SLC question

[Digger100]

As a rule of thumb , how bad does a floor have to be before you have to use SLC?

Got a conservatory floor to do and at the lowest point in the room to the highest point its about 15mm (gradual over a 1.5 metre span). Other parts had dips of 6/7 mm. Was hoping to back butter a few tiles to bring the level up to avoid using slc.

Any thoughts would be appreciated.

 

[DHTiling]

if the floor has dips etc... exceeding 3mm or so then would be wise to slc to get best results.............you can also use a pourable thick bed adhesive to over come small deviations...