and eave), 1/4" overhang, and 3/4" trim board. I have tried many layout patterns and cannot to seem to overcome this problem. For instance here are some layouts I have tried:(Each side of garage gable roof is 248" wide including drip edge and 1/4" overhand) 1) Start 1st course with full shingle; Start 2nd course with 30" shingle(6" removed) Start 3rd course with 24" shingle Start 4th course with 18" shingle Start 5th course with 12" shingle Start 6th course with 6" shingle Start 7th with full shingle and continue pattern. Using 248" the last shingle of the 2nd course will only be 2" wide. The rest of the courses should be acceptable since 6" is the next smallest.
2) Starting from the center(124") strike vertical line. Strike 5 more vertical lines, each 6" apart. Start 1st course with full shingle at line. Start 2nd course with full shingle at second 6" vertical line(130") Start 3rd course with full shingle, again indented 6" Continue pattern on full shingle, indented 6" until and including course 6. Course 7 starts at the 124" center line and pattern repeats. Using this layout course 3 will end with only a 4" shingle and course 5 will have a 4" shingle at the beginning of the course.
3) I've also tried with 6" off the first course, 18" off the first course and several other layouts to no avail.
The only thing I've been able to come up with, is NOT having a pattern using 6 courses. Everything I read thoug says 6 course patterns. The only thing I tried that comes close is a 4 course pattern: Start course 1 with 24" shingle Start course 2 with 18" shingle Course 3 with 12" shingle Course 4 with 6" shingle The smallest piece this produces is 6". It would work using a 3 course pattern too with smallest being 8". The only problem with this is that the where the shingles butt end to end, there will only be 3 courses between the ones that align.
So I'm stumped as to how to layout this roof. It seems that it would be simple but for me that hasn't been the case. Any advise or help is appreciated. I've been to all the roofing websites..thats where I got the layout patterns etc but they don't work for me. I also tried different offsets of 4 and 5".
Thank you for your time and help...also to those who replied to my roofing felt question..thank you much!
PS: Sorry this message is so long but I want to be certain to give accurate information.