Remodeling the Kitchen - Part 4

In Part 1 of our kitchen remodeling adventure we saw what we had to work with.
In Part 2, we came up with a plan and started demolition.
In Part 3 we installed the sub floor and removed part of a wall.
In this Part we will prepare the sub floor for the tile by laying cement backerboard.

Here we have the Kitchen and Breakfast nook ready for tile, right? Not so fast! First we need something underneath the tile that support the tile better than plywood - backer board.

We purchased Hardibacker back board from our local Lowes. It came in 3'x5' sheets (you can see them stacked on the floor in the photo above) and we purchased enough to cover 300 sq. ft. (about 8% more than we needed). You will need to lay some sort of cement backerboard before laying tile if the tile will be over a wood or plywood subfloor. If you are laying tile over concrete, make sure the concrete is in good shape without any cracks, humps, or bowls.

Follow the manufacturer's instructions when laying the backerboard. This is how we did it:

1. Mix some thin set mortar to peanut butter consistancy.
2. Using a trowel with 1/4" notches, spread the thinset mortar on the subfloor. The "valleys" of mortar created by the notches should have just a thin coat of mortar covering the subfloor. Using the notched trowel will ensure a flat and even application of mortar.
3. position the backerboard on the bed of mortar. Make sure there is an even bed of mortar underneath the board. Leave a 1/8" gap between boards - you can use tile spacers for this.
   
4. Screw the board down while the mortar is still wet. The Hardibacker brand board we purchased already had the screw pattern embossed on one side. If yours does not, put screws evenly spaced about 6"-8" apart. One full sheet of 3'x5' board takes 54 screws. A note on screws: there is a certain type of screw that the manufacturer may recommend due to its self counter-sinking head that screws just under the surface of the board and its extra water resistance. I found regular 2" coarse thread drywall screws, which can be purchased much cheaper in bulk, worked just fine as long as you made sure the head of the screw was flush with the backerboard.
5. Make sure the seams of the boards do not line up with each other, in other words, do not make a simple grid where four corners meet. Offset the pattern to where only two corners ever meet.
6. If there are any low spots in the floor or if the floor is slightly out of level, you can use a bit extra mortar to even the surface out. You want as flat of a surface as possible, especially if you are laying large tile!
7. Use special cement backboard tape (it looks like mesh or drywall tape) and tape and mortar the seams between boards.
   

I have some additional tips for laying the backerboard:
To cut the backerboard, use a carbide tipped knife to score the board. With the board well scored, snap it along the score. Traditional cement board can contain asbestos and even the newer types of backerboard that do not contain asbestos are still dangerous if you inhale dust particles. This is why you should cut the boards outside if possible and avoid using any cutting method that creates dust, like sawing. If you have to cut a lot of board, you can use a carbide blade in a circular saw but be sure to wear proper eye, ear, and respiratory protection! If you have never tiled before, working with the backerboard and mortar is good practice for the upcoming job!

Here is our kitchen and breakfast nook with the backerboard laid down and ready for the tile.

Our next installment of our kitchen renovation will be laying the tile. At this point of the project you should be excited about almost having the floor finished.!