Kerdi installtion ordering question

[jgwufgator]

We started laying our Kerdi last night. I am following the DVD instructions.

What I don't understand is:
Why not put the floor down first? Kerdi band around perimeter of floor. Place corners. Walls. Kerdi band on wall corners.

That way all water flows down without flowing down into seams.

We only got the Kerdi band placed in the vertical corners, floor sides, and corners. Looking at it, it seems like water could flow downward into the seams between the corners and the vertical kerdi band. I am getting nervous!

[ddmoit]

Josh,

Schluter maintains (with testing and experience) that it just doesn't matter which way the seams are overlapped, so long as they are 2" or more. Some folks probably do the floor first - but then they have to protect it.

[jadnashua]

Yep, that's right, doesn't matter. The material is hygroscopic - it repels water. Water won't wick more than about 1/4" even it is continually submerged. In fact, you could do just the walls except for the last row, then put down the mud pan, drain, then Kerdi it and the seam. That way, you are walking around on a flat floor and don't have to worry about messing up that surface. As long as you get the minmum overlap, it will be waterproof.