I read the article by John Carroll on Shingling from Top Down hoping all my questions would be answered for my application. They wasn’t. It was a good article with a lot of merit. But will it work for what I want to do. I have a 25-30 square house that I want to tear-off one layer of three tab and replace with dimensional. Since I would be doing this mostly myself and don’t care if it takes all summer I was going to tear off about 10 ft at a time(drip edge is ten ft plus three laps of felt) shingle that and then do another 10 ft. etc. with the idea of shutting down for a week etc. and then going at it again later when the weather is clear and I have rested up etc. My questions are 1) Is this doable with the stiffer maybe even the 40 year dinensional shingles where you have to raise up the bottom two layers for nailing. 2) what do you do about water proofing where you leave off to the the next weekend? You do need to leave a gap between the bottom of the new and the old that hasn’t been torn off to keep from bruising the new when you continue to tear off. 3) How do you handle the glue down that will result of the bottom two layers of the new and when you want to continue later? Does the tar strip stick to tar paper like it does shingles!! Like I said it was a good article but it didn’t address a tear off situation and using the stiffer dimensional shingles. If you have had any experience and can help on this type of situation I would appreciate a response. Thanks
Tony
Replies
Top down will work with any shingles that I know of except maybe T-locks. Stop your tear off at the same course all the way across the roof plane. Lap your felt over that course. Stop shingling slightly above the top of where you stopped tearing off. If you have bottom glued shingles and are going to stop for several days, use a roll of kitchen plastic wrap (don't laugh) under the course of shingles where you stopped. Peel the wrap off after you slide the new shingles under. You can also re-use the release paper from ice and water barrier if you are using that product on your project. It's also easier to nail the course that you have slipped under using a gun rather than hand nailing.
Good Luck
gl
My powers can only be used for good.
Tony,
It appears to me most of your concern is the fact that you`re planned on tearing off small portions at a time. Stripping one side entirely at a shot (15 squares) would make life a lot easier whether shingling top down or bottom up. Even if you can`t paper it all in ahead of time I think a tarp would be more protection against the elements than the make shift joint between old and new roofing. I did my roof the same way...over the course of a summer...and switching gears from stripping one day to roofing the next can just prolong the project. Good luck, and let us know how you make out!
Jay
J. D. Reynolds
Home Improvements
"DO IT RIGHT, DO IT ONCE"
Tony,
First of all, thanks for the positive comments about my article. As Grant said, the top down method will work with just about any asphalt shingle and it works well on tear-off roofs. The seal down strip is on the top of the shingle, so you don't have to worry about it sticking to the tar paper underneath. You do have to worry about the bottom edges of the second course in each section sticking to the sealdown strip on the first horizontal course (the one that is nailed high). As you may recall from my article, you have to lift up the bottom edge the second course, later, in order to nail off the first course just above the groove. If an extended period of time elapses before you come up with the section underneath, these can get sealed together pretty tight. Grant's suggestion to use plastic wrap to prevent the bottom edges of the second course from adhering to the first course is an excellent piece of advice. Alternatively, you can use wax paper. You can nail this "release barrier" to hold it in place but keep the nails in the top two inches of the shingle. To remove the plastic or wax paper, just rip it off the nails. You need not get every bit of it out but you need to get it off the seal down strips. You don't need to worry about the bottoms of the first course; they won't have a seal-down strip under them until the day you run up the section below.
One of the real pluses of this system for tear-off roofs is that you are tearing off shingles below the newly completed sections and, thus, you can easily avoid beating up your new roof. To Grant's suggestion to lap the bottom row of tarpaper over the existing shingles, I would add that you should use 30# felt rather than 15# felt. The 30# felt holds up better in the weather. There is a new kind of roofing felt available that is supposed to be more wind resistant but I haven't used it and I can't recall the name of it. Perhaps someone who reads these ramblings can give you the name of it. When you're done with the top section of the roof, the water should run down the new shingles, over the tarpaper, which in turn channels it to the top the old shingles.
