Tips on bathroom Subfloor replacement

Floor Repair, Inner Skins, Furnishings, Interior Finishes
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Innocent.Smith
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Joined: Tue Aug 08, 2017 8:44 pm

Tips on bathroom Subfloor replacement

Post by Innocent.Smith »

I am wondering if anyone has tips for replacing a partially rotten subfloor in a bathroom? The area surrrounding the toilet is rotten and some places beneath the old tub are also questionable.

Also any recommendations on repair persons in the Nashville area? Not sure if this job is above my DIY grade.

Thanks!
silverloaf
Posts: 763
Joined: Wed Aug 23, 2017 9:01 pm

Re: Tips on bathroom Subfloor replacement

Post by silverloaf »

Hello Innocent,
I am in process of re-furbishing a 1988 30W. The bath is in the rear. I have holding tank issues that rotted out 2 steel sub-frame members supporting the tanks and bathroom floor. Fortunately, the plywood is above the damaged frame pieces.

If it were my trailer, I would carefully remove the bathroom components (or portions of it) to expose the damaged floor. It might be possible to section in new pieces of flooring. I would want to know the size of the elephant before commissioning repairs.

Bear in mind the lower exterior body skin is tucked under skin above it. This transition occurs at the floor line. A strip of belt line trim covers the seam.

This body skin intersection is riveted to the edge of the plywood floor. Any portion of the plywood floor damaged near its edge will require surgically separating the floor from the skin.

The rivets must be drilled out with heads knocked off. Some rivets are hidden by access door trim pieces that must be removed. It is a labor intensive process to avoid bending or bucking the skin.

The above would be your worst-case scenario. But I have confidence you can perform at least the diagnostic investigation. I can refer you to a Avion repair facility in west Michigan if you want a 2nd opinion.

Blessings.

Bob
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
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KYAvion
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Re: Tips on bathroom Subfloor replacement

Post by KYAvion »

When you removed the fasteners between the plywood floor and the trim for the exterior skin seam, how did you go about reattaching after the new floor is in? Or if a small area did you just let it go since I suspect those fasteners primarily serve to hold the exterior trim in place and do nothing structural?
KYAvion
1984 Avion 30R
silverloaf
Posts: 763
Joined: Wed Aug 23, 2017 9:01 pm

Re: Tips on bathroom Subfloor replacement

Post by silverloaf »

KY-

I trying to avoid replacing the floor across the width of the trailer. There is some decay at the bottom of the service doors in the left rear corner. I'm investigating some products that strengthen decayed wood. Here's one product. It's made by System 3 :
https://www.amazon.com/dp/B00UVH1PFG?psc=1

So far as the staples, I used a vibrating saw to cut the staples. I was rather strategic. I avoided any that required removing large sections of outer skin.

Bob
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
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KYAvion
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Re: Tips on bathroom Subfloor replacement

Post by KYAvion »

I had a lot of rotten wood in the same corner area, which I discovered when replacing the water heater. The wood literally fell apart during removal. Because this area is hidden and the water heater needed to sit up a little higher anyway, I just layered a new piece of plywood on top. As far as the fasteners through the outside edge banding l, I left them in place since the wood literally flaked apart. Having them embedded in the plywood didn't seem to do anything structurally, so I didn't worry about it.


topic47.html
KYAvion
1984 Avion 30R
silverloaf
Posts: 763
Joined: Wed Aug 23, 2017 9:01 pm

Re: Tips on bathroom Subfloor replacement

Post by silverloaf »

KY-

I have removed everything out of the rear bathroom. The wall unit is resting against one bed frame; the tub is sitting ln top of the other.

I too am considering a thin sheet of underlayment from wall to wall. Need a smooth base for new flooring. However, I'll to cut a slot for the wall unit. The unit won't go back into proper position if the floor surface is raised.

So far as removing staples, it wasn't my 1st choice. But there were many layers of aluminum around the water heater that hampered its
removal.

Bob
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
silverloaf
Posts: 763
Joined: Wed Aug 23, 2017 9:01 pm

Re: Tips on bathroom Subfloor replacement

Post by silverloaf »

I have completed replacing the floor assembly in the rear of our '88 30P. Our unit has a full bath in the back. Most of the floor had either rotted out or delaminated. It stunk up the entire trailer.

I installed some bracing between the top of the rear service door frame and the driveway. The body is a structural assembly and very rigid. The key is the spray foam; it adds tremendous strength to the aluminum skin and framing as a system. Supporting the side walls added little value.

It took me about 2-1/2 solid weeks to cut out the old floor, replace some rusted-out steel sub-frame (thanks to my son) and then craft a new structural floor. I did it in two sections. For the rear, I made a cardboard template in order to mimic the rounded corners. The shape of the corners is actually an ellipse, not a radius.

I transferred the template to the plywood, and built the floor assembly on a work table. When installed, it fit like a kid's glove under the outside walls. I assembled the front section in the trailer.

I applied an industrial moisture-resistant coating to the outside edges of the wood. This includes portions in contact to metal surfaces . I paid special attention to sections where service doors are present; I'm probably going to wrap the floor edge with some thin-gauge aluminum.

I feel good about this project's results. I took a lot of pictures of work process and progress. If interested, I'm willing to share them but don't know how to copy/paste them to this forum.

Bob
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
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Razorback
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Re: Tips on bathroom Subfloor replacement

Post by Razorback »

It really sounds like you have done this repair the best way possible. I have to hand it to you on your diligence .

As for adding pictures, when you post a reply, down below the box where you are typing there is an "Upload attachment" tab. Click on that, navigate to where the pictures are, and add them one by one. In this forum, I think there is a 256KB limit? I don't remember, but you might have to resize the pictures to fit within that maximum file size.

Check out this topic... it discusses the attachment of pictures:

topic168.html
Razorback (Paul)
1987 Avion 34W
1995 Ford F-250 7.3L PowerStroke
I'm a "whosoever"... are you???
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