How Much Old Adhesive Needs To Come Off

[mmmadman]

Hi All

I have just removed the old tiles from two of my small bathroom walls (plastered plasterboard) and scraped all the loose addy off.

How much of the old addy has to come off, the stuff still on is stuck solid and about 2-3mm thick. I am re-tiling with large tiles 415 x 300...?

Cheers.......:8:

 

[Alan.P]

What tile type is it your going to fix, odds on that they are going to be too heavy for skimmed walls, it might be a case of over board or strip off the old boards and re-fix new ones.

 

[mmmadman]

Ceramic, about 8mm thick, they weigh approx 5lb each, and as I said 415 x 300 = 8 per Msq = 40lb per Msq or approx 18kg per Msq + addy, is this too heavy.................?????

Many thanks...........

 

[Alan.P]

Borderline to just over, depending on trowel size, if your walls are good I would be using a minimum of a 6mm, if you do leave any old adhesive on your going to have to go to an 8 +, there's a guide to weights here.

EDIT: As you can see, beneath the tile weights there's a substrate weight list, plaster comes in at 20 kg pm2

 

[mmmadman]

That's great thanks, I am now using a wallpaper steam stripper and the old addy is coming off now, slowly.............lol...............................!!!!!!

The walls are dead flat so 6mm trowel it is...........!!!!

Cheers........

 

[Alan.P]

That's great thanks, I am now using a wallpaper steam stripper and the old addy is coming off now, slowly.............lol...............................!!!!!!

The walls are dead flat so 6mm trowel it is...........!!!!

Cheers........

As long as you realise you are borderline and can sleep at night, are you sure you wouldn't rather rip off the existing board and plaster and reboard, for peace of minds sake ?