Newbie Help

[snewo]

Hi Everyone,

I want to tile my bathroom floor. It's a small powder room (77" x 43"). The floor is 1/4" plywood overtop of 3/4" flakeboard ply over 16" OC joists. I obviously want to do this right so I'm looking for help. I'm trying to figure out the correct steps to take for an underlayment. Here is what I was planning on doing:

Buy 3/4" hardibacker style backer board and glue it to the existing ply with liquid nails and then screwed down to the ply with flat head screws, making sure the heads are below the surface of the backer. I can do the whole room with one board so I won't have any seams.


Does this sound reasonable, or am I making serious newbie mistakes?

What would you do if you were me?


Thanks in advance,

Snewo

[snewo]

I know it's bad form to answer your own post, but after reading the PDF in the Uncoupling Membrane Explained article at the top of the forum, it seems that I could forgoe the backerboard an do:

current wood floor -> proper adhesive -> uncoupling membrane -> adhesive -> tiles.


Is this doable? I'd like to keep the height of the additional layers as low as possible, but still create a good solid tile floor.

Thanks again in advance,

Snewo

[grumpygrouter]

By the tone of your post it would appear that you are "not from these parts". Measuring in inches and having something called Flakeboard ply. Not familiar with that I'm afraid.

The most important thing is to ensure that there is no movement in the floor. Your floor area is not large and your joists are at what we would term 400mm centres which is more than adequate. Do a little test - fill a glass right up to the brim with water and carefully place it in the middle of your floor. Walk around it and see if it spills over, if the water stays in the glass your floor is fine as it is. If your floor moves it needs strengthening. I suspect that your floor will be fine as it is and as you have a top surface of ply you should not need anything more. If this is the case, prime the ply with a good primer (ardex P51 for instance) and use a good single part flexy adhesive (rapid set if you are in a hurry) Ardex 7001 is specially designed for timber, another popular make here is BAL they do a lot materials that would suit you.

The uncoupling membrane (schluter ditra I presume) is excellent stuff but for your size of floor and construction you will probably not need it.

BTW welcome to the forums

Grumpy

[GazTech]

welcome from me snewo,in such a small area fastflex adhesive and wj grout with GT1 is best option...Gaz

[Varley]

I agree with grumpy, no need for uncoupling membrane in a floor that size, would be a waste of money.

[Dave]

If you are wanting to water proof the floor as-well use kerdi mat and bal fastflex adhesive..bal wide joint grout with GT1 additive...no need to increase the height with backer boards on such a small area..fast flex will suffice........dave...

[snewo]

Thanks for the information. Next time I'll dust off my metric units, thought I did use "English" units.




Snewo

[grumpygrouter]

Hi Snewo, didn't mean to insult .