very unlevel concrete subfloor with gradual slope

[mitch40]

I am planning on placing travertene flooring 24"X24" on a sloped concrete sub-floor. The floor extends downward approximately 3-4 inches from the center of the room out to the outside wall of the house. What is the best way to accomplish a more even sub floor so I can apply the travertene? Please help!!!!!

 

[alfiembra]

It's a bit difficult to picture a slope of this amount within a room, has there been settlement or has the sub floor just been badly laid? Or am I not understanding the question here, are you inside or outside the building?

But assuming it's inside you could build up the slope with a screed to get the floor reasonably level. At the thicker areas you could use a simple 3:1 sand:cement mix, where you meet the high point break out the existing concrete to a depth of about an inch so that you you don't go too thin with your new screed which would then crack.

HTH

Alan

 

[mitch40]

The floor is inside the house. The area I'm describing is, you walk through the front door and you see a single story floor plan with a living room to your right and a dining room straight ahead. The center of the room is seperating the two rooms approximately. The greater part of the slope, falls toward the outside wall of the front of the house in the living room. Pardon my ignorance but what is a screed? What type of cement should I lay ontop of the concrete subfloor. Quick set? Or should I lay a wood subfloor built up to accomodate the slope difference. It was a bad initial lay of concrete. No cracks noted.

 

[alfiembra]

OK we seem to have a bit of difference in terminology.

A screed in the UK is a layer of fine concrete used to provide a smooth surface prior to floor finish, generally these are about 2 - 3 inches thick you maybe know it as mud in the US. It is basically concrete without the aggregate. Quick-set doesn't sound like the correct type of concrete to use either, with virtually all types of concrete pours you don't want it setting too quickly especially thin screeds as they will crack we use OPC here (ordinary portland cement) so whatever the US equivalent is to that would be fine.

I'm interested to know what your existing floor finish is because if as you say there is a 3-4 inch fall across the slab at present how is the floor levelled off?

Remember also when you lay your new floor it will be laid on grout so make sure you have all your levels worked out so that the new floor is flush where it meets the existing at doorways.

Alan