level concrete floor

I enclosed a porch that had a concrete floor and now want to lay tile. The problem is that the slope of the floor is not consistent. It comes off the interior wall at a gradual slope for about 5 feet and then dives down at a steeper grade to the outside wall.
I would like to extend the gradual slope to the outside wall. This is a difference of about 7/8" in grade.
So any self leveling mix or mortar bed would have to be 7/8" thick by the wall and then taper down to a troweled feather edge about 7 feet away. I need to do this over an 18 foot long area.
I have considered using levelquick but have no experience with it and hesitate to get involved with a quick setting product over such a large area.
Can a cement/sand/additive mix be used in this application. That way I would have time to mix it up, screed if off, and finish the edge before it sets up.
Or perhaps someone has some suggestions on how to use levelquick in this application.
Thanks.
Larry

The sand and portland cement mix (dry pack) is a good way but takes a little skill.
SLC is the way to go just read the directions carefully.
Your concrete floor must be very clean. Aplly the primer after reading directions and start your pour.
Any imperfections the next day can be fixed with a modified thin set.

Thanks for the reply Leisure.
Do you have any preference for the brand of SLC to use.
The local building supply place has LevelQuick and one of the tile shops suggested using Ardex Feather Finish.
There is a Lowes and HD fairly close but I haven't checked their SLC products.

I have only used LevelQuick but I believe Ardex is good they have been here a while.
Just read the directions carefully. So much info on the backs of bags and containers.

Larry FYI,

The sand/cement method wouldn't work very well in that you wouldn't be able to accommodate the required feather edge. It also needs to be a minimum of about 3/4", so that's out.

The Level Quick is as good a SLC as any other. It isn't difficult to use. The problem is going to be getting it down and maintaining the edge to feather. SLC will feather but it is tricky and requires a little experience I think. SLC is sticky to the trowel and will drag along with the trowel making it very difficult to feather. It's not like sand and cement.

Here's what I would do.

I would determine a line along the 18' run. Then along this line screw down a temporary dam. Maybe a piece of 1X2. Pour the SLC in the low area allowing it to settle against the temporary dam. You would have be sure of your elevations.

Once the SLC has set hard, remove the dam and use a floor patch to fill/feather to the final point, using the top edge of the SLC to drag a straightedge on.

Keep in mind that the SLC requires a primer and the primer would also be adviseable for all of the filled area.

Bud,
Thanks for the info. I posted a reply earlier but it looks like it got lost. Anyway, I'm going to go ahead with the Level Quick and keep in mind potential feathering problems. I think I'll use a variation of your building a dam idea and just keep the SLC pour back from the feather edge a foot or so. Then when I set the tile I'll feather it out with a little extra thinset.
Thanks again.
Larry

The problem with your idea is that thinset really isn't intended to be used as a serious filler. Anything thicker than what is distributed by the notched trowel should be thought thru thoroughly. Thinset shrinks terribly. You CAN NOT effectively "build-up" with it contrary to popular belief. As it cures and shrinks it will take the tile with it and lippage can result from tile to tile.

Also, the SLC will not roam in a straight line as it is poured. It will meniscus unevenly with out a dam to control it.