Replacing "Shower Board"

[Rob Gray]

Someone posted about this subject a few weeks back and I have some more questions. I am getting ready to replace the "shower board" material (material is a composite board material with a waterproof shiny front that looks like tile) in a shower in my family's vacation place. The existing board was put in about 25 years ago and it has worked very well but needs replacing. I bought the new board at Home Depot and the adhesive they recommend using. I have a few questions on installing this stuff though, as follows:

1) The product comes with plastic border strips both for seams and corners. Do I also need to use bathroom sylicone sealent along all edges for water-tightness?

2) Someone here noted to be sure the board does not touch the tub, but that I leave a slight gap to avoid the water "wicking" up into the board. How big a gap do I leave?

Any other suggestions would also be welcome!

Rob NE PA

[AZGuy]

I would use something but not silicone based, or at least not "pure" silicone types. I just did a bathroom and the silicone sealant would not stick to some of the plastics and just made a mess of things.

I've never heard that before but I can see the reasoning behind the suggestion. Even so, I would not leave a gap if I was doing it. Do you really want to leave a gap where bugs and dirt/dust can get into your living space from behind what will inevitably be a somewhat moist inside the wall area? How's the wife going to react when spiders start coming out during her shower? And if you leave a gap you will be insuring that moisture can get up into the wall even if only from the "Fog" when using the bathroom/tub/shower. I'd make it tight and seal it. Even if you leave a gap I would suspect that over the long term you'd wind up having to run sealant in there anyway.

-- Elbridge Gerry, of Massachusetts:

"What, sir, is the use of militia? It is to prevent the establishment of a standing army, the bane of liberty. . . Whenever Government means to invade the rights and liberties of the people, they always attempt to destroy the militia, in order to raise a standing army upon its ruins." -- Debate, U.S. House of Representatives, August 17, 1789

[Roger Shoaf]

The tile board is fine as ling as there are no scratches in the shiny finish. If there is the slightest scratch, the moisture will get into the masionite below and the shiny stuff will peel off leaving an ugly brown spot. Might I recomend using FRP's? These are fiberglass reinforced panels. They will cost about $5 to $10 a sheet more than the tile board, but stay shiny even if they get a little scratch.

Depends what your shower pan or bathtub is made from. Pure silicone is good if you are not trying to seal it to a polyethylne or polypropeline surface or you intend to paint the caulk. If you have a fiberglass or procelin base or tub and are not going to paint the pure stuff works well.

About 1/4 of an inch. If you usw tile board besure to have a continuios bead sealing the edge of the masonite.

I didn't leave a gap, and I wish I did. A little bit of moisture seeps in and poof you have a big ugly. The gap prevents wicking.

[AZGuy]

Maybe I mis-understood what was proposed. From this latest post it sounds like you are still sealing the "Gap" with sealant. So to me that's not a gap the way I was thinking of it. The sealed gap would seem like an ok way.

-- Elbridge Gerry, of Massachusetts:

"What, sir, is the use of militia? It is to prevent the establishment of a standing army, the bane of liberty. . . Whenever Government means to invade the rights and liberties of the people, they always attempt to destroy the militia, in order to raise a standing army upon its ruins." -- Debate, U.S. House of Representatives, August 17, 1789