self levelling question, help requested

[Bartlett]

Hi, wonder if you can help me out here? I am going to tile a shower room floor with 300mm ceramic tiles. The existing tiles have come up okay and most of the previous adhesive, but the concrete floor is now a little uneven. I have been advised that maybe a self-levelling compound would be good but I wonder if it is really necessary? How uneven does the floor need to be to justify this?
If I decide not to go down this route what can I use to fill the odd hole etc? Also, there is a drain cover (it's an old garage floor) in place which was previously tiled and I will tile onto this again, so I do not really want to alter the height of the floor.
The screed floor is sound but a little dusty, so does this need sealing? If so, what should I use? I quite like BAL products, local and easy to obtain for me.
Lots of questions I know, sorry! Looking forward to any help that you can offer?

 

[White Room]

I would selflevel will make the job a lot easier

 

[doug boardley]

is it the adhesive that is left on the concrete floor that is making it uneven, if so can you not remove it with an sds hammer drill?

 

[Bartlett]

The old tiles and the adhesive have been removed but what is left is a slightly dusty but sound cement floor. I laid my long spirit level on it and it is pretty flat, with max variances in some places of maybe 3 to 4mm over 1.5 metres but generally not too bad. There are a few gouges and small holes which are maybe 15mm diameter? and 6 or 7mm deep but not many.
I have been advised elsewhere that it may be okay to prime it (with BAL APD) and then lay the floor. Or to use acrylic bonding (never used this before, can anyone suggest a product?)
Wonder what you think?

 

[White Room]

Sbr thinned down 3-1

 

[DHTiling]

Moved to prep forum.

 

[brian c]

if its only 4 to 5mm then back butter the tiles where the holes are.Prime floor first though.

 

[Daz]

Try and get a bag of Ardex A45 rapid set cement. Mix it with warm water and it will fill your holes a treat . Work quick though, as it will be workable for 15mins and set rock hard in no time!

No need to self level that floor, IMO, just patch the holes and back skim / butter to get 100% adhesive coverage.

Good luck.

Daz

 

[Alpha Omega]

Just use SLF on the bad bits,
If you can run a trowl over it without it catching, you will be fine

:8:

 

[Alpha Omega]

"the concrete floor is now a little uneven. "

As suggested SDS chisel to remove all adhesive

"I have been advised that maybe a self-levelling compound would be good"

From what you say doesn't seem to justify

"The screed floor is sound but a little dusty, so does this need sealing? If so, what should I use? I quite like BAL products, local and easy to obtain for me."

Yes - use Bal APD diluted 1 - 1

Lots of questions I know, sorry! Looking forward to any help that you can offer?

:8::8:

 

[Bartlett]

Thanks everyone, plenty of good advice coming in. So, for the novice in me, can you please let me know.....
What is SBR and what is SLF?:huh2:
Sorry, my tiling is coming on pretty well but I have some work to do on 'tiler-talk'!!!

 

[White Room]

The ultimate bonding agent in which a carboxylated styrene - butadiene copolymer latex (SBR) replaces conventional P.V.A.’s due to its excellent durability, reduced shrinkage and its increased flexibility. SBR Bonding Agent allows internal and external renders to flex. Unlike P.V.A. it will not re-emulsify in damp conditions

 

[Bartlett]

Okay, I have been back to look at the job in hand and customer has now removed all the adhesive from the floor. It looks much worse than I remembered so I think it definitely needs a self levelling compound.
Not done this before but I watched a quick 1 metre SLC demo recently. I am assuming I still need to seal or prime the existing concrete floor and then self level. This is not a rush job so I can allow it to dry for a day or two if necessary before I tile. What would be good products to use? Any tips you can give me on the process? Thanks.

 

[White Room]

I would seal, I use mapei eco and find it extremly easy, spiked rollers are a good product to help wirh the smoothing out

 

[doug boardley]

Thanks everyone, plenty of good advice coming in. So, for the novice in me, can you please let me know.....
What is SBR and what is SLF?:huh2:
Sorry, my tiling is coming on pretty well but I have some work to do on 'tiler-talk'!!!

Stiff Little Fingers? I think Alpha meant slc "self levelling compound"