Wavy roof! Need opinions/advice

Roofmaster417 · 01-29-2012, 09:54 PM

That is HORRIBLE!!!!!!!!!!!!!!!!.,.,I don't know where to start.First off I would have NEVER installed a roof over that garbage.

!!!!!!!!!.,.,Wait.,., Was this something that progressed or was it like this afterwards?

stickner · 01-29-2012, 10:11 PM

Quote:

Originally Posted by Roofmaster417

That is HORRIBLE!!!!!!!!!!!!!!!!.,.,I don't know where to start.First off I would have NEVER installed a roof over that garbage.

!!!!!!!!!.,.,Wait.,., Was this something that progressed or was it like this afterwards?

This is a new build... The house is only months old. It has been this way for quite some time.

The more I read and learn (thanks to everyone here!), the more I realize this is probably an edge-swelling issue with the OSB. I learned that what my pictures are showing is called "telegraphing".

There could be a few reasons the edges swelled (assuming that is what it is). The first possibility, and the one I am hoping for, is that OSB boards were exposed to moisture before or right after installation.

The second possibility is that there is a moisture problem in the attic. Definitely a bigger issue and one I am hoping is not the problem.

So how would I know what is truly causing the edges of the OSB to swell (assuming that is what it is)?

Found this great article:
http://osbguide.tecotested.com/pdfs/shingleridging.pdf

Roofmaster417 · 01-29-2012, 11:59 PM

Could you post some pix of your truss to plate bracing preferrably the rafter tails.?.,Unless the O.S.B has been subjected to extreme amounts of direct moisture/constant while they were banded or on site then I have mixed feelings about them being the sole issue.

The plywood institute recommends O.S.B to see some moisture prior to installation and in some cases after.

loneframer · 01-30-2012, 06:31 AM

I'd start researching the sheathing product to see if there have been other complaints about it.

I'm basing my opinion on nearly 30 years in construction, of which nearly 20 was primarily framing.

You will have some variation in material dimension and also lumber crowns. Some unevenness is to be expected, although anything more than slight should not.

Lumber is also subject to changes in dimension and crown during the first 12 months or so due to the stabilization of moisture in the material. The framer can't be held responsible for something he has no control over.

Over the years, I've seen quite a few new products introduced to the market that didn't hold up to their product claims. I'd like to see some pictures of the building with no shingles over the sheathing, from either inside or out.

I still find nothing about those framing pics to be suspect. Every aspect looks very clean.

I'm 100% certain that it's sheathing related, either due to installation or product failure.

If I had to venture a guess, I think it's a spacing issue that may have been amplified by wetting of the roof deck before shingle installation. It's also possible that the bundled sheets were exposed to high levels of moisture before installation.

If the edges were swelled before installation, this condition was easily avoidable.

stickner · 01-30-2012, 06:38 AM

Quote:

Originally Posted by loneframer

I'd start researching the sheathing product to see if there have been other complaints about it.

I'm basing my opinion on nearly 30 years in construction, of which nearly 20 was primarily framing.

You will have some variation in material dimension and also lumber crowns. Some unevenness is to be expected, although anything more than slight should not.

Lumber is also subject to changes in dimension and crown during the first 12 months or so due to the stabilization of moisture in the material. The framer can't be held responsible for something he has no control over.

Over the years, I've seen quite a few new products introduced to the market that didn't hold up to their product claims. I'd like to see some pictures of the building with no shingles over the sheathing, from either inside or out.

I still find nothing about those framing pics to be suspect. Every aspect looks very clean.

I'm 100% certain that it's sheathing related, either due to installation or product failure.

If I had to venture a guess, I think it's a spacing issue that may have been amplified by wetting of the roof deck before shingle installation. It's also possible that the bundled sheets were exposed to high levels of moisture before installation.

If the edges were swelled before installation, this condition was easily avoidable.

As an FYI, 90% (or more) of the homes in our section of the sub division have the same problem.

tinner666 · 01-30-2012, 07:22 AM

Quote:

Originally Posted by stickner

As an FYI, 90% (or more) of the homes in our section of the sub division have the same problem.

And just keep on cranking them out, eh? Sheeeeesh!

Roofmaster417 · 01-30-2012, 08:46 AM

If that was my house this is what I would do.Since all the homes in your immediate area contain the same problem and for some reason nobody is really concerned (besides you).And for the fact they are still building without regard.

