6 pitch roof in North Carolina – trusses on 2′ center – 1/2″ osb sheathing
24×40′ building to be used as a Karate studio
Would you recommend for or against roll roofing?
Thanks,
Roger
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Replies
6/12? Against roll, roofing shingles of course!
If money is the problem and appearance not an issue go ahead and roll.
Why not corrugated sheet metal?
doable if all you want is cheap and do't care about apearance.
But not a good choice. The 1/2 osb at 24" oc is a biggggg cconcern
Flex there break thru the materials. that is the first place it will leak
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Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
the half which is really seven sixteenths...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
or it could be the real 1/2!
if yur gonna cut one corner...
cut 'em all....
we seen it over and over again....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
I am sure 5/8 is better, but I have installed acres of 1/2 osb on 24 OC ond have only seen sagging once that I can remember. We rarly use H clips. Just doesn't seem to be a problem. And the osb is stamped as being rated for 24 centers.
Now don't get me wrong, I don't love or really even like osb much (lots of other faults), but 1/2 osb can make a perfectly fine reasonbly priced roof deck.
and I have nailed shingles onto acres of half inch. can't tell you how many times I have seen so much flex at that joint that it breaks the shingle there
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
The roof deck is going to sag out between trusses. This is a cheap design that will not last many years. The sheathing should be 5/8" plywood for that truss spacing no matter what code permits.
Roof covering? Don't put anything on there rated to last for more than 10 or 15 years; the roof itself probably won't last that long....
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
Done all the time as long as you use clips that roof will not sag!
Done all the time as long as you use clips that roof will not sag!
Bro, I'm (painfully!) aware that it's done all the time but that doesn't make it good--it just makes it common.
And H-clips aren't going to do a dang thing to prevent sagging between trusses; at the most they could help reduce the kind of damage Piffin's talking about when nailing on shingles at sheet joints.
But ½" roof sheathing over 24" OC supports will sag over time, whether it's OSB or even plywood. Especially on a relatively low-slope roof like a 6/12. (I see that all the time.) After a few years, roofs that were built to that spec get that 'scalloped' look to them, and when you walk 'em you feel it bounce.
So, my advice to the OP was to keep the roof covering in common with the sheathing & framing: light and cheap. Putting a heavy load of top-quality 40- or 50-year 3-tabs on such a roof is not gonna help things....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I am going to respectivly disagree.
Where he lives he doesn't have to deal with large snow load.
We have used 1/2 ply and 7/16 and 1/2 osb around here fore years without the sag that you say are common. We have a large snow load around here and I don't know why it sags in your part of the country. I forgot to mention that 2' center is the norm.
Now if you had said 3/8 ply, which was common in the 50-60's I would agree, not 1/2 ply or OSB.
I'll agree he probably has a fair bit less snow than either you or I, LOL. And I will freely admit I am very conservative on this sort of thing. I won't put OSB on a house roof (or floor); only plywood or solid planks. (OSB is for walls IMO; it's fairly good at resisting racking, but it can't take perpendicular thrust the way longer-grained sheathing can.)
Also, I won't do ½" sheathing on a roof under 12/12 unless the rafters/trusses are on 16" centers (which is uncommon here); anything shallower than that I use 5/8" ply, and for small roofs like sheds and bump-outs, I'll often use 1x planks.
The damned thing is, last time I bothered to check the NBCC allowed 9.5mm Beaver Barf over 24"OC trusses/rafters. Yeee-ick. For a code that usually gets it right, they sure got it wrong there. Makes guys who put on 7/16 feel virtuous by comparison....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Beever board is acceptable?
I won't go that far, for sure!
Try that deckin' ply that piffen talks about, good stuff!!
Ya see? We always wind up agreeing on something....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Now if the boys in the tavern were this easy>G<
Yer callin' me 'easy'??
I think I resemble that....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I know I am!!!!!!!!!
20 yr 3 tab shingles. Much more reliable and long lasting.
They still sell 20 yr shingles?
Yup , but they call them 30 year !!
Took the words right out of my mouth
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
haven't seen any 3 tabs in couple of years.
haven't seen any 3 tabs in couple of years.
I was talking with my shingle supplier today (we've been having trouble getting any special order shingles lately - if it ain't in stock, then you ain't getting any) and he said he had lots of 3 tabs on the yard - the same ones he's had for a long time. I asked him what percentage of the total sold was 3 tabs and he guessed 10% at most. We've put some on lately, but just on addition roofs or repairs to existing.View Image
They still sell 20 yr shingles?
http://www.gaf.com/General/GafMain.asp?Silo=RES1&WS=GAF&App=ROOF&Force=shingle-lines.asp
Yup, they're still around. Sentinel, lower left.
Edited 8/28/2008 7:23 pm by Hudson Valley Carpenter
against
In today's price structure, it would be a very poor choice to go with roll.
BTW, others may be able to concur that there are not many on BT cheaper than me<G>, so take the following as coming from a real cheapskate.
Like others said, 3 tab, no question. I'd even carry it farther and say I'll probably never install roll again in my life except maybe on a shed only to use up existing stock.
Did put roll roofing on my cabin (see FHB, NOv 1990, Great Moments) in 1980, putting 3 tab on now after 28 years, 7/12 slope.
Back then I had to build the whole cabin for under $500 (or pay another $500 in permits) and roll was the only way to meet that cost goal as it was just $7 sq then, and 3 tab was $18, for 6 squares that was a 13% difference against the entire building cost.
August 27, 2008 (just priced it yesterday) the roll is way up to $39 a sq here, cheap flat 3-tab (3 bundles per sq) is $48 sq, almost no savings. If you install the roll right in 50% selvage vs leak prone 2 inch lap, roll costs MORE than 3 tab. Cabin will go with 4 bundles per sq architectural shingle ($59 sq) this time. You are at only 10 squares, cost differential in PNW is only $200 going with architectural 3 tab, only $90 with flat 3-tab.
Limited install experience compared to others, only having installed about 50 squares of 3-tab and about the same amount of roll (on 2/12 slope) over the years, but my experience is that it is less labor to install the 3-tab than the roll, first 2 squares pays for your pneumatic nailer. I'd guess it would be at least a 4 hour longer job doing the roll, so at $30-hr, flat 3-tab is cheaper than roll! If you do the roll right and 15" selvage install it, 3-tab is much cheaper.
The cabin has a porch with 2/12 slope, actually am going to put metal on that part vs roll even though there are 2 unused rolls stacked there just because the labor is so much less (DIY time savings)