Moldy Particle Board on Toilet Platform

[Doug C]

I recently posted about a toilet leak. I've since replaced the leaky valve on the back of the toilet. The toilet is in the garage ready to install. Thanks for your help on that part.

My problem is that the piece of particle board that the toilet sits on is moldy on the top surface and underneath surface. Plus the particle board on the face of the raised platform that the toilet sits on is swollen at the bottom from moisture. The whole affair is solid enough to get by, but I'd like to do it right and replace the whole particle board "box" or "platform" that the toilet sits on with 3/4 inch painted exterior plywood. Are there any pitfalls I should be aware of before I go for it? The only part that looks a little iffy to me is where the downpipe from the black plastic toilet flange goes into the mouth of the holding tank. It looks like it is sealed with soft plumbers putty. Once I release that big hose clamp is there any problem getting the downpipe out of the holding tank mouth, or getting it back in.

Or should I just leave well enough alone, wipe things down with bleach, install the repaired toilet, and call it good.

Thanks for any advice.
Doug C.

[perryg114]

Saturate everything with bleach preferably in a spray bottle and then use fans to dry out the wood and see what you have left. If you don't have severe rot you can paint the old particle board to protect it and seal it off.

Perry

[tphan]

I think your idea to replace it with exterior-grade plywood, or marine-grade plywood, is a good one. Once you pull out the deteriorated particle board, follow perryg144's advice on any other suspect areas that would be difficult to replace, followed by mold and stain inhibiting Kilz paint once everything is super dry. I would also give the new wood a coat of Kilz, both inside and out. Mold is your enemy!

[Protagonist]

Originally Posted by Doug C

The whole affair is solid enough to get by, but I'd like to do it right and replace the whole particle board "box" or "platform" that the toilet sits on with 3/4 inch painted exterior plywood.

Since you say the particle board is damaged anyway, might as well replace it, and get rid of the mold at the same time.

However, instead of exterior plywood, I'd recommend using "marine grade" plywood such as is used in boatbuilding. The main difference is a different grade of glue holding the plywood together, that is even more resistant to moisture than exterior plywood. On the other hand, you'll pay more for it…

<edit> As soon as I posted this, I saw that tphan beat me to it. So I second his recommendation.

[Doug C]

Well, I pulled out the platform that the toilet sat on and the carpet and padding that was underneath the platform. I'm planning to replace the carpet in the bathroom with vinyl and build in a better toilet platform with a usable access door for the area under the toilet. The way it was built, I had to take the toilet out and pull back a bunch of wet carpet just to access that area. So now the job is bigger than imagined, but at least the area will dry out, and I can hopefully put a stop to the mold. I'll also be better able to monitor the area for leaks and stop any that happen in their tracks! I never would have guessed that an Airstream would be built with OSB subfloors and a particle board toilet platform, which was then covered with carpet and padding. I thought these trailers were of the very highest quality? Why not use marine plywood for subfloors and toilet platforms? I know it would add to the cost of the trailer, but not that much. The construction labor would be the same as using particle board and OSB. Live and learn, I guess.

[TG Twinkie]

The toilet flange screws into the tank. Righty tighty, lefty loosey. Make a spanner wrench with a piece of flat stock 1/4" x 1" x 12". Place bolts thru it at the same distance as the notches in the flange. Hold it tight against the top of the flange and turn it like a wrench.

[danlehosky]

Think about replacing this platform with solid surface material like Corian or similiar products. You can cut or have the peices cut to suit your needs and the ficx will be permenant and sanitary. I have actually run this material through a surface planer and router. It's easy to work with and will give you a nice clean job that will withstand years of abuse.
Dan

[Doug C]

Originally Posted by TG Twinkie

The toilet flange screws into the tank. Righty tighty, lefty loosey. Make a spanner wrench with a piece of flat stock 1/4" x 1" x 12". Place bolts thru it at the same distance as the notches in the flange. Hold it tight against the top of the flange and turn it like a wrench.

Thanks for the tip, but your description doesn't match the way this particular trailer (1992) is put together. I might be misunderstanding. The toilet flange on this trailer screwed to the top of the particle board "platform" or "box" that the toilet sat on. Dismantling the whole thing down to the trailer floor required only normal common tools. The flange connection at the top used a philips screwdriver. The connection from the holding tank required a deep socket (7/16" ?) and 1/4" ratchet. Nothing screwed into the holding tank. There was a large hose clamp there. Thanks for answering though. I appreciate all feedback. I might be missing something here.

Doug C.