warped roof sheathing

arizonahiker · 06-29-2005, 01:11 AM

HI, and thanks to all who take the time to answer this question. I live in the desert southwest(phoenix) and just purchased a home. Recently I noticed a section of my sheathing has warped. It is a small area, between two rafters. I have never seen anything like this before. My question is this, is it possible to replace the small section by cutting out the warped sheathing and replacing it? Would I have to remove a whole layer of shingles across my roof in order to lay a single sheet of underlayment down? Is there a way to apply just a small piece of underlayment down so as to not have any leaks? If so how would I seal it to the adjacent underlayment? The warped part is one foot from the bottom of my roof, over the eve, and the distance of a rafter length(is between the second and third rafter from edge) from the edge of my roof. I would appreciate any ideas of suggestions you may have, as I am planning on repairing it myself and am a newbie at roofing. Thanks again for any help.

jproffer · 06-29-2005, 05:39 PM

First let me say this, at the risk of sounding like a typical contractor...

This is NOT a typical DIY project...however...if you must. :D

Cut on each side. The cut line should be in the center of the rafters. Put blocking at the top and bottom of the hole for a nailer. (at this point you should have rafter/blocking sticking out 3/4" all the way around the hole). Cut the new sheathing, put it in place, and nail every...ohhh...say 8 to 10 inches with 8d nails all around the perimeter. Also renail the old sheathing in places the nails were cut away.

OK that's the easy part(comparatively).....

Now you'll have to remove what's left of the shingles until you get to the nearest whole shingle on both sides, and try to marry the new ones back into the old (after you cover with tar paper of course....your next roofer will thank you when he's tearing off the roof).

HTH, post back any other questions.

BTW, make sure you get a blade that will handle hitting a nail here and there.

exhawk88 · 11-07-2005, 12:17 PM

I have to admit I made two mistakes while doing a roof for my 4ftX8ft shed. First mistake my rafters are 2ft apart instead of 16 inches. Second mistake, I used 11/32in plywood instead of something thicker like 1/2in . I know this will present problems in the future. So before I put up the asphalt shingles, I need your help on how to fix this up to standards before the shingles get put on; hopefully something less dramatic! Thank you!

Mike Swearingen · 11-07-2005, 06:41 PM

I'm not a pro, just a long-time DIYer, but if it were me at this point of your project, I would put a thicker layer of sheathing over that 11/32" thin stuff on 2' centers before tarpapering and shingling, or you will have dipping roofing between the rafters.
I would use at least 1/2" over the 11/32" to give you over 3/4" for the 2' centers. It should hold up even walking on it with that.
(Maybe a pro has a better idea.)
Good Luck!
Mike

jproffer · 11-07-2005, 09:14 PM

Quote:

I would put a thicker layer of sheathing over that 11/32" thin stuff on 2' centers before tarpapering and shingling, or you will have dipping roofing between the rafters.

That's less than 3/8"

...with that you'll have dipping roofERS between the rafters. :D

Definately add more. 1/2" would be fine.

Mike Swearingen · 11-08-2005, 02:24 PM

P.S.
Stagger the sheathing joints differently than the bottom layer.
Mike

exhawk88 · 11-08-2005, 05:27 PM

Gentlement, Thank you for your responses. Will put 1/2" layer of plywood on top of the existing one this weekend.

Teetorbilt · 11-08-2005, 06:33 PM

As mean as this may sound, I'd tear off the exsisting and go 5/8-3/4". Two thin sheets do not add up to one thicker sheet without being bonded together.

Ever see someone rip a phonebook in half? It works on the same principal. Glue all of the pages together and it's going to take a chainsaw to get through it.

Mike Swearingen · 11-09-2005, 06:06 PM

Could use Liquid Nails between the layers.
Mike

exhawk88 · 11-09-2005, 07:19 PM

Make sense...I will go with liquid nails between the layers. Thanks again!

AaronB · 11-09-2005, 08:32 PM

Quote:

Originally Posted by Teetorbilt

As mean as this may sound, I'd tear off the exsisting and go 5/8-3/4". Two thin sheets do not add up to one thicker sheet without being bonded together.

Ever see someone rip a phonebook in half? It works on the same principal. Glue all of the pages together and it's going to take a chainsaw to get through it.

I disagree, teetor. We have put 3/8" over 3/8 " and the stuff is as storng as 3/4" as long as you break the seams dimensionally both ways. This means if your roof deck was started with a full sheet, then I would start the second layer with 1/4 sheet, ripping the full sheet in half longwise and then half the lenth of the ripped sheet.

exhawk88 · 11-15-2005, 11:01 PM

Well, I took Mr. Scurlock's advice on putting 3/8 over 3/8 and Mr. Swearingen's advice on using liquid nails between the sheets. It felt so strong as I walked on it. (1/2 would've been "overkilled" in my opinion, but then again what do I know as a first time DIY roofer). I am happy with the end result though and thank you all again for your input and suggestions.

AaronB · 11-16-2005, 05:46 AM

Did you break all seams as I reccomended? I think liquid nails is overkill, but hey, I am just a roofer. LOL :D

JustaFramer · 11-17-2005, 01:53 AM

Quote:

Originally Posted by AaronB

Did you break all seams as I reccomended? I think liquid nails is overkill, but hey, I am just a roofer. LOL :D

Yeah and I am justa(roof)framer.:p