Best self leveling overlay for a rough "lecamix" subfloor?

by lisa
(italy)

Hello,

I live in Italy and am desperate for advice on finishing a concrete floor in our attic(3rd floor). We pulled out the old wood flooring and put in a "sub floor" using "lecamix". It is very uneven, to level out the floor, some areas would need 1 inch and other areas just need around 1/16 of an inch or less. We would like to have as a finished floor, acid stained concrete or colored concrete. It seems as though there are 3 options to finish it, but I can't find anyone here to help me decide what is best.

1) Should we level out the pad with a regular concrete mix and "power trowel" it smooth? (I don't think we have enough thickness is some areas to machine polish)

2) Better to level it with concrete and then a thin micro topping?

3) Level it out completely with micro topping?

My concern is what will bond the best to the lecamix? It is "rough" with no stains or sealer.

I have read a lot on acid staining and understand how to do it, but have read so many conflicting opinions on whether regular trowel finished cement or micro topping is best. Here in Italy, this is so uncommon that no one seems to know or understand anything about it. The few big firms that do acid staining here will not sell their products to "DIYers" which is why we are considering just coloring the cement - no acid can be shipped from the states! (they also will not share any info)

The overlay that I can find here is Mapei "ultratop". I've read good things about it, but it is quite expensive here!! I wanted to finish the terrace in the same way, can we use "ultratop" outside?

Last question, if we "color" the concrete during the mix, when it is troweled, can we still get some uneven tones or "mottling" or will it just look like one solid color? I know it will not be like acid staining, but is there some technique for getting a bit of texture?

Sorry for the "epic" post, but it is so difficult to get good information here on this topic.

Thank you so much for any advice - your website is great!
Lisa

A. Pouring regular concrete on the third floor would add a tremendous amount of weight to that floor. The concrete would have to be at least 1.5 inches thick on the thinner side which means it would be about 2.5 inches thick on the other side. You would wise to hire a structural engineer to check the sub-floor if you go this route.

I would go with the Mapai Ultratop. I have used this product and like it. It is quite easy to install, it self levels, you can stain it or add color to it. Much less weight added to the existing floor also. It can be used outside.

After you price the cost of the concrete, a pump truck to get it to the third floor, and the labor to place and finish the concrete, I think it will be close or more than the Ultratop material.