Having been building custom homes for 20 plus years, I would appreciate other professionals opinions regarding roof sheeting. At the start of my career, I used plywood exclusively. When O.S.B. became more popular (Early to mid 90s), I switched to 5/8″ O.S.B. and have been happily using it since. I especially like the advantech sheeting and would recommend it to anyone. It falls flat on the rafters or trusses with a resounding thud, unlike the CDX or similar roof ply. It holds a nail great and you can rest assured it is square. Ice and Water sticks to it too well, sometimes. The only negative is that when stapling felt down, staples (only DuoFast) have a more difficult time sticking. I am working on a custom home plan for a couple and the owner doesn’t think putting 5/8″ on the roof is a good investment, thinks 1/2″ is good enough. Any input on your part, for or against will be appreciated. Thank You in advance.
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My advice is to not use staples for holding felt down.
I prefer a button nail either hand or pnumatically driven .
I also prefer matched boards for roof sheathing not osb or plywood.
What is the pitch of the roof; what is the rafter spacing; what is the roof snow-load in that region; and what will the final roofing material be?
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
(Typically 12 pitch as I do many custom log homes.) On this project 6 pitch with some 12 pitch at front entry and rear gable. Snow load is 50#, and I will be laying 30 year certainteed dimm. shingles.Vented soffits and cont. Shinglevent ridge vent
If the rafters are on 24" centers, use 5/8" everywhere.
If the rafters are on 16" centers, you may use ¨ö" on the 12:12 pitch areas, but not the 6:12. Especially if you insist on using Beaver Barf instead of boards or plywood.
This is (as you asked) my opinion; it is substantially 'overcode'.
NB--Unless the house is huge, the cost difference between ¨ö" and ¨ý" is negligible.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Thanks for Your opinion. I felt the same way for a long time. Having used the Advantech O.S.B. I can't say that I would ever go back to board or ply. Advantech is the same mat. as the O.S.B. found in TJI floor joists, it is super strong and densely pressed. As far as cost, it is more than Ply and I would assume board unless you bought rough sawn. I'll see if I can post some photos of some SUPER flat (plane wise) roofs. Maybe you should give it a try.
"Advantech is the same mat. as the O.S.B. found in TJI floor joists, it is super strong and densely pressed. As far as cost, it is more than Ply"Similar, but not the same. Advantec is made by Huber. I am an Advantec fan too. it also uses better resins than typical OSB. And some wood I-joists have ply, not OSB webs.Cost comparisons vary. as a general rule, I get advantec for same price as CDXply, but it varies according to demand and when certain sheet goods plants get shut down for maintenence or to try creating false supply shortages to bump pricing.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
As far as cost, it is more than Ply and I would assume board unless you bought rough sawn. I'll see if I can post some photos of some SUPER flat (plane wise) roofs. Maybe you should give it a try.
I don't call me 'Dinosaur' for nothing, Deck. ;-)
Seriously, I don't see any advantage to paying more for an OSB product than for solid wood or plywood. I prefer to use 1x boards--often rough-sawn hemlock--on smaller roofs, but will usually cave in and use plywood on bigger projects because the time saved over a couple of thousand SF (as opposed to a couple of hundred SF on an outbuilding) starts to become noticeable on the bottom line.
OSBs have been on the market for only about a third of the time that plywood has been in use--so the long-term viability of the product is still unknown--but the difference in sag resistance between plywood and OSB is very palpable and is visible over the short term. It has nothing to do with the 'better' resins used in proprietary products such as Advantec; it has to do with the length of uninterrupted wood fibre present in the sheet. Plywood has full-length fibres; OSB does not.
Sure, OSB lies flat as a pancake right off the stack...but after it's been up there through a couple of winters, it doesn't. It sags visibly between supports, especially if somebody has cheaped out on sheathing thickness and/or rafter spacing. Ply may not lie as flat on the rafters as brand-new OSB before you nail it down, but it won't sag between supports after having spent some time sitting under a couple of feet of snow.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Aren't you supposed to be boiling sap?
