self levelling compound

[CJ CERAMICS]

right guys,
i know that this will probably make me sound like an idiot....but here go's.
due to having a friend who worked for a flooring company ie screeds levelling etc, i have always been able to sub any floors that needed levelling out to him (materials borrowed... and one days labour charge). so it always made financial and economic sense to have him do it. he would do the floor and i could be somewhere else tiling and then come back to the floor. sadley he has now moved to australia for a better life. so basically i have never levelled a floor. how difficult is it to do ( i have studied videos over the last couple of days but they make it look so easy). i have a 22sqm kitchen to tile but the floor in my opinion needs levelling as the extended floor slopes away by about 5mm.
questions.
1) how many bags would i need for 22sqm.
2) what prep would i need to ensure bonding(floor is concrete)
3) what product is best to use was looking at ardex k15.

if any one can help i would be very grateful.

 

[Rob Z]

Hi CJ

We have used a lot of SLC, so maybe this will help...

We thoroughly clean concrete slabs with Aqua Mix Tile and Grout cleaner if they are dirty. If the slab has cut back adhesive on it, paint, or any other crud, we bush hammer it down to raw concrete.

On certain slabs, we just skim the slab with a qood modified thinset and let it dry before proceeding.

Prime the slab according the the instructions...we always put on one extra coat of primer more than what seems to be enough, just to be sure. Primers need to be agitated into the surface of the slab with a bristle brush, and not just rolled on.

We install sill-seal around the perimeter of the room so that the SLC pour is separated from the house with an expansion joint.

It's hard to say how many bags you need for that floor without knowing the average depth that you need to pour.

I would recommend that you have one person with you to do that pour...it's a lot of area and you will go through some material.

When you mix the SLC and pour it in place, you need to maintain a "wet edge". The edge of the SLC will start to skin over fairly quickly, so the next batch needs to get in place quickly and flow into the first so they will bond together without a lumpy ridge between the pours. You can use a rake or a trowel to break up the surface tension on the edge of the previous pour to help the two flow together.

We measure out all the water for all the bags we are going to pour, and have it ready in advance. Once we start mixing and pouring, we don't stop for anything. The brand I use (Laticrete #86) can sit mixed in the bucket for up to 30 minutes, so we can mix a lot of buckets and have them all ready to pour at once.

In my opinion, SLC is equal parts prep work, skill of application , and witchcraft.


This is a big area to do for your first time. It would be great if one of the guys from the forums that lives in your area could help you with this first one.

 

[Rob Z]

CJ

also...it's important to make sure the heat is off in the slab (if any), the AC is off, there is no air movement from fans, etc, and the windows are covered if strong sunlight is coming through them and shining on the floor.

And...corral any pets. Yes, my customer's cat :mad2: got into the SLC one time and tracked it through the house.

 

[CJ CERAMICS]

thanks rob i do agree that this may be a step too far for my first time and would happily outsource if poss. the floor itself is not overly unlevel but the customers have spent alot of money on their kitchen itself and are buying expensive tiles and i think that to have the best possible finish you need the best possible surface to tile on.
the only problem is making the customer aware of this and the cost of it without scaring them off.
chris

 

[smurf21]

i would be looking at about 8 20kg bags of slc for an average 3mm bed 2 men one mixing one pouring and rolling, get yourself a good spiked roller should take two men about 1 1/2 hours if that to get it down and rolled

 

[faithhealer]

CJ


And...corral any pets. Yes, my customer's cat :mad2: got into the SLC one time and tracked it through the house.

Went to have a look at the base for my dads new conservatory at the weekend and sure enough, paw prints running through it!

 

[hillhead]

Make sure you have a spiked roller to expell the air too !! Dave at TT sell damn good ones.I bought the 500mm one from him.

 

[Time's Ran Out]

CJ - I reckon Rob Z put a lot of effort into that reply!

I 'am not sure if 22 sq metres is how he read it or if there is an American equivalent but I get most of the jist.
Ardex make some good slc. but I'am using Mapei Fibreplan just now and you get good coverage : 22sq mts - approx 4/5 bags at 4/5mm
Mix it as it says on the bag 6.5litres water and it will flow.
I use a 15 inch flat trowell and it works a treat.
Make sure your floor is dust free before you start!

John.

 

[CJ CERAMICS]

cheers john
yes rob did put a lot of effort into his reply
and very thorough it is aswell i have pasted it to my saved data in preperation for a trail run as my garage floor is used as a testing pad instead of a garage.
what he has written should give me a good knowledge about the prep and installation.
mapei fibreplan seems a good way to go
i will price up at my suppliers this week.
thanks
chris

 

[Rob Z]

Hi guys, I'm still getting the hang of this metric thing but I think I calculated one time that a sq meter is about 10.5 sq feet, so CJ's floor for me is about ~230 SQ FT.

Chris, I went to look at Harry Dunbar's Canadian site, but I couldn't find my photos I had of an SLC pour we did a long time ago. Harry had asked me for pictures so he could do a link of various types of tile work. I'll see if I can find some other photos to post for you.

That two hours of work that Smurf mentioned is fast and furious. When you are finished you'll want to go get a beer and take off the rest of the day.

 

[Rob Z]

CJ, are you going to give a shot and do the work yourself?