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Re: Plywood Forms for Roof Sheathing?

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I agree with Paul. Don't make acceptance of reused panels "approved"
unconditionally. There are lots of things that can happen to the plywood (or
OSB?) during forming, such as roughening of the surface especially if not
cleaned of concrete particles, buckling or warping of the panels, delamination
(heaven forbid), holes for form ties, odors from form release agents (if used)
that could make the surface slippery if wet from dew or rain, etc. Surface
roughness or uneveness due to adhered blobs of concrete might telegraph through
roofing, such as shingles or built-up roofing.  Notwithstanding these potential
problems, the building or homeowner may object to reusing "used" panels,
especially in view of the cost of construction.  The owner might reasonably
expect that new materials will be used for all sheathing.  The contractor would
like to reuse these panels if permitted, to save construction costs (and may
pocket the resulting cost saving without passing the savings on to the owner).
In the "old days" of nom. 3/4 in. board lumber sheathing, such sheathing was
often used for foundation forms, then reused for spaced or sometime solid deck
lumber roof sheathing. This practice is not followed much any more.  As a
minimum, I would suggest that approval be obtained by the contractor from the
building owner, and that reuse should be based on reinspection of the panels for
suitability after they have been used for forming. I wouldn't advise a "carte
blanche" approval of such practice.
John Rose (APA-retired)

Paul Crocker wrote:

> I don't think you want to take the liability if the owner/tenant starts
> complaining of the stench of form grease coming from their attic.  Forms can
> get pretty nasty if they've been used a few times.  If it is in good shape
> and they demonstrate it meets all applicable specs and you don't
> specifically object, that's one thing, but endorsing it seems quite another
> thing.
>
> Paul Crocker, P.E.
>
> -----Original Message-----
> From: Neil Moore [mailto:nmoore(--nospam--at)innercite.com]
> Sent: Tuesday, October 16, 2001 3:19 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Plywood Forms for Roof Sheathing?
>
> Have a contractor who wants to make a correction to my general notes
> drawing as follows:
>
> "OK to use Plywood from forms for Roof Sheathing Plywood".
>
> This is in an 80 mph, exposure C area, zone 3 on a 11,000 sf - one story
> building with heights up to 30 feet.
> Any comments?
>
> Neil Moore, S.E.
> neil moore and associates
>
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