Returning retiree looking for advice

[Chris Griffin]

I was a regular on the forum before I retired nearly 5 years ago. I have to retile my on suite shower and not sure how best to go about it.. The walls have previously built out using marine ply and as I was unable to get the old grouting off when I found the sheets had only been nailed on and came off easily I removed them. I am unsure how best to proceed. The plasterboard behind is mostly good but has some holes I think this is from a much older job when the tiles were directly on to the plaster board before it was overboarded with ply. I was considering filling the hole with expanding foam and re-boarding with marine ply. If I do this should the ply be treated with anything before tiling? If anyone has any ideas for other options I would be interested to hear them. If anybody has a long memory I used to be a professional member under my business name - DoIt4U

 

[Flintstone]

Hello Chris,
Slightly confused about where you are at with this, have you took your tiles off? Ply wood is one of the least suitable materials to use in a bathroom, walls or floor.

 

[Old Mod]

Hi and welcome back to the forum Chris.
Re-board with tile backer boards like Marmox or Dukaboard, lightweight cement faces boards that are waterproof and cost effective.
Tank all wet area board joints and mechanical fixings. Overboard using screws and Wedi style washers. Min thickness boards 12.5mm just like PB,
but 20mm is more substantial if you have the room.

 

[Qwerty]

Welcome back! As he said ^^^^

 

[Chris Griffin]

Hello Chris,
Slightly confused about where you are at with this, have you took your tiles off? Ply wood is one of the least suitable materials to use in a bathroom, walls or floor.

I had taken the tiles off as the shower tray had been replaced with a shallower one as my wife has mobility problems. I was just going to add some ply in the gap left above the tray and retile but the adhesive was taking forever to get off so when I found the boards had only been nailed on it was easy to remove them.

You say ply is not suitable but what was on there had lasted 25 years and only had very minor water marks at the bottom

 

[Old Mod]

You say ply is not suitable but what was on there had lasted 25 years and only had very minor water marks at the bottom

Unfortunately ply available today is not of the standard of 25 years ago, it's very inferior.

No timber substrate is ideal, it's a natural product which is susceptible to outside forces, i.e. Heat, cold, wet conditions.
For example, if you don't acclimatise your timber correctly before tiling, that alone can cause boards to shrink and cracks open up and this can transfer thro the tile.
Tile backer boards are made of inert materials, and are not subject to these types of problems.

 

[Chris Griffin]

Unfortunately ply available today is not of the standard of 25 years ago, it's very inferior.

No timber substrate is ideal, it's a natural product which is susceptible to outside forces, i.e. Heat, cold, wet conditions.
For example, if you don't acclimatise your timber correctly before tiling, that alone can cause boards to shrink and cracks open up and this can transfer thro the tile.
Tile backer boards are made of inert materials, and are not subject to these types of problems.

Thanks I will look into that.