Great Big Hole!

[MelNSTO]

Removed some drawers in our "new" '77 Minnie Winnie to clean them today, and discovered a huge hole in the flooring under the sink. I can see the wheel, the exhaust pipe and the ground. I'm no carpenter, but need to repair this. Where do I start? What's involved?

There are no RV repair places within 75 miles of us. Also, temperatures are hovering around 10 degrees.

Any help would be highly appreciated.

[Hipshot]

Can you put a piece of plywood over it till you get home? Lowes and Home Depot will cut the plywood to your measurements.
Good Luck

[Senior Chief]

Sounds like a long-term leak under the sink rotted out the flooring.

Not much involved- there are many places on your Winnie where there is just one layer of plywood over the framing. The floor under your sink area is probably not a vital part of the superstructure, so a hole there is just a nuisance.

Take a pocket knife and stick it in the floor to find out how far the soft area extends. Then cover the entire soft area and part of the firm area adjacent with plywood, as Hipshot, suggested, and secure with deck screws every few inches in the firm wood.

If the soft, rotted wood extends out into the aisle, you have a more extensive problem- not more critical, just more work to patch.

[wa8yxm]

First how big is "huge" I mean 3 inches is one thing 3 feet another.

Likely you will take a slab of plywood, and perhaps a slab of either metal or plastic or plywood, make a sandwich, screw up from below and fill with expanding foam, lay the top one on and screw it down, Since this is a place that is "out of sight' no need to be neat. But I'd like to know what caused it.. The heavier the cause, the heavier, Most likely the bottom plate. You may need to trim out rotted wood too.

All wood should be sealed and painted BEFORE attachment.

[QuietWater]

Is it possible that some time in the past there was a tire blowout that may have beat the floor out? I've seen that happen.

[Forest Grump]

I had one the size of a 3" rock behind my back wheel. A previous owner had a sheet of aluminum screwed to the aluminum undercarriage into the wood, leaving the jagged edges of the wood on the inside of the basement compartment. I took a hammer and beat them back in, I wanted them. I then took a special clear epoxy used to repair wood rot and mixed up about a cup. To this I blended in birch sawdust from the local cabinet factory to make an epoxy mix comparable to a cake batter. Poured it into the prepared hole, leveled it with tapping on the bottom aluminum patch and did my best push the carpet back over it. Once set, give it 24 hours it can also be sanded and is stronger than the original plywood and one with the original plywood because it penetrates the plywood including the hammered splinters. It is also flexible.

Have a log home so I am very familiar with repairing wood.

[ronspradley]

I read on a wood working forum that wood rot, dry rot is caused by a fungi and that auto anti-freeze (ethylene glycol) will kill that fungi. I have not tried this yet but it is on my list.

ronspradley

[Forest Grump]

There are commercially available copper compounds which are excellent fungicides and will penetrate the wood. They are also compatible with the epoxy resins. These epoxy resins are used to make surfboards and wire stitched kayaks.