I would contact the nearest University that has an architecture major/engineering etc..If you invite about 60 up and coming architects/engineers to your neighborhood as an extra curricular activity as a source of future structural concerns I think they would jump on the opportunity to find the culprit..

I am confused as to why they are still building.We are having about 10-15 homes going up everyday but nothing looks like what is being built in your subdivision.

jmiller · 01-30-2012, 10:09 AM

Quote:

Originally Posted by Roofmaster417

I would contact the nearest University that has an architecture major/engineering etc..If you invite about 60 up and coming architects/engineers to your neighborhood as an extra curricular activity as a source of future structural concerns I think they would jump on the opportunity to find the culprit..

That is not a structural problem. Standard OSB gets installed tight all too often, but generally doesn't look that bad.

My guess is that sheathing was allowed to get wet before the roof was installed, and after it was installed there was no way for it to dry inwards toward the attic because there is a radiant barrier on the underside acting as a vapor barrier. Depending on the underlayment used, the moisture could have been completely trapped.

Roofmaster417 · 01-30-2012, 10:18 AM

It is recommended for O.S.B to get wet before installation.But how wet the decking was is the question.Maybe a call to the plywood distributor and manufacture is needed.

I have roofed new construction that has been in the weather 2 or 3 weeks before it was roofed.I have seen nothing like that.

titanoman · 01-30-2012, 04:46 PM

Quote:

Originally Posted by gopher59

Normal construction is 1/2" to 5/8" sheeting over 16" center rafters. At least 3/4" sheeting over 2' center rafters. You definitely have a framing problem and the roofers should never have put the roof on this. This goes back to the general contractor and his framers and is his responsibility. Hold all funds immediately!

5/8" is prefered for 2' o/c, even though 7/16" osb is real common.
You don't need to go 3/4" just because the rafters are 2' o/c.

MJW · 01-30-2012, 04:50 PM

I think jmiller is right and kinda what I was getting to also.

As for OSB, most of it here is 1/2" on 24 inch centers with clips. None look like that. I have done a house that the OSB was rained on for 2 months while the framer was out of town. It swelled up to over an inch thick. The homeowner acting as the GC said "roof it, I don't care. It needs to be covered up". We roofed it. This was 5 years ago now and there still isn't any problems and it doesn't show any effects like these pics.

titanoman · 01-30-2012, 05:00 PM

Quote:

Originally Posted by gopher59

Oh well, here we go again mjw, funny how I never hired you to do my roof. You cannot use 1/2" or even 5/8" sheeting unless you are at least 16"oc (guess I have to explain to you what oc means, that means each rafter is 1-1/2" and from center of one rafter (3/4") to the next is 16") If you are 2' oc, you need at least 3/4. Go fly a kite somewhere and quit getting on here and acting like you are a roofer when it is obvious to everyone here you are fos.

Apparently you are a newbie in the construction world. I don't think anybody here is going to agree with you.
Have you ever heard of plywood clips? Do you know what they are for? School me, would you.
Oh. And o/c stands for the Officer of the Order of Canada, doesn't it? Isn't that what you're talking about?

loneframer · 01-30-2012, 05:27 PM

Quote:

Originally Posted by gopher59

Oh well, here we go again mjw, funny how I never hired you to do my roof. You cannot use 1/2" or even 5/8" sheeting unless you are at least 16"oc (guess I have to explain to you what oc means, that means each rafter is 1-1/2" and from center of one rafter (3/4") to the next is 16") If you are 2' oc, you need at least 3/4. Go fly a kite somewhere and quit getting on here and acting like you are a roofer when it is obvious to everyone here you are fos.

I've been building new homes since 1985 and have seen hundreds of trussed roofs on 2' centers with 7/16" OSB or 1/2" plywood and clips. I know exactly what OC means and back MJWs statements completely.

Jmiller brings up a good point with the foil face on the sheathing product. That is suspect to me as well.

titanoman · 01-30-2012, 05:54 PM

Sorry, gopher. You addressed mjw earlier and I thought you were talking to me.
My real bad.

MJW · 01-30-2012, 06:11 PM

It really doesn't matter what you say gopher. It is what it is. I have plenty of experience and not going to get into a pissing match with you. I really don't care how much experience you have or don't have. I don't want to rip on you personally, but what I said is true and what you said is false. That's it.