A couple of roofing questions. We appear to have 30 year comp shingles on our roof, that are about 15 years old. We’ve learned that the shingles along three sides of the perimeter of the roof have cupped, practically creating its own rain gutter. Not by design, but to just give a visual image. This appears to have lead to water leaking under the shingles getting under the drip edge and having rotted out some of the back side of the facia board. Any ideas of why these shingles would have cupped. Heavy winds are the only things I could think of, yet its only on the perimeter of the roof.
We had a roofer take a look at the situation. He feels that the there is enough of this cupping, that we should consider a new roof, which is fine. Since most of the perimeter has cupped, he is suggesting that we add 1/2″ plywood on top of the existing 3/8″ to give the nails better bite reducing the chance of the shingles cupping or having shingle getting blown off in the wind (which there is some evidence of.
For the roofers out there, does this not seem like overkill to have the sheathing this thick, or does this seem reasonable.
The house is a 2 story (mid-70’s house) with a stick build roof with 2×4 rafters set 16’oc. I’m also worried about the weight of the extra layer of ply, but not sure if this is really a concern.
Thanks for any advise,
Tark
Replies
this is a bump.
However it might not be a bad idea to add sheathing. I don't like to get on many roofs with just 3/8 ply. We tend to use 7/16 or 5/8.
Webby
3/8" is way underkill. You need sheathing.
Since you have this roof for only 15 years on a 40 year old house, this might not be the only layer of shingles on it and that ould account for the strange observations you report.
It is unique enough that I'd want to see a picture first before commenting further
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Hi Piffin,Thanks for responding. A picture is attached. The current roof is the only layer. The house in question was my late parents, and they have owned it since the house was built. The original roof was a tar & gravel and my roofer was explaining to me that the sheathing would normally be 3/8" for a tar & gravel, so I guess its an educated guess on his part. The original tar & gravel roof was replaced with a comp shingle, which suffered wind damage many years ago. After insurance paid-out, we had it stripped off and replaced with the current roof. Any additional thoughts on what could have caused this cupping would be greatly appreciated. Also, based on your earlier comment, it sounds like 3/8" is undersized as far as sheathing goes. Would you agree that adding an additional 1/2" would be the way to go. Should I be concerned about the additional weight.Thanks again,Tark
hey piffin,
the shingles have reached their life span. Are you in hot climate? If so, that probably didn't help, but take the previous advise and use a minimum of 1/2" decking.
Even though you can probably re-roof over the existing shingles, I believe it would be best to tear them off, cover the old deck with new OSB or Plywood, then follow local codes which will probably specify Ice shield at least from eaves to beyond the walls, then roofing felt and you might consider a ridge vent while you're at it to keep the next shingles from cupping longer. pay for the heavier shingle, that'll be guaranteed for 25 to 30 years. If you wind up deciding to sell, it will be a selling point. Asphalt has gone up this year, but don't go cheap. Your roof is what protects the rest of the house, including the paint.
good luck.
tark
after looking at the picture it seems to me that what you are calling cupping of the shingles is nails lifting from the deck, at least in the field of the roof.
The cupping you're seeing along the edge of the roof could be the connection between the sheeting and the facia, facia set to high at that point causing the gutter effect. Vince Carbone
Riverside Builders
Franklin,NY
good call Vince!
Oh, my, I never looked at the picture before--you are right! He needs to strip everything off to see what he's got and re-set the fascia. I'll bet there is lots of rot everywhere.
The idea I got from the first post was that he wanted to add another layer (this time 3/8") of sheathing over the existing. I think he will find that the existing sheathing is pretty much shot, especially down toward the eves and he should take it off and start over. Like you said, use Water and Ice Shield at eaves, with proper drip edge and so on.
The facia on one side will need to be replaced due to rot. Everywhere else it appears to be fine and intact. I'll know more about whether the facia sits proud of the roof and the condition of the sheathing when they strip it off. There is a drip edge all around and the existing shingles extend beyond it by 3/4" to an 1" beyond it. I'll let everyone know, how this turns out in a couple of weeks.Thanks,Tark
Edited 8/8/2009 10:53 am by Tark
If you add sheeting, you may not have to move the fascia if its to high, the extra ply may stop the problem at the eaves.
Tark '
it seems a shame to have to tear off the roof, but 3/8 ply isn't enough in my mind. Adding 1/2 on top of the 3/8 after striping would be a good thing.
The shingles in the picture don't look that bad. Vince Carbone
Riverside Builders
Franklin,NY
"The shingles in the picture don't look that bad."Same to me. I see no sign of excessive wear , just a bad install at the edge. i couldd replace the eave all along a lot less expensive than whole roof.Only problem with that is the new shingle colour match might not be good
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" He needs to strip everything off to see"Why everything? The only problem appears to be at the eave. I'd just remove the bottom 3-4 courses of shingles
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Thanks Bobalu.We live in a town just outside of San Francisco, where we're known for our fog, if anything else. We're lucky to get past 70 degrees for more then a couple of days in a row.We plan on replacing with a 40 year shingle and will have the existing shingles stripped. I'm glad to hear that the additional 1/2" ply is a good idea. I guess of all these years of having the house, I'd never heard of adding another layer of ply, so it surprised me.
