Reroofing with Clay & Concrete Tiles

[jeremy]

In the clay & concrete tile installation manual (ICC ES ESR-2015; http://www.monierlifetile.com/technicaltools/pdf/TRI-ModerateClimate-InstallationManual0806.pdf), on page 8 regarding reroofs it states that when reroofing a wood shake/shingle roof with clay or concrete tiles, solid decking is required in accordance with new construction.

I'm a little confused by this because both solid and spaced sheathing is allowed for concrete/clay tiles and for wood shakes/shingles in the 2006 IRC & IBC. Why would it say that solid decking is required when replacing only wood shakes/shinges? Why wouldn't it be required when replacing other types of roofing materials? And why would it be required at all when spaced sheathing is allowed by code?

 

[Mule]

Re: Reroofing with Clay & Concrete Tiles

Jeremy, I think it goes back to the installation of this specific roof. If you read on page 7...

Battens installed on roof slopes of 4:12 to 24:12 shall be

fastened to the deck at no greater than 24 inches on center,

and shall have provisions for drainage by providing ½-

inch separation at the batten ends every 4 feet, or by shimming

with a minimum 1/4" material of wood lath strips, 2-

inch shims, cut from multiple layers of material, placed

between the battens and deck to provide drainage beneath

the battens or other methods approved by the local building

official. Tile installed without projecting anchor lugs

may be installed as provided above as an optional method

of installation.

Isn't this saying that this type of roof requires solid decking with a way for moisture to drain between the tile and deck? Or am I reading this wrong?

 

[jeremy]

Re: Reroofing with Clay & Concrete Tiles

Yes, I agree with you, Mule, on the drainage issue, but if you look on page 68 it covers underlayment for spaced sheathing decks. So it's possible to have a skip roof deck, underlayment, and still have spacing for drainage between the battens.

 

[peach]

Re: Reroofing with Clay & Concrete Tiles

maybe because the solid sheathing needed to be there with the asphalt and/or wood shingles.

 

[Paul Sweet]

Re: Reroofing with Clay & Concrete Tiles

A lot of manufacturers have installation requirements that exceed code. If you don't follow them, the manufacturer can deny coverage for warranty or leakage claims. The installation instructions and warranty are both written for the manufacturer's protection.