Cement Boards 101?

[TommyGun]

Good morning/afternoon/evening all!

im currently in the middle of converting one of our spare rooms into an en-suite bathroom. im using travertine tiles for both the floor and walls (the floor is already tiled). ive been gifted lots of 6mm Hardie cement boards. ive never really used these sorts of boards before so i am just looking for general fitting advice.

1. firstly is 6mm boards going to be strong enough to support the weight of all the tiles/adhesive/grout?
2. if so, what is the prefered fixing method of the boards to the wall? the instructions say to lat the wall (are something like the size of roofing lats strong enough?)
3. if and when it comes to sealing the cement boards is a good silicone good enough to seal the edges of the boards rather than using that tape stuff?
4. allegedly BAL white star is a good adhesive to use. is this true? and/or what other adhesives would you guys reccomend?
5. and finally what would be the best way to bed the adhesive to the walls? a 6mm notched trowel

i dont know if it helps, but 3/4 of the walls are old plaster (painted) and the last wall is a stud wall that i put up. i dont think knocking the old plaster off would be of any benifit as its a 200 year old stone house and all the stonework will not be level at all. sorry for all the stupid questions, but im not a proper tilier but i do have tiling experiance (only on floors) and i would like this to be done properly (or as properly as i can do it anyways :lol: ). i can provide pictures if ive not really been clear, i know im terrible at explaining things.


many thanks in advance. Tommy :sofahide:

edit: i forgot to mention. the plumbers merchant is selling mahoosive travertine tiles (my guesstimation is 600x450) for £4 a tile is that a good or bad price?

 

[Alan.P]

Hi TommyGun, welcome to tilersforums.com

Too many epic fails in your post of intended works, is this room downstairs ? In my very humble opinion you would be better off getting a Professional in. Basically everything your planning on doing is wrong, from substrate to adhesive.

Sorry to be the one to tell you.

 

[White Room]

Whats Lat the wall??

 

[judge]

Trav from a plumbers merchant.....................hhhhmmmmm!!

 

[TommyGun]

Hi TommyGun, welcome to

Too many epic fails in your post of intended works, is this room downstairs ? In my very humble opinion you would be better off getting a Professional in. Basically everything your planning on doing is wrong, from substrate to adhesive.

Sorry to be the one to tell you.

lol, thanks Alan for the reply. i would much rather someone tell me im doing it wrong than not. the room is upstairs (the joists are 8x4 at 400 centers if that helps) would you care to elborate on what exactly im doing wrong. according to the manufactures instructions it is possible

MASONRY WALL INSTALLATION
HardieBacker® EZ Grid® 6mm Cement Backerboard should
be used on top of masonry walls. Maximum load carrying
weight is 100kg/m2.



from what they are saying it is possible, all i was proposing to do was to negate the glue but instead of, making in essence a stud wall anchored by 100mm screws, which in my expericence is a hell of a lot stronger than some polyurathane glue on ~50 year old plaster

mr. whitebeam 'lat the wall' is making a faux stud wall on a wall

it wont let me post the jameshardie installation guide available on their website

 

[Alan.P]

Hi TommyGun.

Ok, if I'm reading this right, in order

Your floor is tiled already and your planning on tiling over this, what is the floor type, tile type and how well are they fixed.

Timber frame for the wall will have to be better than roofers lat, I wouldn't use it, don't like it.

The stud wall you've built, what is it constructed of, if plasterboard it will either have to be over boarded or re-boarded.

All joints as well as internal and external should be taped.

Not sure who / where you heard Bal White Star would be ok for Stone, it is NOT, don't use it. Use a powdered adhesive suitable for natural stone.

For that size tile I would use a 10mm ( minimum )trowel and backbutter the tile as well.

The price is excellent, unfortunately the tile won't be, you get what you pay for.

Others may have / will have other input, hope that helps.