Roof Issue Lesson

[Peter C. Russell]

PS the clips are designed to stabilize the roof sheathing in between the bays not for expansion and contraction.

[Ed Fako]

The only one who I have seen on here that has an extremely rounded and thorough understanding of roofing issues on a consistent basis, is Marcel.

I know what this is, and so far everyone is incorrect regarding H-Clips.

Certainteed and the APA have a document regarding this.

Ed

[Kenton H. Shepard, CMI]

Erby, is the answer going to take us back to the "V" disagreement? Because there are no voles, viceroys or vermiculite visible on that home.

[jkogel]

I'll take a stab - the decking was wet before the shingles were laid? Just by coincedence, I took a similar pic this AM, this on a townhouse. Different pattern though....

[Barry Adair]

Originally Posted by Ed Fako

The only one who I have seen on here that has an extremely rounded and thorough understanding of roofing issues on a consistent basis, is Marcel.

I know what this is, and so far everyone is incorrect regarding H-Clips.

Certainteed and the APA have a document regarding this.

Ed

Ed, that's a pretty broad brush you're painting with there ...................................just as long as my client's don't find out

[Erby Crofutt]

It's spacing. OSB expands and contracts based on humidity.

This just shows the edges bridging up where they've pushed together.

Get all the OSB facts at the Structural Board Association website.

Dowload the gjuide or brochure suitable for your area and usage.

http://www.osbguide.com/osbliterature.html

While H clips are not always required based on thickness and support spacing, they do help maintain space between sheathing.

Goes back to "minimum standards" (i.e. building code) versus "best practices".

[Marcel R. Cyr]

This may help explain somewhat;

http://www.osbguide.com/pdfs/ShingleRidging.pdf

http://www.buildingscienceconsulting...ented_roof.pdf

Marcel

[cyezza]

Originally Posted by ecrofutt

It's spacing. OSB expands and contracts based on humidity.

This just shows the edges bridging up where they've pushed together.

Get all the OSB facts at the Structural Board Association website.

Dowload the gjuide or brochure suitable for your area and usage.

http://www.osbguide.com/osbliterature.html

While H clips are not always required based on thickness and support spacing, they do help maintain space between sheathing.

Goes back to "minimum standards" (i.e. building code) versus "best practices".

I would always use H-clips on trusses 24" oc

[Marcel R. Cyr]

More on h-clips and sheathing spans.

Seems like Code compliance and standard building practice don't match. ha. ha.

Imagine having a 3/8" roofing underlayment at 24" spacing. Hey its ok by code.

http://www.tecotested.com/documents/...Tip_HClips.pdf

Marcel

[Marcel R. Cyr]

Here we go, let's eliminate the h-clips and felt paper alltogether.

http://www.huberwood.com/media/pdf/Z...esBenefits.pdf

Marcel

[Ed Fako]

Originally Posted by badair

Ed, that's a pretty broad brush you're painting with there ...................................just as long as my client's don't find out

Sorry Barry,

That remark was in no way intended to diminish my appreciation for the knowledge and fact finding capabilities of many many other posters. It was more of an affirmation about Marcels working background, which seems to have a deep root in roofing techniques.

If I came off the wrong way, I will personally write your customer testimonial letters for you.

That other, more recent photo posted, looks like deeply sumped decking deflection, by the way.

Ed

[jkogel]

Originally Posted by Ed Fako

That other, more recent photo posted, looks like deeply sumped decking deflection, by the way.

Ed

Would this be simply using way too thin OSB? Combined perhaps with a ventilation deficiency?

[Kenton H. Shepard, CMI]

No ventilation at all in roof or gable. Ridging looks uniform accross the roof so is the source of the moisture the home interior?

[Mathew Hawley]

Were the pictures taken in late evening? Many times raised sections stand out more depending how the sun is angled on the roof.

[Ed Fako]

Originally Posted by jkogel

Would this be simply using way too thin OSB? Combined perhaps with a ventilation deficiency?

Well, without being able to count the shingle tabs for width, it looks like 24" O.C. rafters.

My guess from seeing similar roofs is the rafter spacing is too wide in addition to the decking thickness being either a cheap 3-ply cdx or a 3/8" cdx.

The improper ventilation just compounded the deflection by steaming away the glues that bond the plies together.

Ed