Self levelling concrete...? I don't think so!

[skylined_gtr]

Hi All

I am really getting frustrated with this so hoping one of you guys might have a good tip on how to do this.

I have concrete subfloors, I have chased a line which is 3.5cm wide x 360cm long x 6cm in depth. Using the chaser and SDS hammer to punch out the concrete has left me with a slightly uneven surface inside the chased line. (in case you're wondering, I am sinking alluminium track into the line I have chased to mount some sliding doors on)

I am using a B&Q self levelling floor compound mixed to the correct consistency and pouring it into the chased line, but once it dries I end up breaking it all out again as it hasn't levelled!!

I have done this twice now and on both occasions it's not levelling out, leaving an uneven surface which goes up and down. I have made sure that when I am pouring it in I am swishing it from one side of the line to the other to ensure it is as even as possibe. I look along the freshly poured compound and it looks dead even but when it dries it's not.

Anyone have any ideas? Picture below please click on the image to bring up a larger version.

Line chased in floor

• skylined_gtr
• 10 Dec 2008
• 1

I'm going to get on with chipping the 2nd try of the compound out while one of you answers

 

[regsmyth]

I take it your floor isn't flat and even, so you want the surface of the compound to give a flat even surface for you to fix the aly into?
I assume you don't want the surface flush with the existing floor.
If you mix up the compound to a very stiff consistency, you should be able to use a long straight sharp edge (like a 1m ruler) to scrape the surface back as it starts to cure. Alternatively, fit the track using plastic/metal packers underneath, chip out the groove in a few places and pour a much more liquid mix under the track.
I think "self levelling" doesn't quite mean what you think it does. To me it means that the surface dimples and trowel marks all disappear as the stuff settles, but if you don't put it in exactly level, it won't do it for you.

 

[noseall]

why on earth don't you mix some strong mortar, thoroughly damp the concrete down, apply the mortar to the trench then push the channel into the wet mortar.

tap it level, remove the excess mortar, et voila!.

 

[skylined_gtr]

Hmm ok thats a good idea only problem is the track is in 2 sections and I'm not sure I'm that good at getting it dead level with mortar, that's why I was hoping to use the self levelling gear.

I am getting a little suspicious of the self levelling stuff I bought, I could feel the water at the top and the sedement at the bottom after I had poured it despite mixing it thoroughly.

 

[noseall]

use a straight edge to bridge the two sections and tap level.

forget floor levelling compound.

 

[Thermo]

go with noseall, self levelling compound is like trying to work with cake icing!

 

[skylined_gtr]

Ok thanks for the advice guys, I'll give it a shot! Will post back and let you know how I get on! Thanks very much for the pointers.

 

[skylined_gtr]

That seems to have worked... thanks very much! Only one downside is that the mortar is obviously thicker than the self levelling concrete and so I have to change my design slightly but thats better than having a wonky track!

Thanks again.