I have noticed that today a number of contractors who have used wood shingles on a roof put them directly over plywood.
Years ago I was taught to use lumber and space them apart and that plywood was not acceptable.
What are your thoughts about this?
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You were taught right.
Spheramid Enterprises Architectural Woodworks
" If ya plan to face tomorrow, do it soon"
Putting wood shingles over skip sheathing allows them to breathe.
I looked at a roof in Puget Sound basin that had been on a new house for two years (owner built). They stapled cedar shake directly over felt on top of 1/2" osb. No attic venting at all. I passed on bidding on it. I hate to take jobs where everyone is already strssed out!
After two years the osb was literally falling to pieces.
+++++++++++++++++++++++++++++++++++++
"Doubt is not a pleasant condition, but certainty is absurd." Voltaire
That one was a venting problem - nothing to do with whatever kind of shingle it was
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I can see why you say that. That house is in a location where it is surrounded by fog 9 months a year and is only a hundred feet above the water. It's never dry there. The entire assembly was doomed from inside and out.Now, as to the venting. Don't you think that a shake (more so) or a wood shingle (less so) roof that's over skip sheathing and woven with the felt will, by it's nature, vent considerably?The old frame homes of the midwest that I started working on as young carpenter did not, for the most part, suffer from moisture damage in the attic that wasn't from roof leaks (that's also true here in colorado). I don't really have an explanation of why, although I suppose that the general draftiness and lack of insulation played a part.+++++++++++++++++++++++++++++++++++++"Doubt is not a pleasant condition, but certainty is absurd." Voltaire
When I think of shingles I think of sawn roofing material whereas shakes are split.
yes
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perfections perhaps?
40+sq here. skip sheathing on the old part w/ no felt...why would anyone use felt on skip sheathing???
The rest was cedar breaterized over felt and water and ice shield atthe eaves.
God only knows what my roof would have cost using a roofer.....probably more'n some people houses... Where can I find a man who has forgotten words?I would like to have a word with him.—Chuang-Tzu
They sell all kinda wood roof shingles if you go on the cedar bureau web site. They have cedar shingles that can in fact go directly over plywood I belive but it'll cost ya.
http://www.cedarbureau.org
Edited 9/18/2006 5:26 pm ET by andybuildz
Edited 9/18/2006 5:26 pm ET by andybuildz
I will be putting a cedar shake roof on a log shelter next to a tennis court. All open air. If I skip sheath it(space roof sheathing boards apart) should I bother at all with 30# felt between courses and should I bother with pre-finishing the shingles for durability.
My contention is that if there is no finish and no paper that when the shakes get wet that they will be able to dry thoroughly and will only suffer from surface wear which is something like 1/4" in a century or something.
If the shingles are installed properly it shouldn't leak unless there's a seriously blowing wind in which case hopefully nobody is hanging out trying to play tennis.
I live in a climate that in the summer time is humid and we can get thunderstorms everyday at 2pm for weeks on end.
Am I crazy or shouldn't a roof like this last a long, long time.
I'm not a roofer, but I can give you anecdotal info about felt/no felt:
We bought our house when it was 30 years old with cedar shakes. I know there's lots of definitions of shakes, so I'll tell you that what was on our house were the kind that have a thick (like 2") butt and look like they were split from a log with an axe. The installation was over skip sheathing. On the main house they interwove felt, on the garage they left it off. The garage leaked like a sieve. The main house was mostly dry.
We ended up ripping off that roof, adding solid sheathing, and putting down asphalt. But I live in the desert and a wood roof around here is just plain foolish. It's nice to have dry garage now, too.
shakes or shingles. Most people who say shakes mean shingles. The answer depends on which
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They are medium handsplit shakes 24" long. By the way what exposure should I use for best results? My understanding from the cedar bureau is that a 18" shake should have like a 7 1/2" exposure while a 24" shake can get away with a 10" exposure.
10" exposure if you interweave 30# felt, but 8" exposure if you lay them naked
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Shake liner isn't just to repel water. It also provides a barrier between the (naturally) oiled cedar and the sheathing. Without that barier the oils will wick out of the cedar into the sheathing. This doesn't hurt the sheathing, but shortens the life of the cedar. Same reason we use felt behind cedar siding.
Anyone who's done much remodelling has seen stains on old sheathing that has wicked the oils out of the cedar that is being removed because it has failed or dried out - siding or roofing.
You want to get the most out of your shakes? Lay 24" shakes 7" to the weather. Triple coverage that way. Oh, and the steeper the roof, the better, too/
Want a really great rustic look? Snap lines and hold the TOPS of the shingles to those lines. Looks great, but the roof has to be pretty big for it to look right.
Too bad about the price and quality of cedar shakes any more. Used to be about 50/square when I was young. Had an oldtimer tell me they were cheaper than asphalt 3-tabs here in the Pacific NW in the 60s.Who's the cat that won't cop out, when there's danger all about?
http://www.asmallwoodworkingcompany.com
i have had that problem with cedar shingles(15" long 5-6 inch exposure) for sidwalls not roofs.. bleeding to the face of the shingles,leaving a water stained look ...i believe this has been caused by wet tar paper...when the sun hits tar paper it dries out and lays nice and flat...when its damp out the 15# paper wrinkels ...i have never seen breather boards put behind cedar sidwall shingles..here in the pacific north west ...of corse i havent been around that long either..i want to use that plastic mesh product they make...the stuff holds the shinglesof the paper like a quarter inch.. but the spec homes i side for folks claim the material is not in the budjet
Edited 9/19/2006 1:29 am ET by ringshank
I've never seen furring between sidewalls and siding shingles either, ringshank, but lots of folks here online talk about it like it's a common practice. I've heard it called a "rain screen wall".
When I was talking about the oils wicking from cedar into the sheathing, I meant that felt paper stops that wicking action. I believe it's because the paper is already saturated with more oil than the cedar, but I'm not scientist enough to say for sure.
I just know that when I remove old siding and there's either no paper behind it, or the paper has failed, the sheathing is often stained dark with oils from the cedar - like you said, it almost looks like water stains.
Nice looking siding job. Is that Shakertown panels, or individual shingles, or...?
Where are you in the Pacific NW?Who's the cat that won't cop out, when there's danger all about?
http://www.asmallwoodworkingcompany.com
ive seen that too..water stains on plywood..felt does keep the oil in the shingles but if i hand shingles in the rain and the paper is alittle wet the shingles seem to water stain themself i think ...ive had shingles to that?im in gearhart...on the coastthose are all hand hung one at a time by myself -lost my worker to school-thanks
travis
Oh. I thought this thwead was about wepwacing "Woos" shingles with wots of wittle wingshank nails and wong wadders....
pawdon the intewuption.