Deck mud questions

[kscott0986]

Hello everyone, general contractor here with some questions on a small flooring project.

Doing the flooring in the basement of my own house. 50 year old slab on grade, in great condition. I have bedrooms on one end of the basement, where the floor has been built up with rigid insulation and plywood, and a bathroom on the other end which has been tiled. I need to bridge the gap, which will result in a very gradual sloping floor in between.

It seems that deck mud is my answer here, but I wanted the opinion of the pros to steer me in the right direction. The mud will be 1" thick on one end of the hallway and 1/2" thick on the other end, 9 feet in length, 4 feet wide.

From researching other posts, my plan is to use deck mud, bonded to the concrete with thinset. The finished floor on top will be vinyl planks (ideally glued down, but can be floated if necessary). Will this work? Am I missing anything?

Really appreciate it, been very impressed by the knowledge found on this site so far.

Thank you!

[HilltopRehab]

Not an expert but did a deck mud shower pan recently. The only thing is that deck mud has to be at least 3/4 inch thick. So you might need an alternative means of building up the thin end until it gets to 3/4" and then do the rest with deck mud.

[jadnashua]

It should work well. A bonded mudbed has different requirements than an unbonded one you might do over a wooden subfloor.

You need to ensure you get the deck mud down before the thinset starts to skin over, or, you can use a Portland cement slurry, if you don't want to buy thinset since you'll likely already have some of that on hand.

[cx]

Welcome, Kyle.

What Steve said.

A fella can maybe get away with deck mud tapered down to only half an inch at a shower drain bonded to concrete slab, but in a foot traffic area (more feet in real shoes), I wouldn't wanna take a chance on it.

I don't know just how a fella would bond vinyl planks to a mortar bed.

My opinion; worth price charged.

[jadnashua]

If you were worried about it getting too thin on the lower side, you could do most of it in deck mud, then finish off the rest with a thixotropic SLC. You could do the whole thing in that material, but deck mud is lots cheaper!

[Davy]

It's not by the book but I've mudded many floors over concrete that was only 1/2 inch thick. Pack it down and bond it with thinset like Jim said. As you're backing out, reach over and slick it down with a steel trowel.