I've got some Weber SLC to do this with.

Having tried to contact Weber technical today to find out about the best way to approach this and failed, could anyone please suggest and idiot's proof guide to this job?

I am fairly inexperienced with SLC as many of my floor tiling jobs have oddly enough meant me tiling onto good floors or new screeds that I have laid.

From looking on here the practise seems to be to mix, pour and spread out using a flat bed trowel, then allow it to find its own level. I've got about 9 m squared to do. My concern is that the first mixes start to go off before the last mixes get poured.

I probably need to build up about 8mm in floor height overall. I guess I'll be doing this in stages, say 3mm at a time, let it go off then another 3mm.

Would that be right?

Nope do it in one hit.
152-153 weber.niv floor.pdf

It's got a 45 minute working life, I don't think I can do it that quickly Neale. There's 9 bags of the stuff.

Now I can feel myself starting to panic!

Do I just pour it in the centre or do I work my way from the edges pouring towards the centre

Just start from a corner and work your way out. I did 18 recently, didnt take long.

This may sound like a really stupid question but what exactly is the process here Neale?

Do you just pour it and hope for the best, or do you have to help it?

And how do you ensure that you get the 8mm all in one go without.....

a) ending up in one lump

b) having to walk in it once it's down but before it's fully dried?

1st Prime the floor.
2nd get all your water and bags ready.
3rd Big buckets to mix with
4th Mix a bag at a time
5th pour it all out and repeat 4 and
You will need to help it slightly and it may help you if you place a few bits of old tile around the floor so you can tell when you are meeting the required heights. these will need to be placed and levelled of course.
levelling isnt that hard at all and dont forget that you dont need a perfect surface unless you are laying soft floooring.

One idea that did occur to me is to mark the required height on the walls. Then I can get an idea as to how close I am to it. The concrete floor is fairly even, and had it not been for the floor height, I may well have considered tiling straight onto it.

Having said that, with the fight I'm having getting tiles dead level at the moment I was hoping that the SLC would make it easier.

One assumes that if I fix the tiles in place to level up to these can stay put after the SLC is down?

Don't panic about it Hugo, it's easier than it seems. A screed is fluid but probably not as fluid as you're thinking. Follow Sir Ramic's instructions and you'll be fine. It actually takes longer to set up and clean up than it takes to do the job.

The pieces of tile need only be 10mm square. They are only there to give you something to work too and can stay there when levelled . As you pour you will see the leveller reach the top of the tiles and then you stop pouring.

I gauge my depth by fixing screws to the concrete every 6 ft or so and use a level over the top of them ( when dry you just unscrew them). I also use self adhesive draught excluder foam round the open edges like doorways or under kitchen units where I don't want it to go and it maintains level right up to the edge. Bear in mind though I usually do it for Karndean/Amtico so I need it much flatter than is required for tiling.

hiya mate , poured 7 bags of ultra on 30m2 today in 2& half hours , just needed the top few mm spreading about ,which i use a 1metre ali rule[with a homemade handle]

Thanks for all the replies.

I have one burning question. When you are smoothing out the last few mm how on earth do you achieve this without stepping in it? One assumes you kind of commit yourself to being happy with the areas you pour first before they become out of reach?

my [trowel] is 1 metre long at arms length,simples!!!!!

You start at one end and work towards the door.

Cornish Crofter - Like u I was a SLC novice until fairly recently. Last week I SLC'd 16 sq m in an hour, 3mm depth over UFH. Some things to consider:

- Most SLC's work best at 4 litres water per 20kg bag. However do consider that some special types do need less water.
- Make sure the central heatiung has been off for several hours and stays off until slc has set. If you dont the slc will get hairline cracks.
- Before starting get bucket loads of water ready at your mixing area - if you dont have an electric plaster/adhesive mixer - now is the time to buy one.
- Make sure your mixing bucket can mix and carry 20kg of slc and 4 litres of water - it is quite heavy and the bucket needs to handle the weight.
- A plastic spiked roller really helps, but is not essential - a basic plasterers trowel will do a very good professional finish - J trowel (walking stick strokes) the slc like u would multi-finish plaster.
- Plan how u will work - start at one corner and zig-zig back to your finish point (usually the door)
- Dont play with the mix. Pour a bit. Trowel it. Pour some more. Trowel it. Trowel to your depth - a well mixed slc is a piece of piece to work.
- Dont stop for a fag break. Keep goin until you finish.
- You have about 20 minutes with most mixes before they start to distort if you trowel around them. Rermember that as you move across the room. The best finishes come from steadily moving back and forth across the room and adding new slc to already laid slc that is less than 20 mins old.
- Because a good mix of slc can be easily troweled that last few feet of slc can be done from the exit doorway.
- If you dont have the confidence - buy urself a couple of bags, and practice slc in ur garage - it can be easily chipped up after practice.

