Floor Advice

[Mikeclem]

Hi Chaps,
So I have started my first ever tiling job. I had a porch built a year or so ago and after missing a failed deadline to get it finished for Christmas last year I have committed to completing the job before the big day this year........I was bit apprehensive as I've never tiled anything before and was close to getting someone in but figured that I would have a go to see if I could learn the basics along the way. So far I have quite enjoyed the challenge, however I have hit a snag that I can't decide what the best course of action is to rectify.

The concrete slab was OK but had numerous ridges, dips and high spots so after reading about I bought some Norcros Pro50 Self Levelling compound and put that down. It was pretty straightforward no real drama's. I checked the floor level after self levelling and have found that although the floor is a lot smoother to look at it has a dip towards the middle. There are areas that are raised, more like high plateaus than high spots, these are by the front door where the slab met the inner leaf of the cavity wall and at the opposite side. The floor tiles I have are Casa Dolce Casa wooden effect, they measure 1.2m in length and have 3 width sizes, a friend gave me these as they were left over from a big job, turns out I had exactly enough to cover the floor. My dilemma now is what to do about the floor level, should I get a concrete planer and take down the high areas or should I try to raise the center of the porch floor. It measures 5.2m2 and the run out from one end to the middle is 14mm. The high areas are about 10% of the total floor so I can't decide what is the best way to level the floor, work on lowering the 10% high areas or raising the 90% lower areas.

I have been advised to trowel with an 8mm notch and bed the tiles in to give about a 6mm adhesive bed, also was advised to back butter the tiles. Does anyone think the tile levelling systems such as Rubi would be useful here?

Any input here would be appreciated, like I said I am happy with the progress so far, although it's taking some time, I just want this job to be right and have read quite a few horror stories about tile lip and adhesive slump so want to give this job the best chance of being right first time....... I've attached a couple of pics to try to show what I am rattling on about.........turns out I can't attach a pic? anyone know how to on this forum?

Cheers

Mike

 

[Just Rizzle]

hi mike can you tell me how thick is your concrete slab and has it got a insulation layer

 

[Mikeclem]

Hi, it has celotex insulation layer, and if I remember correctly it is about 125mm thick, I just text the guy that cast it he'll reply as soon as he can, why do you ask?

Thanks

Mike

 

[Just Rizzle]

relevel the floor first. when using leveler make sure u read the instructions as amount of water is critical as to little and it wont flow to much and you could get a crust or cracking . prime the floor with a sutable primer or sbr first. once level using a 8mm tile trowel you can start laying your tiles you could use a tile leveling system this will assist in avoiding lipping sugest u use a flexi tile adhesive and slow set as rapid may go off to quick .as the floor is quite small you could dry lay and cut first good look

 

[Mikeclem]

cheers for the reply, when preparing the leveler the mix ratio was adhered to precisely, I am honestly that OCD it was measured perfectly, it's like the slab has a bowl affect in that the raised areas are flat so the compound set ok on these areas and followed the slab contours towards the center, the finish is ok, there is no cracking or peeling, feels hard as nails to touch, Norcros prime bond was applied to the floor prior to the Pro50 SLC. So it's ok to put SLC down on top of SLC? Thanks for your help.

 

[Just Rizzle]

if your prep work is right the job is easy. if you need to level put some hight markers on the slab when the leveler reaches the top u have it right