Community Forums

rodekyll · 09-10-2019, 10:35 AM

I am planning to replace the forward sub-floor in my 2001 Newmar MA DP. There is an old but continuing leak that I suspect is coming from the driver side window seal. I need to fix that first (just found it last night and need to evaluate), but as soon as I'm watertight I want to remove the damaged flooring around the driver seat, N/S from the front of the slide to the front cap, and E/W to about the centerline. I want to replace the rotted subfloor with something good. My intent is to finish with pergo (or equiv) wood. My go-to underlayment would be marine plywood. Can someone tell me why the would not be a good idea, and is there something better that is usually used here?

Dav L · 09-10-2019, 11:50 AM

Not sure if you have a roll down drivers window, but on mine there is a plastic rectangular box at the base (sits on the floor) that catches any water that gets passed the seals. There is a drain tub on the bottom of that box that brings the water under the RV. That plastic box had a crack and leaked out that water before it got to the drain tube and wet the carpet.

Possibly that's the source of your leak.

Rkesselus · 09-10-2019, 12:41 PM

I would look into treated plywood vs marine. Google one vs the other and make a decision so it is just not my recommendation. You will find that both have exterior rated glue the marine has more plys but is not treated for resistance to dry rot, pests and other elements destructive to the wood.

rodekyll · 09-10-2019, 12:55 PM

Maybe this part should be a separate topic. Thanks for the pointer. Yes, there is a power window. I do not see the tray. I'll pull the interior liner and look more closely. I have to get that driver seat out, too.

The lower window seal is hopelessly perished -- pulled away and spongy/cracked. When I cleaned it up and put the water hose to it, water flowed inside, freely.

Where can I find another seal?

rodekyll · 09-10-2019, 12:57 PM

Quote:

Originally Posted by Rkesselus

I would look into treated plywood vs marine. Google one vs the other and make a decision so it is just not my recommendation. You will find that both have exterior rated glue the marine has more plys but is not treated for resistance to dry rot, pests and other elements destructive to the wood.

I will look into that. Does "treated" imply that I can lay it down without prep?

rodekyll · 09-14-2019, 08:22 PM

Thanks for pointing me toward the drip tray. The drain was plugged. I blew it out and the water drained. Too bad it wasn't cleared years ago, before the overflow rotted the floor.

Dav L · 09-15-2019, 08:45 AM

Plug up the drain, put water in the tray and ensure that the tray doesn't have any cracks / leaks especially in the corners. StuartW did a nice write up on how he replaced it with a custom made stainless steel tray. I used silicone to fix the one corner on mine that was leaking.

BCam · 09-15-2019, 09:07 AM

1. "Treated" plywood could be problematical health-wise, depending on the chemicals involved, so be extremely careful. I don't think that standard exterior grade plywood would be an issue. Marine plywood is probably overkill but, if it's in your budget, go for it.

2. Pergo and other laminates aren't waterproof. Even the so-called waterproof laminates aren't good for more than 24 hours of exposure. Another leak like your current one can be problematical. Luxury vinyl planks, which install the same way as laminate, are a better bet. Chances are that the "wood" floors in your favorite restaurant are luxury vinyl, albeit the glue-down variety which is more common in commercial applications.

Dav L · 09-15-2019, 09:27 AM

re: plywood - if you fix the leak (the drain), then just put in what was in it.
If it's dry, any ply will work. Pressure treat chemicals have changed over the years so the concern is less today than it used to be. It will also be covered from direct exposure by your floor covering.

I don't see any reason to upgrade to marine ply since it will always be dry. Unless you have a piece kicking around that needs a new home and it's the right dimensions. Wood prices will likely raise again with all the hurricane damage going around.

bldrbob · 09-15-2019, 10:48 AM

The big difference in marine plywood is that the inner plys are solid with no voids.Regular plywood can have spaces in the inner layers that would allow water to travel between plys.Not good in a marine setting.

rodekyll · 09-16-2019, 02:32 PM

All good arguments. My reading leads me to conclude that the price points will make the final determination. Marine ply will be my plan A, because I'm more worried about moisture than bugs, and marine already has a nice finish on both sides. Treated will be plan B, and the original-type chop-and-resin plan C. Depending on how far inboard the damage goes and how I lay it I might get by with one full sheet. If I pull the entire damaged panels, it will take one full sheet and change.

Good notes on the flooring choices, too. There's some sort of "pergo" style flooring in the galley area already. It appears to be glued to the subfloor. I can see where the surface at the edges is slightly warped due to water intrusion. I hate to pull that 100 or so sqft, but in the interest of form over function (I'm not usually "that guy", but the interior designer in me outshouts the engineer) I might do the entire 310' for uniformity and overall project skookumness.

I'm heading for the flooring shop today to chat up the experts there and see what's in the overstock bin . . .

HJLowell · 09-16-2019, 03:06 PM

Most 3/4 flooring and roofs in the houseboat industry use 7 layer fir with one side finished.

Its easy to carpet, tile or fiberglass decks and roof.

They use it to make shelves and cabnets also.

The last I bought at 84 lumber was $48.00
A sheet.

No porus areas between layers.

gmc70 · 09-16-2019, 03:22 PM

Look into a product called Exteria. It is rot proof, termite proof, lays very flat, does not warp. It looks a lot like MDF but is an entirely different product. Down here on the Gulf coast we use it in a lot of exterior applications. If I had to redo a sub floor it is what I would use.

RKins · 09-16-2019, 03:30 PM

Quote:

Originally Posted by rodekyll

Maybe this part should be a separate topic. Thanks for the pointer. Yes, there is a power window. I do not see the tray. I'll pull the interior liner and look more closely. I have to get that driver seat out, too.

The lower window seal is hopelessly perished -- pulled away and spongy/cracked. When I cleaned it up and put the water hose to it, water flowed inside, freely.

Where can I find another seal?

Newmar told me they keep parts in stock for 20 years. Since they built that window (or installed it) they should have parts. Email CS and tell them the last 7 of the VIN, what you need, give them a couple days and they'll respond.