Redoing an old barn roof, i.e. stripping down to 1×6 under old cedar shakes. Can I get by with 1/4 ply or 7/16 osb over the top ? It is not a full gambrel roof but there is a “half round” pitch in middle of roof.
Edited 4/27/2007 6:19 pm by karteberry
Replies
What are you putting down on top of the new plywood?
You've been aruond here long enough to know that you need to give us all the necessary info to get a straight answer. So 40 lashes with a wet noodle for you, followed by a half hour sitting in the corner.
(-:
Sorry, I have, you are right. I stand corrected. 40 year Arch. Shingles.
If it were me, I'd use 7/16 OSB. I like having plenty of stuff for the nails to bite into. I know most of your nails would hit the 1X boards. But some of the nails would also fall between them.Can't give you a real solid reason other than personal preference, though.
The beginning of wisdom is silence.
why not just play it safe and use 1/2 OSB? That's way more commonly available, so the addition thickness would only have a minimal price difference
1/2 OSB around these parts (CT) is less than $6 per sheet, too.
Justin Fink - FHB Editorial
Your Friendly Neighborhood Remodelerator
Yer meaning 7/16" OSB.
karteberry,
For something the size of a barn the 7/16" can be discounted at a bigbox for an additioal 10 to 20% off and maybe put that money towards a delivery.
I think you'd do better going with a 30year archy shingle than the 40year.
Something barn size I'd definitely want a rooftop delivery for the shingles and devise a pullysystem to get the osb up there.
You going to tie off to the peak with a harness?
However, if one designs to construct a dwelling-house, it behooves him to exercise a little Yankee shrewdness, lest after all he find himself in a workhouse, a labyrinth without a clue, a museum, an almshouse, a prison, or a splendid mausoleum instead.
Parolee # 53804
<< Yer meaning 7/16" OSB. >>
I feel my hairs being split :)
Thanks for keeping my accurate, Rez.Justin Fink - FHB Editorial
Your Friendly Neighborhood Remodelerator
Just aim ta please. 1/2" is substantially higher for that 1/16" inch.
Yep, my first thought was a metal roof but then again we don't know the overall shape of the roof and any bow and sway would need remedied via shimming or whatever.
OSB and archys is pretty straight foward and can hide a multitude of sins.
However, if one designs to construct a dwelling-house, it behooves him to exercise a little Yankee shrewdness, lest after all he find himself in a workhouse, a labyrinth without a clue, a museum, an almshouse, a prison, or a splendid mausoleum instead.
Parolee # 53804
You mention half round roof. Or something to that effect. On roofs like that where it looks like a barrel split in half I have used 3/8" plywood with good success.
It bends around the curve of the roof nicely. I tried 7/16's it worked but was very stiff. One sheet snapped.
I also had to repair some rotted sheeting that was 1x material. Two layers of 3/8's filled it perfect.
EDIT: sorry Rez meant for the OP
Edited 4/27/2007 7:35 pm ET by Stilletto
I'll get some pictures and post so you can look at them. That's my big concern is 7/16 won't "give" or "bend" enough which is why I considered 3/8.
I had a project some time ago that required 1/4" OSB for something... had something to do with matching what was already up there. Although the 1/4" was available at the big box it was significantly more expensive than the 7/16" presumably because the 1/4" is a low volume product or whatever. BTW - right now 7/16" is at the rock bottom price of ~$5 a sheet.
I think we do need the pic though to get some kind of idea of what kind of radius on the bends you are talking about. If the radiuses are more than a little I might consider doing the flat parts with 7/16 OSB and the curved parts with 3/8 ply or 2 layers of 1/4" ply. Actually they even have 1/4" plywood that is made to be flexible - forget the name - "flex ply" or something like that?
if you are going to split hairs at least do it accurately, the osb that is sold in this country is measured in 32's, and it is written as such (stamped) right on the sheets.
the 3/4 is actually 23/32, 1/2 is 15/32, etc etc. they are now getting us for the additional 32nd of an inch in the standard dimensional sheet lumber. i do not know how long its been like this, but its been a while.
Segundo -
Sheet material thickness went metric years ago when the manufacturing went overseas. The thicknesses are actually in mm, and that causes that annoying 1/32" discrepancy when we try to convert to english units.
Even those aren't always consistent. I've bought several sheets of 3/4" cabinet grade plywood over the past few months that actually measured 11/16" instead of 23/32". Luckily, I always run some test cuts with my stacked dado cutter or I would have run some sloppy dados in some expensive material.
I might stand corrected,
seeing by consumer viewed signage it's still sold as 7/16 and 1/2.
be a hair
However, if one designs to construct a dwelling-house, it behooves him to exercise a little Yankee shrewdness, lest after all he find himself in a workhouse, a labyrinth without a clue, a museum, an almshouse, a prison, or a splendid mausoleum instead.
Parolee # 53804
I didn't realise that osb came in 3/8" and 1/4" variety. If I was a purist, I would tell you plywood,but I am a sure 1/2" osb will do just fine.
Greg in Connecticut
3/8" to 1/2"
The 1/4" would be a waste of time
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That 1x6 is called skip sheathing and it's spacing will be important to determine the thickness of the OSB. I wouldn't use 1/4" unless the skip sheathing is very close together (<2" apart). For anything wider, I would go with the 7/16".
Unless you're a total masochist, get an "on-the-roof" delivery of the sheathing and shingles. About 45 years ago, I humped bundles of three tabs and roofing paper up a ladder while my Dad and Grandad laid the roofing. That cured me for life and I haven't done it again!!!
If you're doing a real barn, why not use good old roofing tin? It goes on pretty easily and is actually easier to handle. An added benefit is that it makes rainy day naps a sheer delight. Any time I'm in the barn when it's raining, I'm giving serious consideration to crawling up on the hay bales and taking a little siesta!! - lol
I was thinking what Dave was thinking, why not just go to metal and be done with it? You should be able to fasten the metal right to the skip boards, 'less someone else here disagrees?Would go a lot faster and last a lot longer. Also, with the metal, I'd think having one person on the roof with another down below to tie on with a rope and the top person could hoist up by hand, the sheets would be light enough. Although I wouldn't want to do it on a windy day :) And you should tie off.
I'm going with 7/16 osb. The reason for not using metal is simply the customer considered, and decided he wanted shingles. Boss, that's the reason I was leary of 1/4 ply, because of "catching" the nails. Thanks.