I'd like to tile my exterior concrete covered entryway landing. It's about 8'x 10'. The sides are level, but there's sort of a trough up the middle, worst case about 1/4" from flat. There is about 1/8" slope per foot too, for water. The concrete is over 50 years old and there are no cracks, so it's extremely stable.
Is there someway that I could screed material over the middle into the "trough" to make this flat? If there was no slope, I would use a self-leveling mix, but that's not the case. I've thought about grinding down the sides, but it's a bit messy and seems labor intensive.
I'm considering using tile that is about 15" to 18" square.
Any suggestions appreciated! thx