Suspended Floor advice

[momo]

Hi Folks,

I've just been to look at a couple of bathrooms and a cloakroom that need tiling. I'm only quoting for the tiling as the builder is doing all the prep work.

The house is Georgian and is being completely renovated.

There's a cloakroom on the ground floor that will be black granite. There's about 8sgm going onto a new concrete floor.

Upstairs there's two bathrooms. One will be ceramic on floor and walls. The other marble on floor and walls. Floors are 18mm ply on joists. These have been butted. Walls have been newly rendered with sand/cement except one which seems to be original plaster with paint on it.

They are installing underfloor heating throughout.

The client wants 1mm grout lines throughout.

I've already told them that I think they're pushing it with the grout lines and that the painted wall will have to be stripped/replastered in order to take the tiles.

I've also said that I think the floors should have ditra or similar to ensure waterproofing and to allow for temperature movement.

The builder says that none of the tiled areas are big enough to need that.

Since I haven't tiled onto underfloor heating before I'm getting a lot of my knowledge from the forum, and as far as I can see I'm right.

Aside from it being an old house, it has been unheated for months now and I'm a liitle worried about how much movement there will be when they finally bring it back up to temperature.

Another thing is that the ply floors have been down for some time and have had had all kinds of work being done over and around them. There's no bits missing but they've got very dirty.

I'd really appreciate any advice you have to offer on this. I'm going back in a week or so to discuss it further so I'd appreciate any advice you can offer and any suggestions as to what else I should be looking out for. I'd like to do the job but I'd like to do it right.

Thanks

[timeless john]

Momo - your talking Granite, Marble, 1mm joints, not having tiled over UFH before and a builder who knows it all!
Do you think you are out of your depth?
Why would you need to go back and discuss the job further - you could just get all your facts and submit your estimate the way you want it done.
IMO the forum can provide you with technical information of the correct preparation (which is what you have asked for I know) but there are other questions such as - how long has the concrete been down/the sand and cement walls been up/is it electric UFH?
I just get concerned that at times a basic knowledge of tiling is not enough and you can be leaving yourself open to big expense.
If I'am wrong then I apologise - but try and contact an established forum member near you to see if they can buddy you on this job - just a thought.
Good luck anyway and enjoy.

[doug boardley]

momo, you are asking the right questions, and if you don't ask you never know. Despite your inexperience you've posted some very valid concerns, well done. Stick to your guns and do not be bullied over by the builder, no compromise, you are the tiler, your way or the highway

[TF Ed]

hi momo

make a list of all your concerns... lead them to the forum regarding substrate prep, ufh, de-coups , grout joints etc if it helps reinforce your points to the client/builder.
tell them in writing on you estimate what your require to be done in order for you to carry out the tiling.

if they dont agree, simply walk away and dont take the risk because if any of the tiling fails, then its your name on the job and the builder will blame you mate, so tread carefully and stick to your guns, its hard out there and its tempting to want to get every job but theres times when if the sums dont add up, it aint worth it imo

best of luck and keep us informed.
ed

[momo]

Thanks all of you, this is sensible advice and I appreciate it. If anyone can add to it please do. There's a personal connection with this job so I want to be able to convince them to change their approach without getting into a ruck if possible. The more info I have from different sources the more likely that will happen.

[Mike]

as you say the concrete is down and the ufh isn't it must be electric. you'll best budget/advise them to cover all the cables with a good self levelling compound,(make sure it's compatible with wood floor, ditra etc.) this will be more expense but is necessary to ensure the cable are fully encapsulated in cement, prevents damage to the cable when tiling and gives you a good even surface to tile onto. good luck and don't be afraid to ask for help as a mistake can be very costly

[momo]

Just thought you might like to know how this story ended. The entire project came to a halt about two weeks after I started this thread. Money problems I think. Anyway, I've just heard that a scaled down version has just been completed and guess what? The floor was strengthened and the ditramat installed!

Once again thanks for all the advice. It made a difference even if it wasn't me who did the job.