Floor tiling / floor make up questions

[ProDave]

I am about to start laying the floor make up and then tiling my hall and utility room floors.

 

The rest of the ground floor has a built up floor with biscuit mix UFH between battens and engineered oak floor.  The finished level of the tiles has to match this level.

 

I have bought a whole load of slate tiles.  In spite of being described as "calibrated" there is quite a difference in thicknesses. So in some places I will have to be laying a tihck bed of adhesive, and others not much at all.

 

So the immediate question is what floor make up to get to the level I want?

 

I have mocked it up with a sheet of 22mm P5 chipbpard then a 12mm sheet of plywood.  Taking one of the thicker tiles that only leaves about 3mm for adhesive to get the tile to the finished level, but taking one of the thinner tiles that will easily allow for 6mm of adhesive.  Is that about the right thickness to be aiming for or would a thinner floor makeup and thicker adhesive be better?  i.e what is the min and max adhesive thickness?

 

Is 12mm ply okay, or would I be better going for say 18mm P5 and thicker ply to get the same overall thickness?

[AliG]

I think that a tiler would tell you to use adhesive roughly as thick as the tiles, so around 10mm on floor tiles.

 

This always seems way more than I would expect and I know that people do get away with less.

 

It might be worth using tile backer board where I think you can go thinner than with ply.

 

This seems like a good article about it.

 

https://ukbathroomguru.com/tiling-on-wooden-floors-part-4-overboarding/

 

 

 

[ProDave]

As it happens I have started this.  I laid the first batch of tiles on Wednesday.

 

I then hit a problem yesterday when trying to lay out the next section, the modular tiles I have are not cut accurately and arguably cut to the wrong sizes, this results in some tiles needing a tiny sliver cut off them.

 

At this point I have shamefully admitted defeat and my friend John the Tiler is coming today. The main advantage is he has a better tile cutter than me and a lot more patience.  But I am almost ashamed at having to "get a man in"

[CC45]

at least you sought therapy early on - the cure is far more likely to be effective & cost efficient now.

 

I to have done the tiling everywhere else except the ground floor - too big an area that would take ages (I work full time) and I just want it done now.

 

Good on you.

[AliG]

The professional's tools often give him a big advantage.

[ProDave]

That's the entrance hall tiles down today.

 

 

This won't cost me directly, I have some electrical work to do at the tilers house on a labour exchange basis.

 

I will try to explain the sizing issue.

 

The largest tiles are a nominal 60cm by 40cm.  Where it works out in the pattern that a 20 by 20 plus a 40 by 40 tile adjoin a 60cm tile, the problem was the 20 by 20 plus the 40 by 40 put tight together were exactly the length of the nominal 60cm tile, leaving no room for a grout gap.  A lot of criticising of the "rubbish tiles" ensued today, following by a lot of trimming tiny little slivers from tiles.

[CC45]

aren't paving slabs like this with regards to size?

 

Looks good.

[ProDave]

Hope to get it all cleaned and sealed tomorrow and SWMBO will grout it on Sunday.

[ProDave]

Taking shape slowly but surely.

 

The entrance hall is finished and grouted.  Working on the utility room now that is a bit more fiddly.

 

You can see in the hall I am part way through building the coat, shoe and hat storage.

 

The utility room is more fiddly as it incorporates under floor heating set into the chipboard layer,  I need to fill that new loop with water and pressure test it before covering any more of it with the plywood later.

 

Then it's get the plasterer to plaster the room, paint it, and then get the tiler back to tile the utility room.

 

Scottish building regs require that you make provision for a downstairs shower.  Our provision for that is we could divide the utility room to make a shower room.   The drain for it is laid under the floor. This drawing documents it's position, and a gap left in the under floor heating.

 

Should we need to fit a shower we would need to break out 1 or 2 tiles, cut an access hatch in the floor, fit the drain, and re tile.