Aren't you supposed to be boiling sap?
The 'run' has slowed down to a trickle; it's not getting cold enough at night right now. I haven't pulled my buckets, tho; you never know what Mama Nature has in store this time of year.
So far, it's been a very good run and I've already produced 1½ times my record harvest of a few years ago. There is enough sap sitting in the chaudières at the moment to make another small batch of syrup, and we'll probably boil that on the weekend. I haven't planned a B-day party for Ryan this year; too disorganised what with the trip to the Gaspé and all the rest of it. Maybe we'll just boil syrup and I'll take him out to a cabane for supper that night with Felix and Fanny if they're not away for the weekend.
Right now it's raining; tomorrow I gotta go jack up one end of a 40' house trailer that's sinking into the mud....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Saturday they are calling for 25 and Sunday calling for 26 celcius.
Yeah, I heard that. Well, the ice is off the lake--mostly--but I don't feel quite ready for a 5am 'splash' yet.
I didn't check the buckets when I got home tonight--spent all afternoon crawling around in the mud under a 40' house trailer--but it didn't freeze up here last night so I'd be surprised if the trees were running today in spite of the +10º daytime temp. Another couple of days of above-freezing nights and that'll put an end to the run for the summer.
Did you know you can make 'autumn syrup' during that part of the fall when it dips below 0º at night but gets up to +15º or so during the day? A commercial syrup producer told me it's not worth his trouble but it does work and doesn't harm the trees.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
I agree I can tell every house with a 7/16 osb roof. Looks like a lake on a windy day.I have made maple syurp from Manitoba Maples in SK. My aunt from Owen Sound enjoyed it.
"little different but Good". She also sent out the spyles.
http://www.statcan.gc.ca/pub/96-328-m/2004032/4194001-eng.pdf
This is a pdf from StatsCan about tapping Manitoba maples. It's only 112kb.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
"the ice is off the lake--mostly--"On one of my jobs here we had the remnants of a snow drift left in the shade of a hedge. Plan to start digging foundation later this week. hope the ice is gone down under the sod.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
hope the ice is gone down under the sod.
Having spent yesterday crawling around under a 40' house trailer in 2" of surface mud over 2 feet of solid ice so I could jack up the deck to a quasi-level state, I would tend to be sceptical on that point. I had to use a pick to bust out chunks of ice-n-mud so I could drop Dek-blocks under there to sit the Lally columns on. (All this so the R-E agent can show the place next week, duh. It'll all have to be re-done properly after the ground thaws, say in about a month.)
Best suggestion I can give you is to lay sheets of heavy black poly sheeting over the area you want to thaw, and pray for sunshine.
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
"Ply may not lie as flat on the rafters as brand-new OSB before you nail it down, but it won't sag between supports after having spent some time sitting under a couple of feet of snow."Depends a lot on the thickness of ply you use. The way plywood delaminates so much the past 10-20 years conmpared to what it once was, I don't care to use plywood at allifthe choice is between it and Advantec. But I will absolutely not use normal OSB on a roof. There is THAT much difference between OSB and Advantec.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
How do you feel about board sheathing? Can you get decent 1x roofdecking anymore out your way?
A lot of the older places up here were sheathed in rough hem up until shortly before the war; they tend to stand up to sag and weather damage better than most anything else I see. Places built after the war up until about the mid-60s were mostly done with T&G spruce but a fair amount of plywood was also used. Since then, it's all ply until the last 10-15 years when the Beaver Barf came into vogue. Can't even buy T&G spruce anymore.
When I'm working alone--almost always on smaller jobs--it makes life soooo much more pleasant not to be wrestling 4x8 sheets up a ladder in the wind....
Dinosaur
How now, Mighty Sauron, that thou art not broughtlow by this? For thine evil pales before that whichfoolish men call Justice....
Use a fair amt of it on older places on patch and repair, but anything new or large the labour cost will eat you alive. Got no problem with quality.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piff -
"...compared to what it once was..." ?