And finally search this forum for threads on slc's - a lot of good info on here - some quite old. Reading it will boost ur confidence in doing the job.

Finally remember - Tiling is harder than laying a good base of slc.

This is the way I level slc runners in to laser then flood

I'm sure you don't need a bucket to remind you which one to mix in Phil

Originally Posted by andy8758

Cornish Crofter - Like u I was a SLC novice until fairly recently. Last week I SLC'd 16 sq m in an hour, 3mm depth over UFH. Some things to consider:

- Most SLC's work best at 4 litres water per 20kg bag. However do consider that some special types do need less water.
- Make sure the central heatiung has been off for several hours and stays off until slc has set. If you dont the slc will get hairline cracks.
- Before starting get bucket loads of water ready at your mixing area - if you dont have an electric plaster/adhesive mixer - now is the time to buy one.
- Make sure your mixing bucket can mix and carry 20kg of slc and 4 litres of water - it is quite heavy and the bucket needs to handle the weight.
- A plastic spiked roller really helps, but is not essential - a basic plasterers trowel will do a very good professional finish - J trowel (walking stick strokes) the slc like u would multi-finish plaster.
- Plan how u will work - start at one corner and zig-zig back to your finish point (usually the door)
- Dont play with the mix. Pour a bit. Trowel it. Pour some more. Trowel it. Trowel to your depth - a well mixed slc is a piece of piece to work.
- Dont stop for a fag break. Keep goin until you finish.
- You have about 20 minutes with most mixes before they start to distort if you trowel around them. Rermember that as you move across the room. The best finishes come from steadily moving back and forth across the room and adding new slc to already laid slc that is less than 20 mins old.
- Because a good mix of slc can be easily troweled that last few feet of slc can be done from the exit doorway.
- If you dont have the confidence - buy urself a couple of bags, and practice slc in ur garage - it can be easily chipped up after practice.

And finally search this forum for threads on slc's - a lot of good info on here - some quite old. Reading it will boost ur confidence in doing the job.

Finally remember - Tiling is harder than laying a good base of slc.

well said!!

[QUOTE=whitebeam;477216]I'm sure you don't need a bucket to remind you which one to mix in Phil[/QUOT


When you get to my age Beam, you can't be to careful

now i know where you got your name ' half a mill phil'

ed

Well

I am soooooo annoyed

Despite all you wise words, and that of Weber when I finally got in touch with them, I may as well ahve stayed in bed all day because the application of SLC was a disaster

I mixed my first mix at 5.25L of water to 25kg of powder as instructed by the bag, let it sit for 2 minutes whilst I replenished the water and got another bag ready. I then poured it.

It was soooo runny I thought it wouldn't stop. There was no hope of trowling it whatsoever! I had just spent about an hour and a half setting 30 plus screws into the concrete base and levelling them all to a datum. I was trying to got 10mm average and these were set to give me that.

I then phoned Weber to ask them why it was so runny. They suggested using a little less water. So I mixed further mixes with only 5 litres.

I then did my best to try to level it. I was using a 6ft derby to smooth it over the screw heads to give me a level. Bearing in mind these are all set to within fractions of a mm to each other. I was smoothing it over in both directions.

Anyway, even after working out the volume I needed and having the tile shop verify my calcs. They are correct. I actually ran out. I have an area that is not covered at all and the rest of it simply slopes down to this corner. Even the areas that look level are out. The worst is 3mm.

I can't understand it. God I feel so fustrated. I did everything by the book and I've still got the bloody alps in my conservatory.

What did I do wrong?!

What was you laying onto, was the floor sucking the moisture out to quick

Concrete floor. It wasn't setting too quick. I definitely had the 20 min working time and more.

I use ultra 2 and would prime the floor first, just the plastering side of me.

I did prime the floor.

The sad tale is on the other thread.