Have i picked correct products for the job.

[bendy]

Hi there,

Just about to embark on a new tiling project for a bathroom i am installing at home. The floor and wall tiles are going to be Travertine and after reading about all the potential problems you can have i thought it best to quickly post on the forum to check i am taking the correct approach.

Floor

The floor space is 2.4m x 3.3m and covered with 4 x 4 (had to cut 8 x 4 sheets in half for access) 18mm structrual ply screwed on 8 x 2 Joists, running along the 3.3m span. Extra noggins have been fitted so the sheets are supported on all sides and i used 6 x 70 gold screws at approx 200mm centres. I have done a basic bounce test using a filled glass of water on the plywood floor at various points in the room and walked around and also bounced (although not physically jumped) and there is no movement of the water. Jumping on the floor causes a slight ripple for a split second. There are expansion gaps of approx 3mm between boards which i will be filling with silicon sealant. I believe i have two options:

1. Primer G on plywood, Keraquick with Latex plus and back butter the 12mm travertine tiles before installing.

2. Primer G on plywood, Durabase decoupling membrane, Keraquick and backbutter the 12mm travertine tiles before installing.

Are both options viable or am i taking a chance not using the membrane on that floor size?

Is Keraquick alone the best option over the durabase?

What would be the recommended notched trowel size to use?

What adhesive do i use to fix the durabase to the plywood.

What would be the recommended grout? The floor tiles will be tumbled so will not be sealed before installation.


Walls

3 walls are brick plastered and one is 12mm plasterboard on 6 x 2 studs. They will be primed with Primer G and the (brick walled) shower cubicle area will have liquid tanking applied. A corner bath will fit up against the plasterboard wall so i will liquid tank the area above the bath line that may see splashes of water from time to time. Tiling proceedure as follows:

Primer G on plaster & plasterboard, Keraflex Maxi white and back butter travertine tiles. Grout will be ultracolour plus cream. The wall tiles will be 'honed and fiiled' so will be sealed prior to installation.

Again, would notched trowel size is recommended?

Any advice on the above process and my questions would be greatly appreciated. I've had mixed answers from the few tile shops i have been too so thought this would be the best place to ask.

Many thanks

Ben

[nybor62]

i would go for a 10mm round notch trowel, back skim tiles for 100% coverage walls and floor you dont need to prime plaster board but it wont hurt,

one of the walls you say is plasterd, you may have a weight problem here 22kg a m2 if my memory derves me right. sure some one will correct me if im wrong , use the same addy to stick durabase down ok

[JLM Tiling]

As nybor said. Except think it's 20kg weight limit for skimmed plasterboard, 32kg for plasterboard. If it's on brick wall though it's gonna be render surely?

[JLM Tiling]

Also did you prime the bottom side of the ply? This is to stop moisture getting into the board from underneath and distorting it.

[bendy]

Many thanks for all your prompt replies and advice.

Three of the walls (approx 22 Sq/m) are brick work with a sand cement render of about 1/2" and then a 1mm plaster skim. The plaster has really taken well to the render and will need some real work to remove it. I'm thinking 6mm hardibacker or equivalent, adhered to the plastered walls with additional fixings.

What would be the recommended adhesive and mechanical fixings for fixing the hardibacker to the wall and what adhesive would i use between the hardibacker and travertine?

I've checked the floor again and discovered there is small amount of bounce (1mm, maybe 2mm ) in the middle of the 3.3m span when me and my 17 stone frame bounce up and down. I've concluded this is not suitable to lay the travertine down onto.

From your experience will overlaying with an additional 6mm of ply stiffen the floor up to remove this small amount of bounce?

As mentioned in my previous post i've stiffened the 8x2 joists up by adding additional noggins and the 18mm ply is screwed down at 200m centres. 5" kingspan is fitted between the joists tightly so i haven't really got the option to beef the joists up any more. If i can't find a solution to this bounce i may have to change the floor covering from tiles to a good quality lino

[Gazebo]

i would go for a 10mm round notch trowel, back skim tiles for 100% coverage walls and floor you dont need to prime plaster board but it wont hurt,

If you are using a cement based adhesive I was told you do have to prime plasterboard and plasterskim (gypsum products)

All good advice otherwsie.

[Mike]

6mm cement board won't be enough to get rid of the bounce. i'd use at least 10mm laid with spf and screwed every 150mm

[bendy]

6mm cement board won't be enough to get rid of the bounce. i'd use at least 10mm laid with spf and screwed every 150mm

Cheers Mike,

What make of cement board would you recommend?

If i'm going to screw down every 150mm, what thickness (notched trowel size) would i put the SPF down with? Would stainless Countersunk No.5 x 25 screws be ok or would i need something like aquapanel screws?

Ben.