[an error occurred while processing this directive]
Ceramic tile kitchen floor
Dear Ms. Builder: I have always liked the look of a ceramic tile floor in a kitchen. I would like to add one to my kitchen, but the floor seems a little springy. Can I install the tile over this floor? - Joan E.
Dear Joan: A ceramic tile floor is beautiful in a kitchen. It is very durable, resists stains and is easy to clean. Since a kitchen is usually one of the warmest rooms in most houses, the tile will hold this warmth and make it comfortable to walk on in stocking feet.
That unmistakable feel of a "springy" floor is great to walk on and it actually deadens some of the sound from your kid's pounding feet. Most types of floor coverings work great over a floor with a little bounce. Unfortunately, ceramic tile is not one of those floor coverings.
Don't fret! There is still hope that you will have that ceramic tile floor in your kitchen. You will just have to strengthen the flooring substructure to make it more rigid and strong. It is quite a bit of work, but well worth the time spent if you really want your ceramic tile floor.
As a brief flooring #101 course, most floors, other than slabs, are built over large floor joists. These 2 x 10 pieces of lumber look massive, but they do deflect from the weight above. The factors determining their deflection are the length of the joist, its cross-sectional dimensions, type of wood and the spacing of the joists.
Don't run out and sue your builder. Building a house to accepted building codes can still result in a springy floor. If you do put the tile over this type of floor, first the grout will begin to crumble. Next some the ceramic tiles (very brittle) will crack and some may even come loose from the subfloor.
There are several options to strengthen and stiffen the floor so that your ceramic tile will last a lifetime. It would be worthwhile at this point to have a builder or engineer check your floor joists. If they are not strong enough or the span is too long, you will have to support them from underneath, add more joists, or use stress skins on the underside.
Assuming the floor joists are adequate, first, make sure that the existing subflooring is securely attached to the joists below. I often use drywall screws with a coarse thread. These hold very well and are a better option than just driving in a lot of nails.
Once your existing subfloor is securely fastened to the joist, you must cover this with either 1/2-inch thick exterior plywood or cementitious board. This will be the stable base for your ceramic tile. Cementitious board is my favorite, but many people are more comfortable and familiar with working with plywood.
If you do choose plywood, make sure to offset its edges from the edges of the existing subflooring by at least three inches in each direction. If the edges are located closer than this, the rigidity will suffer. Leave a slight gap between the edges of adjacent pieces to allow for expansion.
If you are adventurous, try using the cementitious board. This is laid down into thinset. This thinset bonds the board to the subflooring and it fills in any gaps to keep the board from flexing when you walk on it. Nail it in place with galvanized nails. Several suppliers of this board are Georgia Pacific, USG and W.R. Bonsal Company.
Now you are finally ready to lay down the ceramic tile. An organic adhesive or an epoxy mortar is the best material to use if you chose plywood as the base. If you chose cementitious board, then a latex-modified Portland cement works best.
Send your questions to Ms. Builder, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit www.dulley.com/msbuilder.