Laying KARNDEAN tiles to a concrete floor.

[Silverloth]

Hi all,

This is my first posting here although I have dipped in and out in the past and found some excellent advice on various topics (thank you all) but I can't find specific advice on my current task.

Here is my situation:

I want to fit Karndean tiles to a ground floor room in a 1950s house, the floor is concrete, probably got no DPM but not damp according to a wee meter I borrowed, very snooth & level and no defects. It does however have a hardwood border about 40mm wide set level with the floor around the perimeter of the room, presumably to make life easy when fitting carpet gripper. Room is 2.6m x 2.1 m.

I'm quite happy with the measuring, trimming round sanitary ware, setting out and so on but the fixing is troubling me.

So, ply overlay, yes or no?

If yes, how thick?
Small sheets with a lot of cuts or biggest possible with fewest cuts?
How to fix ply to floor? (The concrete is VERY hard)
What adhesive to fix tiles to ply?

If no ply, what adhesive is best for fitting tiles direct to concrete?

Any advice would be most welcome,

Adam

 

[kjacko]

Proper Karndean fitters might give you chapter and verse on the 'according to Hoyle Karndean lore of fitting'.

However, i laid 35sqm of the stuff on my first attempt with karndean. It flowed through from the extension where the floor was concrete, then insulated, then chipboarded, then plyed. Then the ply joints were filled and smoothed with some stuff (can't remember the name)....to the kitchen which had been screeded smooth and the karndean was laid straight onto it.
So...i kind of covered both types of underfloor in one job i guess.
As long as it's level, smooth and CLEAN of rubble and small lumpy bits of dust etc, then you should be good to go.
The pro's can help better but i think you have to use a certain type of screed, if you go that route.
Problem you may have with ply is securing it to the concrete base without any chance of it raising at all.
Once your prep work is done, laying Karndean is quite a pleasure really, much easier than laminate flooring et al.

Hope this helps, sort of.