To do this roof, I would set up or build a scaffold on the ground, then install the first row of roof scaffolding off the staging. I would nail the roof brackets directly on the existing shingles. These brackets, I've found, rarely leak. But, given the extended period of time you anticipate taking on this roof, I would suggest that you bevel the top edge of the roof bracket and caulk it where it meets the roof. You could also use scraps of tarpaper as a temporary flashing; slip the tarpaper under the shingle above and run it over the top of the bracket. Once this first set of brackets is in place, I would set scaffolding planks on them. Then I'd climb up on this first row of scaffolding and install the second row of scaffolding. I'd continue in this manner until I arrived at the top section of the roof. Then I'd begin the the tear-off process in the top section and do the roof essentially as described in my article.
I recommend that you do an entire side at once rather than cutting the horizontal length into sections. This may mean an investment in scaffolding planks but doing the roof all the way across will save time and make the job easier. You can reuse the planks when the job is done. (When I built my parent's house, I built their storage shed out of the scaffolding I had used for the masonry.)
Let me know how it turns out.
Best of luck,
John Carroll
Thanks for the response from all you guys. I think I can make it work. You just have to get going sometimes and things will work out. I talked to a experienced roofer who did my sisters house and he said the biggest thing with top down was with our hot climate and the sealing problem. But I was also concerned about the stiff dimensionals but apparently they bend enough. By the way lately 2 out of 3 reroofs are the 30 year dimensional shingles. They only sell for $37.00 a square vs. $32.00 for 25 yr three tab. But a lot of roofers are going straight up the roof (laddering) with them like three tabs and are not stepping them according to manufacturers directions. Maybe that isn't critical. Anyway I am definately requesting the algae resistant shingles because the black streaking is bad. Again thanks for the info. and I'm sure I'll have more questions later.
Tony
Tony,
As you probably noticed in my article, I ran the shingles, which were standard three-tab shingles, straight up the roof in a "laddered" pattern. Although some people object to this method of installation, it is used extensively, has no bearing on the performance of the roof, and looks fine (in my opinion). I have never had a customer complain about the appearance of a three-tab shingle roof that I'd run straight up.
When I use architectural shingles, on the other hand, I always follow the installation recommendations on the bundle wrappers because the pattern of installation can have a noticeable effect on the way the roof looks. You can use the top/down roofing method no matter which pattern you follow as you run the shingles. However, you will probably have to make some adjustments from the method described in my article when you lay out the offsets of the courses with architectural shingles. Some architecturals simply require a random pattern, which would simplify the process. I can't give you any advice about this part of the layout until I know what shingle you're going to use. Fire an e-mail off to me when you decide on a shingle and I'll be happy to give you a hand with that part of the layout.
John Carroll
A little off topic, but, I've always thought it's way easier to get a good looking 3 tab roof by cutting starters, starggered, say 5+5/8". I can't see how "laddering" as you guys call it would affect longevity, like others claim, but if all those slots aren't lined up perfectly it sure catches the eye. When you cut a set of starters, you get 5, or maybe 6, courses between where those slots should line up - much harder to notice any discrepencies.
I liked the article, though.
Jim,
I first heard of offsetting courses by 5 inches, rather than 6, from a roofer who hailed from Oklahoma and, incidently, abscounded owing me $200 (a lot of money in 1972). Anyway, when I went on a crosscountry trip a few years later, I noticed that that pattern was very common on the west side of the Mississippi. I've done it a few times, creating the 5-in. offset with my gauged roofing hammer. I think it looks pretty cool and it can go on quickly. I think it might be a little tricky to keep the pattern true on a cut-up roof, though. (The grooves don't return to their original alignment until the 12th course). Although some manufacturers state that this 'western' pattern is acceptable, many are silent concerning it. The National Roofing Contractors Association contends that three-tab shingles offset by 4, 5 or 6 inches perform the same. I agree. Like most manufacturers, the NRCA recommends that courses be installed in a diagonal pattern to optimize the blending of colors. The NRCA and most shingle manufacturers accept the laddering technique, with the caveat that it might create objectional color blends.
Neat and straight grooves are expected by general contractors and by consumers here and, on three-tab shingle roofs, crooked grooves are grounds for non-payment. Fortunately, it's not too hard to keep the grooves straight. If you begin the roof with a pair of vertical chalk lines 6 inches apart and follow them closely on the first vertical course, the grooves stay straight for the rest of the roof.