Tanking

[marsaday]

Hi there

I understand from reading the stickie i will need to tank my plasterboarded walls. They are skimmed and that is all at the moment.

The rear wall in the bathroom is where the shower will be and i want to tile the full wall right up to the ceiling. I have used cement boards where the shower will be.

1) Do i need to tank the cement boards

2) what product do i use to tank this wall ?

3) Should i tank the wall around the bath area ?

 

[Richard C]

I understand from reading the stickie i will need to tank my plasterboarded walls. They are skimmed and that is all at the moment.

Only need to tank in “wet areas” but did you use Moisture Resistant plasterboard? you should in a bath/shower room or kitchen.

The rear wall in the bathroom is where the shower will be and i want to tile the full wall right up to the ceiling. I have used cement boards where the shower will be.

1) Do i need to tank the cement boards

Some tile backer boards are fully waterproof & some are classed as moisture resistant but either would be OK without tanking for showers & around baths; only time you should consider tanking these is when creating a wet room.

2) what product do i use to tank this wall ?

As above, you won’t need to but for the PB walls, this will probably be the easiest product for you to use;
http://www.bal-adhesives.co.uk/products/waterproofing-kit

3) Should i tank the wall around the bath area ?

If it’s just plastered plasterboard you should tank it or it could fail in a very short time.

 

[marsaday]

Reading some bal info it seems i do need to apply a primer - bal prime to the new plaster, just in case it is too polished.

So this looks like what i need to go for.

 

[Richard C]

Reading some bal info it seems i do need to apply a primer - bal prime to the new plaster, just in case it is too polished.
So this looks like what i need to go for.

Did you not read my replies to your other thread?
//www.diynot.com/forums/viewtopic.php?p=2037747#2037747

Your better not to use a primer unless you really have to as it will affect initial tile adhesion; if the plaster is over polished it will be extremely shiny, use some sandpaper on it. However, with large tiles you need a cement based adhesive so you must prime with BAL Prime or Prime APD.

 

[marsaday]

Ok, so if using cement i need to prime, but if using normal tile adhesive i had best not prime.

yes i read your other thread thanks.

dont most houses have a plastered wall and then they load it with natural stone. I am really surprised i could over load the wall.

I will try and get 8mm thick max if i can.

Are there any alternatives to natural ? Is limestone a good option in terms of weight ?

 

[Richard C]

dont most houses have a plastered wall and then they load it with natural stone. I am really surprised i could over load the wall.

You’re not overloading the wall that will never fall down as a result of tiling, your overloading the bond strength of the plaster to the wall (substrate). Any base has a limit up to the strength of the adhesive you’re using, exceed that to any degree & the tile weight will pull them off the wall; it’s just unfortunate that many just don’t appreciate that plaster is the lowest of them all. This was never a problem with the 6” x 6” x ¼” Crystal” tiles of yesteryear but with the modern trend for large format & natural stone tiles, plaster is the very last thing you should be using as a tile base.

But don’t take my word for it, do some searches & you will find that the figures actually come from British Gypsum (who make plaster) & the Tile Association (who advise on tiles); presumably as a result of the ever increasing number of failures resulting from using such tiles over plaster!

I will try and get 8mm thick max if i can. Are there any alternatives to natural ? Is limestone a good option in terms of weight ?

Tile thickness is a general guide to the sq/m weight & doesn’t always follow depending on the type of tile you chose, you need to know the weight per sq/m of the tiles your laying.

 

[marsaday]

Righto, i will try and find the weights out when i buy them.