Prep questions regarding tiling a small bathroom floor...

[John the tile]

Hello all

Im tiling an upstairs bathroom wooden floor. Ive not done a floor onto wood before but as long as I know exactly what Im doing im confident I can do it no probs,.. Ive been doing lots of research and have some questions.

The floor is at the moment chipboard. There is deflection (bounce) and creaking (loose nails). I do not know what thickness the chipboard is. Im guessing its either 18 or 22mm thick. The house was built in the last 15 years.. The bathroom will be empty no bath suite in...

1) Does the chipboard defo need to come up.? ( floor less than 2 square meters).

2) What is the purpose of 18mm wbp ply. Is it to make the floor have no bounce and be more rigid??? Does the chipboard not do this if its securely fixed?

3) What are the purpose of the noggins at every 300mm and at the joins/cuts of the 18mm wbp plywood? Is it also to make the floor have no bounce and be more rigid???

3a) What are the correct screws and does it matter how many I use ( the more the better?)

4) What are 6mm Hardie backer boards purpose - to make a stable surface to tile onto? What does stable mean?

4a) Do I HAVE to use hardie backer boards. Will it not be ok to tile onto the 18mm ply? Even without the hardie backer board the floor will be 15mm TOO high.....

5) Are chipboards easy to saw through with a normal hand saw whilst their on the floor? (dont want to buy an expensive circular saw just yet)

6) Ive read to primer UNDERSide and edges of 18mm ply. Why is this?

7) Is mapei G ok for the priming and what about the upper side?

8) Is mapei flexi rapid and ultra colour plus ok for the grout and addy. (ceramic tiles)

9) What are the ideas and suggestions for the floor being 15-20mm higher than the carpeted hallway? Is there a seperation floor strip I can buy?

Thanks for any answers to the above...

 

[Ian]

Crikey thats a lot of questions! Try to screw the chip board down first to get rid of the deflection, if this doesn't work, it'll need to come up and be sorted, 18/22mm ply would be the best replacement. Whichever of these 2 routes you go down I would still overboard with cement board (glued and screwed) to give a more suitable surface to tile to. There are door bars that can be used to overcome any height transition at the door.

 

[The Legend; Phil Hobson RIP]

Ditto as Bri, for me.

 

[Turkish]

Hi Golddigger

I`ve just removed my floorboards to strengthen the floor underneath using noggings, this will and has ensured there is no bounce in the floor. I then laid 18mm wbp ply screwed every 30mm and i used turbo gold screws which you can get from screwfix. Then I overboarded with 6mm hardiebacker laying it on a bed of flexible cementious adhesive then screwed down with hardiebacker screws ensuring the joins of the hardiebacker don`t run in the same line as the ply underneath. Going back to the ply I primed the sides and underneath with BAL BOND SBR to prevent moisture from underneath. I also siliconed the joins between the ply. As for height there are various tile to carpet trims that take into account some height difference but not sure what their limit would be. Maybe you could consider something like quadrant type trim to take up the difference?

Hope it helps anyway. good luck!!

Turkish

 

[John the tile]

Yeah, sorry about so many questions. Its just infomation Ive found out through trawling the web and just like to know what Im talking about and all the details and how long things will take before starting the job.... I think I know most of the answers but alot of them I just need some definate clarifications from the pros.

Some of the questions were answers above so thanks so far guys...

Another question - I thought WBP ply was moisture resistant? What moisture would get to the bottom of the boards?

Thanks

 

[Rich]

Sound advice above, the underside of the boards are seald to give some protection from underneith, water leaks and jut humidity and temp changes from rooms below can be enough to make the ply swell and contract causing the tiles to crack and lift.

As above, I would see if I could get the chipboards deflection free (providing that it is not water damaged) first but screwing it down (not nailing), if it needs to be replaced then BWP ply is your best bet and then a cement board. Basically all the prep work that you do before the tiling is to make the floor as rigid as possible, ANY bounce in that floor and you will have loose tiles and cracked grout (not to mention a very unhappy customer). The cement boards give a really good surface for the tile adhesive to bond to, unlike ply whick can be problematic. Have a look through the link below for a little bit more info.

[h=3]Plywood floors...[/h]

 

[John the tile]

Thanks Rich.

Bal Bond SBR is this especially for plywood only or can it be used as a normal primer for the walls.

The cementious adhesive used to glue the cement board down, does it matter which type/brand?

Thanks

 

[Dovey83]

Check out this link BAL Adhesives - Products - bond SBR then click on the product data sheet in the bottom right hand corner.

Hope this helps

 

[Rich]

It doesnt matter which brand of adhesive you use as long as it is suitable (single part flexible adhesive is usually recommended by the board manufacturers), most of the time I use the same adhesive that I am going to tile with as I tend to use a single part flexi adhesive for most insatllations.

 

[codenamepj]

Rich.. your the man when it comes to this game! I came on here for advice so I could do my bathroom myself but I want you to do it! were R U from.. please say within distance to work in Lancashire?!?

Pete

 

[Gazzer]

Rich.. your the man when it comes to this game! I came on here for advice so I could do my bathroom myself but I want you to do it! were R U from.. please say within distance to work in Lancashire?!?

Pete

Bit far for Rich but you wont get better than this man View Profile: Phil Hobson - tilersforums.com | Tiling Forum | Wall and Floor Tiling Forum | Tile Forums | Tilers Forum