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I found this on the cedar bureau site.
I’ve seen lots of people around here going right over the plywood and felt paper and the cedar bureau even shows its OK in low humidity areas but it goes against all I’ve heard in the past.
I’ll be doing about 40 sq over ply and 30# felt over the additions I just finished and after I rip the existing roof I’ll be going over skip sheathing.
I know I can add 1×4 vertically and then horizontally over that before roofing but I’m not sure its necessary because this isn’t a high humidity climate here in NY.
Anyone have any definate practical facts about the plywood areas?
Thanks
andy
“My life is my practice”
Replies
>> ... because this isn't a high humidity climate here in NY.
Compared to Mombassa maybe not. Compared to Denver it is definitely a high humidity climate. Remind me again how far your house is from the ocean.
That is for TREATED shingles. What are they treated with and for what purpose?
For the plywood areas, use a product called Cedar Breather (i think). It is a mesh product that keeps the cedar from coming into contact with the roof surface. Skip sheathing will not be necessary using this product.
andy... cedar bureau sucks when it comes to giving advice..
IMMHO:
first.. they don't show a drip edge.. use copper on the eaves and the rakes
2d if you change your roof to skip sheath, you also change the racking strength of the roof plane... mebbe good ..mebbe bad..
the cedar breather will give the same results with less labor.. and you can still use ice & water at the eaves..
you definitely live in a humid area.. and mostly this is a function of drying times... wood shingles on a roof get wet.. they get wet all the way thru.. and then they stay wet on the bottom.. leading to premature failure... coastal ny and new england is definitely in this danger zone.. so either skip sheath or cedar breather..
the cedar bureau should spell this out but they don't .. lots of roofs have been installed with felt right over plywood as a result.. and it should never have been done or recommended...
with copper drip edge it is a lot easier to detail your roof and hide either the skip sheathing or the cedar breather.. you will also not have as much capillary action on the eaves or the rakes as the drip will divert some of the water returning by forming a partial capillary break...
we used thick butts , cedar breather, copper drip edge, ice & water, and a cedar ridge board ( vented ) on a 1670 cape .. worked great....Mike Smith Rhode Island : Design / Build / Repair / Restore
Mike
Just as I always thought.
I did a museum roof last year (a house a bit younger than mine in a state park up the road from me).
I used ply then stuck on water and ice shield on the entire roof.
It was an addition to the old house I was roofing so the cost wasn't much of a factor and the pitch was real shallow so....I then used Cedar breather. Very expensive stuff by the way.
My inclination has always been to use 30# felt which I already installed with W&I.Shield on the eaves.
The copper drip edges sound right. Thanks on that.
I always wondered how to vent the CB though, because it won't happen on the gable ends being that I'll be installing crown there covering it all.
I wondered how the ridge gets done.
Seemed to me it should be done the same way I do a normal (lol) roof using the mesh ridge vent and cedar on top.
I see so many houses going up now with the cedar right on the deck and I'll betcha a case O beer the shingles arent treated.
Thanks again Mike
and be well to you and yours
andy"My life is my practice"
more pic"My life is my practice"
frontal"My life is my practice"
I love strippers: )
"My life is my practice"
Edited 3/19/2004 12:30 pm ET by ANDY CLIFFORD(andybuildz)
Andy, I think the diagram you are referencing shows SHAKES being installed over interleaved a tar paper. Shingles are a different matter....I assume you're doing shingles, or maybe I missed something.
I agree that our area (i'm across the sound) IS humid, and I'm a big chicken. I would ventilate somehow.Jake Gulick
[email protected]
CarriageHouse Design
Black Rock, CT
>> ... shows SHAKES being installed over interleaved a tar paper. Shingles are a different matter.
Is that because the rough surface of the shakes already provides some ventilation?
Thats the way I understand it.
I've nver installed any shakes, but i've done Cedar....15 years ago, last check it still looked good. (They should cut back one tree though). That was over skip sheathing.Jake Gulick
[email protected]
CarriageHouse Design
Black Rock, CT
JAke (and the family jewels.lol)
I'm gonna bite the bullet and just use cedarbreather like I have in the past.
I spose my question was because of seeing so many houses with nada under the cedar.
Far as treated perfections go.yeh right!
For the area I'm going to cover which is probably a bit more than half the entire house its going to cost me about $1200 + tax.
Thing is.....I don't even believe CB is all that effiecient but its better than nothing,
Cost actually "does" matter to me cause its my house I'm doing this on.
Not a gig I can pass the #on to.
The 1x idea is great but tween time and material it'd probably end up being more $.
Wish I could use lathe vertically and horizontally but......well you know.
I'm sure I'll end up with CB......but be sure I'm gonna check out Ebay.....lol
Thanks guyz and
BE venting
andy"My life is my practice"
Andy- They often apply cedar shingles right over felt on plywood here in KY. Then they do it again in about 10-12 years. I've replaced several cedar roofs that were less than 10 years old and severely rotted. My answer has always been to use furring strips over plywood and felt (and or IB) and detailing the edges as Mike suggested. I use 4'-5' lenghts of furring and leave a couple of inches between the butts with a random stagger to allow air to work up from the bottom. The first roof I did like this is about 20 years old and should last another 10. I looked at it this week (some ridge caps blew off in a wind storm). Benjamin Obdyke makes a ridge vent for cedar. I've also used Cobra vent and cut the width down to be more in scale.
Where in KY are you?
We have Sphere in the Lexington/Richmond area and me just outside of Louisville.
Gotta be carefull getten all bunched up in one state , like them guys on the east coast.
dave
Where outside of Louisville? I grew up in Shelbyville - been in Lexington for last 30 yrs. Sphere and I've hooked up. Gonna go check out his cabin in the next week or so. Got a job down his way.
About 5 mi. outside of LaGrange, near Smithfield. I can be in Shelbyville in 25 min.
Drop me an e-mail next time you are near, and maybe we can hook up for a coffee somewhere.
Dave
Sounds good.
Andy,
I'm with greecu on this one. I've done it that way, spec'd by the owner by the way, and have had excellent reults. Southern NY.
Good luck, you got your work cut out for you. And here's wishing for good weather for ya!!
Eric
<<Good luck, you got your work cut out for you. And here's wishing for good weather for ya!!>>
eric,
Thanks bro and I think the weather will come in with perfect timing.
All the framing is finished and now I'm trying to finish up the existing living room which also is almost done. One more week I think which is the time it takes to get my cedar order delievered.
Yep. Going with the Cedarbreather at $1200.whewww. Just more grist for the mill.
Be well and happy first day of spring
andy"My life is my practice"