I took apart a long narrow house last summer. The front half was shiplap sheathing built in the late 40's, the back half was plywood built in about the late 50's. The only evidence that the plies in the plywood were at one time glued together was that it was all nailed neatly to the framing. Not one square inch of any ply was stuck to another. It was all loose plies, walls and roof (floor was shiplap throughout). Weird.
That's something I've always wondered about, how long does glue last? I try to build for the long term but this has always nagged at the back of my thoughts - at the bottom of it all is glue holding it together. When the glue goes, so goes the house, especially if you're using engineered lumber.
I kinda hoped glues would be getting better. - r
When it is consistently that bad, I wonder if they might have used seconds or it it was the fire-resistant stuff from the late seventies. the industry found out too late that heat would make it break down. Mostly this seen in roof sheathing where attics got hot enough to make it happen
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Having walked on those roofs years after installation, I wouldn't use the 1/2". It's amazing that people are hiring you to build a custom house, but they want to cut materials back to what would go on a spec house in a development.
If this is the kind of micromanaging they are doing now, good luck later.
Don K.
EJG Homes Renovations - New Construction - Rentals
Well said. To most of my past customers money wasn't an issue but a consideration. Now with the state of the state, customers try to cut the wrong corners and I'm not much of a corner cutter. They will take the $2000 light fixture and cut the Timberstrands out of the Kitchen walls, or worse, take 5/8" of the roof system and throw down 1/2".I have always been a serious framer, with structure being the king. Quality in, Quality out.
"If this is the kind of micromanaging they are doing now, good luck later."
Good point. Could be a tough row to hoe.
"Preach the Gospel at all times; if necessary, use words." - St. Francis of Assisi
No, I didn't vote for him; but he IS my president. I pray for the his safety, and the safety of his family every day. And I pray that he makes wise decisions.
Around here custom builders only use OSB if they can put it down and have the shingles on in one day..... meaning never.
If it gets wet you can see every seam telegraph through the shingles. Not a look most are after.
I use the 5/8" for that specific reason. In my area the "hacks" will throw 7/16" down if they can get away with it. Full subdivisions with "Roof Bones" showing and vinyl "box poppers ' is definitely not a pretty sight. It's a waste of (questionable) lumber. A lot of that material could have been great backing material or MUDD cover. HACKS DEFINITION: Builder/Developers who flood the market with 1600 to 1800 sq. ft. 2 month build time junk that sells "on the lot" for $149,900.................
deck.... we used to use 1/2 " cdx and clips with 16" spacing and...
5/8 with clips if the spacing was 24"
now , with wind code at 110 mph,
we use only 5/8 T&G Advantech ( no clips )
and we can eliminate a lot of edge and perimter blocking we would otherwise have to use to comply with the 110 mph specs
we don't use staples , we use bostich plastic cap/stapleMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
...and the owner doesn't think putting 5/8" on the roof is a good investment, thinks 1/2" is good enough.
Reading this topic is an education for me, having never done the large jobs. But I find it curious the customer would/could dictate what thickness roof deck sheething to use. Is that common?
If so, how much do they save? If it's just a hundred dollars over the cost of a new home, seems kind of trivial.
~ Ted W ~
Cheap Tools! - MyToolbox.net
Meet me at House & Builder!
Edited 4/21/2009 1:10 am by Ted W.
why use staples when cap nails do a much better job? Rooftopgaurd is better than felt too.
As for whether to use 5/8" or 1/2", it depends on your load requirements.
Green Bay ( thanks for filling out your profile, BTW) is likely to see some snow, but I don't know how much. You also don't say whether you are framing with trusses 24" OC or stick framing at 16"oc which would make all the difference in the world for my decision.
It is really not the owner's decision unless they know more than you do re structural issues. Their part is to inform you on the cosmetic decisions, like type and colour of shingle, and whether they want the sheathing to sag between frame members.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Tell the customer that you are not in the business of building economy homes. If that is what he wants he should look for a different guy. if he wants a quality home then he should trust your advice.
I refuse to accept that there are limitations to what we can accomplish. Pete Draganic
Take life as a test and shoot for a better score each day. Matt Garcia