roof tear-off project gut check

[Ed Lim]

We are in the process of having our roofed replaced and would like to get feedback on whether it is just right, an overkill or a dumb choice..

We live in Portland Oregon and have a 20 acre forest right in our backyard. The house was built in 1987 w/ original shingle roof shake. It had a leak last month and we knew it was time to bail out. The roof pitch is 3/12 and the house is split level with cathedral ceiling in the living space area.

We have asked for 3 quotes but got 5, price range bet. 9,000 and

12,000.

3 of the contractors said the shake was bad news for that type of roof but it was very popular during those days.

we were going with the certainteed tl lifetime but again 3 would not recommend that type bec. of the slope. the most recommended roof was the certainteed landmark 30 - 50 series.

So this is what we came up with:

complete tear off certainteed landmark 30 or 50 shingle grace ice and water shield on the entire roof

1/2" cdx plywood on top of the existing slats install new flushings, air vents, hip and ridge material, etc....

the contractors were selected from certainted's web site of certified installers. i threw home depot in the loop just to see what they could come up with but i was not impressed with the presentation. but that is another story...

we chose the ice and water shield over felt bec. we thought it will add more protection.

any comments and feedbacks would be most appreciated. we would like to start work mid-february.

thanks.

[charlie]

in article [e-mail], Ed Lim at [e-mail] wrote on 1/28/04 5:45 PM:

i am no expert, but make sure the sheathing is checked where the leak was. that is why most recommend a tear off, so you can check your deck before putting the shingles on. just had mine done and i had to replace a section around a vent. didn't notice any leak.

[Tom]

Howdy. 3 in 12 is a very low pitch for either cedar shingles (thin, smooth) or cedar shakes (thick, rough). Which kind of cedar roofing material is it? Portland Oregon's kinda wet, too, isn't it? The leak you had last month, did it coincide with a freezing spell? Was it near an overhang, or behind an appurtenance? Tom Someday, it'll all be over....

[Duke]

Comments inserted

If you had a company that specialized in shakes come out, your probably wouldn't have gotten the same response.

Certainteed also offers 40 yr. Landmark. A note on the Landmark in case none of the companies told you, the now 30 yr. Landmark used to be rated 25 yr., the now 40 yr. Landmark used to be rated 30 yr. , and the now 50 yr. used to be rated 40 yr. Certainteed didn't change the shingle, but through testing upped the rating. I got this information through Certainteed's newsletter about 3 yrs. ago.

If available in your area, and since you're by woods (don't know if your home is shaded or problem with algae), you may want to look into the Landmark AR series (algae resistant). Also don't discount the 40 yr Landmark which is a pretty darn good shingle.

Why Grace and not Certainteed's water & iceguard? I heard but can't confirm Grace is warrantied for 15 yrs, doesn't make much sense to use it with a shingle over 15 yr. (Maybe someone will chime in and correct on what I've heard) Certainteed water & iceguard is warrantied for the life of their shingle, whichever year you use, this was also in their newsletter.

As already mentioned about a lesser cdx such as 3/8", if sold on 1/2" cdx you want specification on if a 3 ply or 4 ply. Alternative to cdx _could_ possibly be 7/16" OSB.

Make sure the appropriate matching accessory cap is used, some cheap out on the job and use a 3 tab shingle close in color, but this is not the correct cap for Landmark. Is noticeable especially if you have a hip roof. I'm also a firm believer in cap over ridge vent by AirVent Corp., which Certainteed owns.

I wouldn't put much stock in Certainteed contractor website, not to down talk it, but to get on there you pass a couple of open book tests. You still want to talk to past customers about the companies work habits, any pitfalls and how the contractor handled it. Just a side note, I know about the tests because I happen to be on their website also.

For iceguard to properly seal, temperatures must be above 40 F. If at all possible, I would get a temporary patching and wait until spring.

[John Willis]

On Thu, 29 Jan 2004 02:43:44 GMT, "Duke" scribbled this interesting note:

Unless a customer specifically desires OSB, we never use it. Despite the propaganda put out by the manufacturers, it does not hold nails as well and it hasn't nearly the strength of plywood.

BTW, so far as I know, all plywood products have odd numbers of layers, never even. This makes the plywood very strong in one direction, although weaker in the other. Even though 3/8" plywood is sufficient by FHA standards, it is far from sufficient for any real roofing application. If you've worked on many houses decked with 3/8" plywood you'll know exactly what I mean.

