first post and need help on 50 sq mtrs of 20 mm limestone

[sking]

hi everyone first post

i start a new job tomorrow i know im leaving this late
but here i go
20mm thick limestone 800x400 600x400 200x200 (roman classic opus design) i have layed 12mm thick wedi board down over 22mm thick chipboard and using bal tile and stone ady
the question i have is what size of trowel do i use
been told a 16mm is ok but also been told 12 mm is ok
the tiles have a grove on the back of them, do so do i fill them up with ady as in skim the back of them

 

[Gazzer]

Back skim the stone. 16mm....oooooer thats a big un !
12mm should be fine.

 

[Dougs Third Go]

sounds like bastille, as above, back skim and a 12mm solid bed trowel will do you.

 

[Dougs Third Go]

just to clarify, do you mean 12mm radius or diameter?

 

[sking]

thanks guys for the quick replies
i have a rubi 12mm notched trowel

 

[Dougs Third Go]

is it a square or round notch trowel though sking?, a round (well semi round to be precise) will give you a solid bed as where a square notch won't (unless you really wiggle the tile to collapse the adhesive ribs)

 

[sking]

its a square notch
i do have a 10mm round
what about if i put a 10mm semi round bed on the floor and say a 6mm on the back of the tile running across the ridges

 

[Dougs Third Go]

its a square notch
i do have a 10mm round
what about if i put a 10mm semi round bed on the floor and say a 6mm on the back of the tile running across the ridges

no, you'll be cross bonding and get air voids, use your 10mm semi round and back skim the tiles using the flat edge of your trowel, this should give you a 100% contact.

 

[sking]

any thoughts on why i was advised a 16mm bed was the person just going ultra safe to give me a solid bed of ady


o no i have bought far too much ady (30 bags) as i thought i was fixing it down with a 16mm trowel and was advised i would only get about 2 to 2.5 sq mtr out of a bag

 

[Gazzer]

Its a bit overkill IMO unless the floor was really bad.

 

[Dougs Third Go]

quite possibly your advisor thought that you'd be laying uncallibrated stone, hence the need to build up on the addy.

 

[sking]

aw well guess ill be using bal tile and stone ady for a while

so to recap a 10mm bed of ady on floor with a 10mm semi round trowel ,skim back of tiles with flat edge of trowel and bed down

 

[Dougs Third Go]

yep, give the tiles a wiggle as you bed them, you want them there a long time so may as well make them comfy