4 x 9 plywood

[tim-n-tn]

I'm trying to re-roof my 94 gulfstream conquest that is 8'5" wide w/ 1/4" luaun. I've tried lowes and home depot and they do not offer 4 x 9 or 4 x 10 sheets. any suggestions on where to find this? My other option would be 4 x 8 sheets with a brace between the rafters to splice an 8' sheet to the 5" piece so that it is fully supported underneath. any suggestions will be appreciated! Thx, tim-n-tn

[burningman]

I don’t even need any plywood and I’m learning things reading all the discussion about it.
Even when we take little jabs at each other. (That’s pretty much how guys are in real life, so... )

[myredracer]

For plywood longer than standard 8', see if you have a local plywood specialty shop. We have one here that has pretty much every type of plywood you can imagine including 10' sheets (and 5' wide).

Can't tell for sure without seeing some photos or being there, but I would think you should be able to work with 8' long sheets. Heck, you *could* even make longer sheets of plywood by gluing overlapping sheets of 1/8" together.

[DrewE]

Horsedoc wrote:
Not just this thread, but many. Someone asks a simple question and then gets covered up with technical 'how to'.
Almost like asking for the time of day and gets instructions on how to build a clock.

The simple question was asked...and a couple very reasonable answers given. The poster also stated that any suggestions would be appreciated, and received several suggestions related to their query and ideas.

Discussion is rather par for the course in a discussion forum.

[Horsedoc]

Not just this thread, but many. Someone asks a simple question and then gets covered up with technical 'how to'.
Almost like asking for the time of day and gets instructions on how to build a clock.

[dougrainer]

Bill.Satellite wrote:
Rubber membranes can get holes.

Are you serious? DUMB response. Holes only happen when you HIT something. Marine Plywood is NOT going to stop water intrusion into the RV if you get a hole. Doug

[Cummins12V98]

drsteve wrote:
Marine plywood is hardwood plywood made with a waterproof adhesive. It is not waterproof or rot resistant.

Douglas Fir is a Soft Wood

Roseburg’s AB Marine Panel is marine-grade plywood that is produced entirely of Group 1 species of veneer. Our marine plywood panel is sanded on both faces. The maximum core-gap size permitted is 1/8 inch. Its exposure durability rating is EXTERIOR and the glue used is a water resistant structural adhesive. It is considered a premium grade panel for use in situations where these characteristics are required. Specialty sizes and thicknesses are available.

SPECIFICATIONS

Lengths: 8’, 10’
Widths: 4’
Thickness: 1/4’’, 3/8’’, 1/2’’, 5/8’’, 3/4’’, 1’’
Face: A grade Douglas-fir Veneer
Core: B grade or better Douglas-fir Veneer
Back: B grade Douglas-fir

I think you are referring to Hardwood Plywood

Hardwood Plywood

Hardwood Plywood MDF Veneer coreJ. Gibson McIlvain carries a full line of hardwood plywood in a variety of the most popular species:

Cherry
African Mahogany
Natural Birch
Natural Maple
Red Oak
Sapele
White Birch
White Maple
Walnut
White Oak

Hardwoods and Water do not mix, I know first hand of White Maple and water = BAD.

[drsteve]

Marine plywood is hardwood plywood made with a waterproof adhesive. It is not waterproof or rot resistant.

[Cummins12V98]

DrewE wrote:
Depending on what kind of a joint you make, splicing can be perfectly fine. A properly made scarf joint, for instance, will be as strong as the base plywood. Making one would require the construction of a jig or two of some sort, or using one that someone else has made.

A scarf joint is basically just a very shallow angle wedge or miter sort of joint, typically something around 1:8 or 1:10 rise to run. For 1/4" plywood, it should be possible to cut the angles with a Skilsaw and a suitable jig; though I'm speaking not from experience but only from thinking it through as I'll also be replacing my motorhome's roof this year.

UH, NO!

A simple end butt of the plywood with a solid 2X under the joint with construction adhesive and screws will work JUST FINE!!!

If you really want a continuous pc go to a Lumber Yard that caters to the Construction Professionals.

EXTERIOR grade is all you need. Marine is going to cost WAYYYY more for no good reason.

[Bill_Satellite]

Rubber membranes can get holes.

[dougrainer]

wa8yxm wrote:
I like the "Marine" suggestion too. and make sure it is MARINE grade as well. Stands up to weather better.

It is covered by a rubber membrane. WHY would it need to stand up to any weather???? Doug

[DrewE]

Depending on what kind of a joint you make, splicing can be perfectly fine. A properly made scarf joint, for instance, will be as strong as the base plywood. Making one would require the construction of a jig or two of some sort, or using one that someone else has made.

A scarf joint is basically just a very shallow angle wedge or miter sort of joint, typically something around 1:8 or 1:10 rise to run. For 1/4" plywood, it should be possible to cut the angles with a Skilsaw and a suitable jig; though I'm speaking not from experience but only from thinking it through as I'll also be replacing my motorhome's roof this year.

[wa8yxm]

I like the "Marine" suggestion too. and make sure it is MARINE grade as well. Stands up to weather better.

[dougrainer]

We get it from a large lumber supplier in the DFW Texas area. Retail cost(what we would charge over the counter and what Insurance pays us on roof jobs) for a 4 by 10 foot sheet is $56.68. Doug

[Chum_lee]

tim-n-tn wrote:
I'm trying to re-roof my 94 gulfstream conquest that is 8'5" wide w/ 1/4" luaun. I've tried lowes and home depot and they do not offer 4 x 9 or 4 x 10 sheets. any suggestions on where to find this? My other option would be 4 x 8 sheets with a brace between the rafters to splice an 8' sheet to the 5" piece so that it is fully supported underneath. any suggestions will be appreciated! Thx, tim-n-tn

You can find the right sized sheets (and proper fasteners) with a little searching. IMO, splicing shorter sheets together would be a VERY BAD idea. In fact, you should cut the replacement sheets (as necessary) as closely as you can to replace the existing sheets. IMO, any future soft spots in your roof are a bad idea.

Chum lee