C
cornish_crofter
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
OK this is what I did.
1) Swept floor.
2) Put a level going from the centre of the room out to corners and sides to give me an idea as to where the high spots were.
3) Set a screw in the centre. Judging by where how the level behaved I set this at app 10mm. I knew it would be less in some areas and more in others
4) Drilled, plugged and set screws around the floor app 2 feet apart in a rough grid pattern. Each screw was adjusted to be level with the centre screw or datum screw. I also checked the screws with each other to make sure the heights were consistent. By the time I'd finished I had about 30 odd screws all at the same height as one another. If I couldn't reach a screw with the 6ft level I would take the height of other screws and cross check them. A HELL of a lot of time went into this.
5) Cleaned the floor again, only this time more thoroughly.
6) I then checked again for level screws. As for high spots on the floor, the height of the screws illustrated the high points. So I could see where more SLC would be needed. Also I could see where high spots were and knew that when I poured slc there it would go further so I had to be ready.
7) Primed about 1/2 the floor. I did this so that the SLC would land on it whilst it was still tacky, but not too wet.
8) Mixed the first bag of SLC according to the instructions. As I was working alone I couldn't pour and mix at the same time, so I added about a quarter of the bag at a time. I added 5.25L measured out of clean water. It was at this point I noticed that it was quite runny.
9) equipped with a 6ft derby, plasterers trowel and levels I poured the first mix. Thinking I could settle it at 10mm depth using the screws to guage the depth and the derby to level it I poured it across the far end of the room. It was at this point I found out that this wasn't the case.
10) Phoned Weber and spoke to their product manager and explained that keeping it to 10mm thick was not possible as it was too runny. He advised me to use less water, maybe 4.75l or 5l in the next mix.
11) I then mixed up the 2nd with less water, about 4.75L. I had taken some of the water out of the bucket before mixing. In an effort to get the depth I then poured it on top of the first mix. I suspect this was a mistake. Although I did make an effort to level it out I must have paid too little attention to a corner.
12). As I worked along I mixed up and poured the floor in strips across the width of the room. I varied the water between 5 and 5.25L in an effort to get a feel for the mix. Again I used the derby and the plasterers trowel to level and move it along. I did try to use the derby in the other direction (end away from me as opposed to holing it parallel to the edge of the mix. Where it was slumping too much towards the front I was pushing it back to cover the screws and draw it forwards again. I suspect this created a slight ridge in one area, but I managed to scrape most of it away after a few hours.
13) As I got perpendicular to the door I started working with my back to the door and carried on the same vein. At this area the concrete slab rises a little so I started to mix 5.25L mixes and work back.
14) I only managed to get a couple of mixes in this direction when I ran out. I was hoping that I would be able to work my way out of the door adding the right amount of SLC to sit inside the floor, levelling out as I go, and it would be stopped by the door threashold and walls etc and settle in place.
I didn't spend a huge amount of time trying to get it dead level but I didn't pour and hope for the best either.
Maybe the problem lies in that method.