Edited 8/8/2009 10:50 am by Tark
Tark,Just be sure to check my advise out with a competent roofer. I'm not sure of these blogs being any better than just suggestions, but out of them comes a variety of good and bad ideas and opinions. Usually when there is spot damage to roof decking, the roofer will patch it to the nearest rafter, attempting to keep the thickness consistent to the original. Is the deck spongy when it's walked on? If so, the previous 3/8 ply decking may be starting to delaminate. In that case a further discussion and examination with a few roofers i.s recommended.Removal of the roof deck is a messy affair for the house interior and avoided if possible.
Good luck
Bobalu,I see you are new to this forum.
Welome in.I have a tip for you on how this ine works. When you reply to a post, your reply defaults to the person whose post it si that you click reply on. If you want to adress it to the person who stare thread or another person who has participated in the thread, then look near the top of the reply window in the light blue bar where your screen will say
from: bobalu
To: ___________That blank I show is a dropdown menu containing the names of all who have joined the thread so you can select which one you want to point your comments at.I only mention thoiss bewause this is the second thread where I notice you commenting to mew as though I were to OP ( original poster) whih I am not.So much for housekeeping. Have fun. BT is a great place to hang
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Hey Piffin,
Thanks for the tip. I hope I did this correctly. The older I get, the worse I get with these things. I usually don't have the time for blogging, but I may be getting hooked. I've been amazed on the diversity of opinions on the same subject, which shows how work can be done well to poorly. Now there are so many new materials that if you're not in the biz, you most likely are not aware of and between blogs and site like this are a great aid.
Thanks again,
Bob
Sparta, NJ & Pasadena ,Ca
Correct.This is what is known as a forum, a place where multiple personalities can discuss varieties of solutions and argue them out before their peers.A blog however is a weB LOG, where one person generally - say you for instance, keeps a daily or weekly log of what s/he is doing, and occcasionally others can make commentsmy signature liune below is beause I compare this Forum to the oldest universities such as first came into being as when Paris was a young city and Europe was awakewning out of the dark ages and travelors brought, sought, and shared knowledge while crossing the land from Spain, England, Riussia, Rome and Greece, as well as the more enlightened lands of the Moors to the south
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Thanks for that clarification and philosophy. Unfortunately, we can't have the personal interaction of those days.
That's why we have Breaktime.there really are all sorts drawn to this forum because of the word FINE in FHB.
We have doctors, lawyers, architects, politicians, tradesment and even a rocket scientist or two
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I'm impressed. Lawyers?
OK this one is 300pix wide low res.
I should be in Malibu now.
Later,
You've got it nowReally cute bungalow you have
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Thanks. A lot of work, but I can't say it isn't fun. It's a MinMansion.
The shingles are not worn out and cupping. That looks like a bad metaledge install to me. Id so, I has been that way since the shingles were put on.
Would need to peek down over the edge to know. I wonder if they removed the old gravel gaurd roof edge when cahnging to shingles and put a drip edge on. maybe not, but if they did, it was a lousey job of it.Could also have somewhat to doi with poor fascia holding it up.
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My roofer also provided the option of just changing the shingles around the perimeter of the house, but was suggesting against it, mostly since the repair involved most of the perimeter and matching the shingles would be a challenge. I'd hate to have to change the whole roof if a repair would let it get by for another 10 years or so. I think I'll ask for him to present pricing on either option and discuss more indepth the idea of just repairing the damage areas. Thankfully, the damaged facia board is only on one side of the house. I'll let everyone know how it goes.Thanks again,Tark
So just to let everyone know how this is all going so far. Roofers came by to do the repair this morning. They tore off the first 2' from the edge of the roof and came upon what the previous roofer did. It appears that the roofers did not strip off the tar & gravel off of the last 1' around the perimeter, which was creating this hump and causing the cupping of the shingles. The roofers here now indicate that taking off the remaining tar & gravel would be very difficult. Since it is all the way around the perimeter, its been recommended that we should just go for the new roof.
I'm tending to agree.They would put new sheathing down on top of everything so they will have a flat surface to work on, plus we've determined that the old sheathing is in fact 3/8".The one question, I'm not getting is since the previous roofer was able to take off all the old tar & gravel off of the roof, why these roofers could not take the remaining tar & gravel off the perimeter. I was not understanding their answer, other then it was difficult.Anyways, just wanted to let everyone know.Tark
Tark,
it seems like they're determined to sell you a new roof.
there could be a reason why the tar and gravel wasn't removed to begin with but I don't get it.
Maybe get up there and try to remove some yourself and see. Vince Carbone
Riverside Builders
Franklin,NY
I did get up on the roof. It appears that there is a lip at the edge of the roof (as someone else suggested in one of the earlier comments that there could be a gravel guard) The previous roofers left the tar in place to built up the edge to compensate for this lip. Unfortunately, this build up has an uneven transition and sort of flattens the edge of the roof, decreasing the pitch some. They only torn off one side of the roof, but its easy to see this transition and decreased pitch around the whole perimeter of the house. his particular roofer has been great to our family for several years, although we did not know him yet when this roof was last replaced. He is one of those guys that will come and take care of a roof leak in the middle of a rain storm the same day I'd call. He once took care of a roof leak we had (on another house) of which he had never done any work previously. I could not get him to take my money. Needless to day, a couple of years later, he did change out that roof.I do feel like I may being getting sold this roof prematurely, maybe the economy has hit him too and he has to act accordingly. But he's always been good to us and I feel confident that he will do a great job. Tark