-- John Willis (Remove the Primes before e-mailing me)

[Duke]

I'm not going into this debate, it's been beat to death if you follow the NGs, especially on the strength issue. You will note this is going over a substrate (slats) already down (I believe you missed that part). For nail holding power, I suggest you use a barbed coil nail since you have problems.

I was speaking of 1/2" CDX, here you can buy 3 ply or 4 ply, evidently it's not offered in your area, so now you know there is such an animal. I worked on houses with 3/8", 24" O.C., we are not allowed to cover this with roof material once found out. We _must_ put at least 7/16" over it, our codes are not as lax as they once were. 3/8" is not sufficient by our local codes, one code they should change everywhere.

[Tom Baker]

Ed, Based on what you present, that's a good roof. If it were mine - given the low slope and near by trees - I'd consider a metal roof. There are a lot of metal roof materials and assembly systems, and an experienced installer is most important. In return one gets a roof with long life, no moss, no leaf build up, and little or no maintenance. Tom Baker Charleston SC

[Joe Bobst]

A wise choice IMO. In our area (midwest) metal roofing, usually standing seam, is finding its way into many upscale homes. Fifty year warranties are the norm. But bulders tend to use materials from local sources, hence cedar shakes in Oregon. All things considered, if it doesn't clash with neighborhood structures, I'd go the metal roofing route. HTH

Joe

[Duke]

"Tom Baker" wrote

Excellent option and advice TB

[John Willis]

On Thu, 29 Jan 2004 04:21:36 GMT, "Duke" scribbled this interesting note:

"...Plywood is made from thin sheets of veneer that are cross-laminated and glued together with a hot-press. Imagine the raw log as a pencil being sharpened in a big pencil sharpener. The wood veneer is literally peeled from the log as it is spun. Resulting veneers have pure tangential grain orientation, since the slicing follows the growth rings of the log. Throughout the thickness of the panel, the grain of each layer is positioned in a perpendicular direction to the adjacent layer. There is always an odd number of layers in plywood panels so that the panel is balanced around its central axis. This strategy makes plywood stable and less likely to shrink, swell, cup or warp."

This is Copyright 2002 University of Massachusetts, Amherst. Found it on their website.

Hope this helps.

-- John Willis (Remove the Primes before e-mailing me)

[Ed Lim]

the roofing metrial is cedar shakes. i also noticed that the shakes in the steeper part of the roof were in much better shape than those in the low slope area. we already had a leak last year on the same spot, paid a guy to "fix" the problem. he came back 4x and then it stopped raining. i phoned him this year and he never showed up.

we do not have trees right above the roof and alage/moss is not a major problem. the forest is behind the propery line, about 30 feet away from the roofline.

we are also thinking about adding blown-in insulation while the roof is off. and adding a ceiling fan since we can run wires at the top.

[Duke]

Like I said, now you know there is such an animal, pick your choice to read.

[PJx]

You're a fool unless you go with a metal roof. I like red. PJ

[John Willis]

On Thu, 29 Jan 2004 16:41:09 GMT, "Duke" scribbled this interesting note:

Live and learn...thanks for the update.

-- John Willis (Remove the Primes before e-mailing me)

[Bob]

like to

our

shake.

I would think a cedar roof, properly maintained, should last a lot longer than that. Are you sure it can't be repaired?

If you get it torn off, there will be a huge mess in the attic space below it. If you want to avoid having a horribly dirty attic, spread plastic over the insulation before the teardown, and clean it up after.

Bob

[Ed Lim]

well, in the area where we live, most houses still have the cedar shake roof so having a metal roof will make us look "different". i think we will stay with the certainteed 50 year roof.

[Duke]

Your welcome. I have used the 4 ply cdx for at least 15 yrs, I would imagine it's been out longer than that. Once you use 4 ply 1/2", you will never go back to the 3 ply. Here it's about $3.50 a sheet more than the 3 ply.

[Phil Scott]

I am not a roofing expert. In this area fire proof roofing is highly recommended, you are near a forest. Have you looked at metal roofing?

Phil Scott

[3D Peruna]

Ed...

If it's low slope, I'd go with metal. But, if you do decide to go with ashpalt shingles, be sure that the warranty applies if they're installed in a low-slope condition. Sometimes, there are clauses that limit or change the conditions.

P

[David J Bockman]

Many people have already responded, but I'll add my $0.02...

No doubt your shakes were installed incorrectly, as were 99% of shake roof construction in the 80's-- without sleepers behind them or at least a thick air infiltration membrane behind. Properly done, a cedar shake roof should last at *least* 30 years, if not double that.

Dave