www.ultimatehandyman.co.uk

Hi,

I've seen the tables showing that plaster can only take up to 20kg mer sq metre (which is a little different to what a bloke told me at a tile shop at the weekend, when he seriously said 400-500kg!! I laughed my arse off!), but am stuggling to find tiles which are comfortably under this. It seems that ceramic 8mm, with adhesive and grout, is around 20kg (from looking on the internet).

Is this just being on the safe side? I can't see everyone using 6mm tiles just to get the weight under? Am I getting my knickers in a twist over nothing?

The tiles I've seen are 20x50cm 8mm ceramic. The box I think said something about the weight not exceeding 22kg (the box was 1.5m2), although the writing was mostly in a foreign language. So should this be okay?

The more you read up on things, the more there is to go wrong. Oh to be totally niave.

PS - I will be using bagged adhesive for this.

Thanks!

Maths is a bit hard in my head right now lol.

Yes that would come under the limit which is as you stated.

That is as long as it is finish plaster and not backing plaster.

Could you get away with more weight. The TTA have written guidelines. Some of them vastly under what reality shows. The worst bathroom (been done donkeys years) we ripped out that should have killed about 200 people with tiles falling every where; Originally half tiled, top half painted in distemper. Later thin tiles were added to the top half. Then later still the top half was plastered over the thin tiles to make it flush with the bottom half. Lastly large format tiles were put over the whole lot of it. They also had features done in 3mm ply, OSB in places. Job was a pig to strip out. Their other bathroom was exactly the same.

The 20kg on skimmed plaster is a guide weight. In reality well bonded plaster will take more, equally poorly bonded plaster will take far less. So 20kg is taken as a guide line as is all other recommendations in BS5385.

It is up to you to assess how stable the substrate is. Tiles are getting larger (larger tiles are often thicker hence more weight)and people are becoming more daring with their choices so whilst some people bang on about 'I've never had a problem in 30 years' the tile market is changing and so are fixing methods.

If you stray a few kg over and the plaster is well bonded you are unlikely to have a problem but once you start getting in to the high 20's you may want to think about what you are doing.

It is generally accepted that the weight of adhesive used is based on 5kg per sqm when you work out your overall weight.

The box may be generic and it isn't the weight at all but a statement that it meets H&S limits on maximum weight of that box. If it is the actual weight of the tiles then you are just slightly under the recommendations of 20kg on skimmed plaster anyway.

royaloakcarpentry wrote:The TTA have written guidelines.

It's not the TTA's guidelines, it's British Standards which the TTA follow

They are also written on the TTA site lol

Cool, thanks.

I may well be a plonker and take in a set of bathroom scales when I buy them!

It's my skim. I hope it bonded well or it's only me to blame.