How exactly do you use self levelling compound?

[Teachmesomethingnew]

I know it is a thick question but I am clearly too thick to be able to do this simple job properly.

I am in the process of laying a new wooden floor throughout the ground floor of my house. In the summer I did the hallway, the area by the front door was very unlevel and dipped downwards towards the door. I used Wickes Self levelling latex stuff and followed the instructions to the letter. The result was more level but still not spot on. It took 2 coats to get the level right on only a small space. I mixed the stuff correctly, then trowelled it over the necessary area.

In the near future I am going to have to do the lounge, it has a similar issue, generally uneven floor, bit like waves! How do you get a good flat result with self levelling compound i.i.

What should the ideal mix look like, what do you do to make it self level properly?

Thanks

Andy

 

[Softus]

When mixed it normally looks like grey pithy syrup.

Pour it in the low points first.

Don't buy a Wickes product - they're generally not the best quality. Go to a local specialist tiling centre and buy what they recommend.

 

[Teachmesomethingnew]

I spent a great deal of time on the internet trying to get an answer to this question, so, here is a compilation of all the info. I have gleaned.

Latex Self Levelling compound comes in two types, first the powder and latex mix type where you buy the powder cement product and a bottle/barrel of latex liquid to mix with it, or the second which is an all in one powder product which can be mixed with water.

I used the second type, the all in one, mix with water type.

I talked to several local tiling shops and 2 local tilers, they all said that the name on the bag does not make a lot of difference, the mix and the prep is the important bit.

To prepare a floor, first know the limitation of the product. I was levelling an uneven concrete floor in a 20 year old house. The floor was stable, and extremely dry. I hoovered the floor, then rubbed off any high points, or very noticable lumps in the existing concrete with an angle grinder. Then hoovered again. I then painted a mix of 1 part PVA glue to 2 parts water on to the floor as the glue directed for sealing dusty or porous surfaces.

Next I took a long level and found the highest point in the room. I then marked the floor with a felt tip pen to remind my self where the deepest of the depressions were.

I then mixed my self levelling compound as per the instructions, thought it was a bit too stiff and added a bit more water until I got to a syrupy, runny texture. I then spread a little self levelling compound on the floor with a 12" plasterers trowel anywhere the compound would be going. This would release surface tension on the floor when I made up the level.

Next I poured the self levelling compound onto the floor heaviest on the deepest points. I used a level as a long scraper working across the floor, the self levelling compound began to dry rapidly, so I worked as fast as I could. I filled the main voids and got the minor depressions level with cost number one.

I then left it 24 hours to harden. Next day, repeated the same procedure as before, again, using a level to form the self levelling compound, focusing on the slight depressions, smoothing a lot with my plasterers trowel.

I left the compound for about 30 minutes, and went to check it. In one or two places, I had over filled and created a ridge or a lump, so I used the edge of my plasterers trowel to gently scrap off the excess compound.

I then left it to harden. On checking the level is pretty much spot on, they are still very slight undulations, of no more than half a mm across a 1.5 metre level. The floor has hardened nicely.

A couple of quick points -

1. Self levelling compound does not self level, it MUST be guided into place using a trowel.

2. The brand is not a great deal breaker if you are a DIY at home person.

3. The instructions on the packet are not necessarily perfect, go by feel for the correct consistency, the description I found accurate was cold, runny porridge, or as my mate said, grey runny snot!

4. This is an amateur set of instructions based on my personal experience of using Wickes own brand latex self levelling compound, I found it okay to use, mainly as I couldn't find anywhere else that sold this stuff!

Thanks for reading,

Andy

 

[mattysupra]

if your happy with the result then fair play for having ago, im a bit late answering this as you already done it now but i will write a post for others to see.

 

[cyberdyne]

I spent a great deal of time on the internet trying to get an answer to this question, so, here is a compilation of all the info. I have gleaned.

..//snip//..

Thanks for reading,

Andy

Just had to say thanks for taking the time to write this, it helped a lot.
Cheers Andy.

 

[andfinally]

Thanks for the tips Andy, they were useful! There's no much info out there about levelling selected parts of a floor. Just adding some bits about my experience as a total amateur with Ezy Pzy Levelling Compound from Homebase, also a latex compound you mix with water.

A 10kg batch doesn't go far – I did two applications using the powder from half a 5kg bag each time, and it was only enough for some smallish patches I wanted to fix. The consistency is a bit more glutinous and rubbery than plaster – it hangs together and the trowel doesn't smooth it out so easily as plaster, though it you can feather it out towards the edges with the edge of the trowel. The first batch started to dry quicky, so I added 10% more water to the second batch and that made it easier to spread... I might add even more next time.

I think this kind of stuff can be fine if you just want to level out a selected patch of a floor and you don't want to go the whole hog with self-levelling compound.

I'm happy with one room I did, but in the other, I ran into a problem where the floor was level in one direction, but out of level in the perpendicular direction. I think for that sort of bump, a full application of self-levelling compound may be the best fix. Having practiced on a small scale, I'm now less nervous about the idea of doing the whole floor. I'm going to see how well my LVT holds up on this subfloor – it tolerates up to 5mm variation of height in every 3m – and if I have to take it all up again later, I'll look at doing it properly.