Should the cellophane strips be removed from architectural shingles during installation or left in place?
I had my roof redone 10 years ago and the contractor left the cellophane strips on (rather than exposing the tar underneath). Every wind storm some come shingles come off of the roof. I fix
this by using globs of asphalt calking to glue down the corners of every shingle that seems loose. Now I have no more trouble with those particular shingles, but do have lines on the roof where the tar I applied got warm and dripped.
Whenever I put on a new shingle I also take off the cellophane strip to stick down the edges (unlike what the contractor did).
No need to take the plastic strip off during installation. It's just there to keep the shingles from sticking together in the bundles. The tar dabs to "glue down" the shingles to each other will be where they are supposed to be during nail down and not covered by the plastic.
A roofing problem like yours happens every now and then for several reasons. One of the following
may apply your particular roof:
The tar dabs melt and glue down pretty well in hot weather but in cold weather they do not glue down until a warm day comes along, letting shingles fly off in a heavy wind before the warm day.
To mitigate this issue, in cold weather tar caulk can be applied just under the shingles, especially on the Northwest side of the roof.
According to the National Roofing Contracors Associacion (http://www.nrca.net/consumer/types/asphalt.aspx)
"Both 3-tab asphalt shingles and laminated asphalt shingles contain a strip of factory applied adhesive that is activated by the sun's heat after installation and seals each shingle to the next course. The seal strip also provides much of a shingle's resistance to wind uplift. Shingles with factory-applied adhesive have a strip of clear polyester film applied to each shingle to prevent the sealing strips from bonding the shingles together when packaged. When the shingles are installed, the self-sealing strips will not align with the plastic film strips and will bond to adjacent shingles. For this reason, the plastic film strips do not have to be removed."
Concerning the issue of your shingles, there may be other potential reasons this is happening:
1. Sometimes shingles are flawed when they arrive. They may old with dried out tar dabs. I had
one customer buy from one of those discount stores and this happened. I found out they were a color close out shingle...no telling how old they were.
We always buy from "active" roofing suppliers who are selling enough product that there is less chance of getting old shingles and being stuck with them. By going with "active" suppliers we get good shingles and don't get a mix match of dye lots.
On a side note, getting a mix match of dye lots happens when less active suppliers send out an order of shingles that were returned from order "over" orders. If shingles come from several dye lots, times of manufacturing, etc there may be several colors on one truck going to a customer resulting in those streaks you see on many roofs.
2. Sometimes the applicator can also push the shingles to close together and pucker them...not letting them set down flat as they should. If shingles are puckered they will be more likely to catch wind and come off.
3. Some contractors use staples to put shingles on a roof. We never use staples. It is easy for the installer to use too much air pressure on the air stapler, nearly driving the staples all the way through
the shingles. I have replaced several roofs where half the roof blew off in one piece and left every staple in the roof decking. Nails may cost twice as much a staples but an extra $75 spent on a customer's roof is well spent. We never, ever never use staples. Nails pull the shingles down
better onto the felt.
4. The next potential problem many homeowners have is the roofing felt. After felt is applied it can wrinkle if it rains, turns cold, etc before the shingles are nailed on. Shingles should not be applied on badly wrinkled felt. This doesn't let shingle lay flat... since they are nailed over the wrinkles.
5. One last potential problem could be the wrong length of nails or the lack of nails. Sometimes we have found roofs done by previous contractors have nails that are too short on 1 or 2 layers of shingles. Sometimes shingles also do not have enough nails. There should be 4 nails in every shingle applied to a roof.
6. If a roof is installed on a day that is drastically too cold for the job or the roof is installed in the rain, it is much more likely problems will occur later.
I have had a few shingles come off on a house or two in some windy storms. It is usually right in the same place on the roof. On one big house in Centerton it was always the NW side near the same valley. We calk-tared the replaced shingles down every time and this finally quit. I decided there must have been a wind increase in that area of the roof when the wind came in just right.
Most of the time, just a few shingles will come off just a few times and then it quits, even if the roof has the above issues.
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