I am about to go and dig up my SLC - rebag it and return it to Weber!

[doug boardley]

strangely enough I'm using Weber slc today, (freebies), I'll let you know what I think. Like Mark, I normally use Ultra.

 

[Andy Allen]

i use webber all the time .........and imo its spot on, good price, 25kg bag, 30mm depth.

when you mix it use your own judgement, its needs to be like cream, and not like pee.

 

[cornish_crofter]

i use webber all the time .........and imo its spot on, good price, 25kg bag, 30mm depth.

when you mix it use your own judgement, its needs to be like cream, and not like pee.

Did you batten the floor up and pour and level small areas one at a time? That is probably what I would do if I had my time again.

I have no idea how you're supposed to lay a 10mm screed without battening it when you mix it according to their instructions. It basically poured like single/double cream but then spread out very rapidly, I wouldn't say it was completely like water but it spread quite thin and I found it impossible to get the 10mm. It just ran away too much. Even pusing it back was useless as it just ran forward again.

I think the only way to achieve 10mm build up without battening would be to remove a litre or so of water when mixing it. I suppose it's easy to judge it when you've worked with it loads of times.

I then poured the next mix straight on top, and that has not helped by creating high spots. Having taken a proper look today I found that the difference in levels is actually up to 6mm in 6 feet. Ironically I would have been better off tiling on the concrete slab as that also varies by 6mm or so, and I would have saved myself a small fortune.

Oddly enough, putting 5L of water did make a difference. For the last couple of bags I went back to putting 5.25L as requested in the instructions. That was because I was dealing with a high point in the floor and I felt it would enable it to flow a bit easier over this area - I was needing to lay it about 5 mm or so. I found that the mix was not as watery as the fist bag, despite putting the same amount of water in - Bizarr.

Essentially I suspect that as you say, it may be possible to use less water and have a stiffer mix, just like mortar etc. However this wasn't effectively communicated to me by Weber. And as it may as well be the first time I've ever used this stuff I simply trusted that the information I was getting was accurate, in terms of coverage, consistency and the amount of water to be added.

 

[Andy Allen]

are you trying to make the floor level or flat?

if your floor isn't level then slc will simply run to the lowest point, the more slc you put down, the more it will fill the lowest points and make the floor level, but this will depend on the size of the floor and how much out of level it is

 

[cornish_crofter]

are you trying to make the floor level or flat?

if your floor isn't level then slc will simply run to the lowest point, the more slc you put down, the more it will fill the lowest points and make the floor level, but this will depend on the size of the floor and how much out of level it is

I am trying to make the floor level. I want to make the tiling as easy as possible and I want them to be flat.

The floor is around 3.5m x 2.6m.

The slab was about 5 to 6mm out of level between the high and low spots. I know this because I set about 30 odd screws in the floor and levelled them all up. You can tell how the levels change.

I am thinking of priming what is there then applying more SLC starting in the corner to give me a minimum 3mm of thickness at the highest spot and thus giving me about 13mm where there is currently no SLC. I guess I would just have to use a flooring trowel or similar to move it around gently to help it find its own level.

That sounds very easy but I have an odd feeling I'm going to screw it up again.

 

[dilz000]

Have u not got one of those spiked rollers that you roll through it to get any air bubbles out and level it out? There on tiletrader!!

 

[chrisroe]

you need a screed rake and a spikey roller

 

[TrumpersUnited]

I use a spatula like photo attached.

i always base coverage on 3m2 a bag at 5mm or 5m2 at 3mm.

I must admit i use weber floor flex loads and can't fault the stuff.

If you spend time preparing the floor and use a spike roller or spatula you'll never have a problem.

Hope you get it sorted out ok.

 

[cornish_crofter]

All these people telling me they've got no issue with the product makes me think I'm just being kak handed at the moment, which isn't helping a huge amount. Please be aware that I have no issue with the product itself - it's the misinformation that is a problem.

I still can't reconcile how you would manage to build up 10mm when mixed according to the instructions though.

I am coming to the conclusion that the product is OK, it just won't do what they said it would when you mix it according to the instructions. As I've said before, I've hardly ever used this stuff before. The last time was 4 years ago half heartidly. Using it for the first time you have to put your faith in other people. when the manufacturers tell you to mix it with 5.25L of water per bag and then tells you you can lay 10mm in one go you tend to believe them, unless you've worked with it and know that not to be the case.

I see you've used packers stuck together to give you your height. I did a similar thing with screws into the concrete. The idea was to keep the screws just visible.

I like your idea of a spatula on a pole - I think I'll adopt the same. It gives you good reach. I think I may see if I can get a spiked roller as well and a cheap garden rake.

I think if I had my time again I would have done it in 2 hits or battened it out and done it in sections. It's too late for the battens now. I just want to get it level and flat. To that end I think I'll add the max amount of water I can to make the slc flow better.

The coverage of 3m squared at 5mm would equate to 1.5m squared at 10mm. Being that I worked out the averaga height at 10mm 7 bags should have definitely done it. I can't think why it didn't. Although I think I may have gone 3mm over in one corner thanks to trying to build it up and over doing it, but that shouldn't have made that much of a difference.

 

[White Room]

The spatula is similar to what I use but mine has a 600mm blade

 

[Aston]

did you check the floor prior to laying the slc??

did you put a straight edge down to see where there was high spotswhere?

or do you just pour and hope for the best......lets know how you went about establishing things

 

[newlineuk]

Do weber have quartz sand aggregate to mix with their slc?

 

[White Room]

I've used course sharp sand or grano dust to bulk the slc

 

[TrumpersUnited]

not as far as i'm aware. it's a fibre reinforced leveller can go up to 50mm in one hit.

 

[newlineuk]

not as far as i'm aware. it's a fibre reinforced leveller can go up to 50mm in one hit.

That's the answer I was looking for.
But to get to 50mm thick you would need to batten out and that I think is where cornish_crofter has come unstuck.
It says on the bag what thickness it will go to but dosn't say how, to get to it.