On Thu, 14 Jul 2005 22:33:51 -0400, "Steve Lortie"
wrote:

One answer I keep hearing to questions on how to do things is to follow the
manufacturer's instructions.This manufacturer is specific about how to
install it of course. Sanding the fibergass would probably be easier than
laying new plywood for sure.

link to product site - http://www.ducan.com/products/dek_master.html

My concern is whether the plywood will rot being sandwiched between two
waterproof but airtight layers.

My concern
wrote in message
.. .
On Thu, 14 Jul 2005 20:42:31 -0400, "Steve Lortie"
wrote:

I have a houseboat and I want to redo the surface of the upper deck with
a
vinyl membrane like product. It requires a fresh clean wood surface to
glue
it to.
My question - can I nail/screw down plywood on top of the existing
surface
which is fiberglass over plywood? With the glass underneath and the vinyl
over it, will the plywood survive this or will it rot out quickly?

Thanks.

I would coat the plywood with Epoxy resin if I didn't want it to rot
out, especially the edges. Also make sure to use either marine or ext
plywood to prevent delamination.

But why not rough the fiberglass surface and glue direct to the
existing deck instead? You may have to use a different adhesive
product, but it seems a better option


Weebles Wobble
(but they don't fall down)

In reading the site, under the FAQs, they address application over
fiberglass:

http://www.ducan.com/products/dek_master_FAQ.html#02

Can I install the Dek-Master system over fibreglass?

Yes, sand the fibreglass with 50 grit sandpaper, this will rough up
the fibreglass to allow for better adhesion. Fibreglass is a very
rigid material and the wood sub-structure is constantly moving because
of temperature, and moisture content in the air, cracks in the
fibreglass may develop. These cracks must be v-grooved out using a
razor knife or something similar, caulk this gap by using ducan Rubber
fill-It or Ducan Duca-Flex caulking compounds.

Sometimes the fibreglass may have lifted away from the plywood
sub-surface causing a large bubble in the finished surface. The bubble
should be cut out and new fibreglass applied in this area and then the
Dek-Master vinyl can be installed.


NOTE: Ducan does not warranty the sub-surface to which the vinyl has
been applied, if the substrate is the cause of the failure, your
warranty will be null & void. Ducan always recommends a new plywood
sub-surface prior to installing the vinyl.

I think this is a much better idea than laying down a layer of
plywood.


Weebles Wobble
(but they don't fall down)