I have a couple of questions regarding installation of ceramic tiles.
If there is an existing vinyl floor down, does this have to be taken up or can you just lay Hardi backer down (glued and screwed) over the top of the existing floor and then set your tile to the new Hardi board.
The house I am working on has 2×8 floor joists 16″ oc with a 12′ span between girders. I believe the floor has a 5/8″ subfloor with the vinyl over that. Will the 2×8″ provide enough support for ceramic tiles?
Last…what is the difference between a porcelain tile and a ceramic tile.
Any info you guys can provide would be greatly appreciated.
Replies
I think you need to stiffen up the floor before putting tile over 2X8s. If you have access, the very minimum would be cross-bracing between the joists at four-foot intervals. I don't know if there is an I-joist product available in the 7.25" depth, but if so and if feasible to install between the joists, would stiffen the floor considerably. Since you are in the process of deciding whether or not to take off the vinyl, I think it may be wisest for you to get an expert opinion before proceeding with the tile job.
Porcelain is a type of ceramic.
A ceramic is any solid material formed by the fusion of minerals in a kiln. It includes a vast array of materials, including brick, earthenware, pottery, stoneware, and so forth. It also includes highly engineered materials such as substrates for catalytic converters and jet engine parts.
Porcelain is a particular type of ceramic made of particularly fine materials, fired at a high temperature which produces a material that is very smooth and is translucent when thin.
Among tiles, ceramics can be very soft and porous, such as Mexican Saltillo tile fired at low temperature, or can be quite hard and impervious, and anywhere in between. Porcelain tiles are nonporous and very hard, dense tiles. The unglazed tiles often used in locker rooms, in which the color goes all the way through, are porcelain.
Porcelain is laid like any other ceramic tile. The methods depend on the environment, size, and flatness of the tile, rather than the material the tile is made from.
You don't say if this will be a wet area (bathroom) or not?
As mentioned by others, you need to stiffen the floor. A min of1.25 " of ply equivalent should be the guide. What I would do: 1) remove the vinyl, clean, 2) glue (with PL premium) and screw down another 5/8 or 3/4 layer of ply (AC grade) and 3) lay tile on top of that with a premium latex modified thinset. The hardibacker doesn't add much structural strength compared to another layer of ply, especially with the vinly in between!!. too springy for my taste. CBU's are nice to have in very wet location (shower), but not a must IMO in drier areas. You can also use a waterproofing membrane on top of the ply if needed...
YMMV...
the 5/8 flooring is too thin. A layer of hardie would be nice to set the tile on, but it adds almost no strngth, so if space is tight, skip the Hardie and add as much ply as possible, up to a layer of 3/4. Glue and screw the new layer of ply. Use only ply that is rathed for sheathing or underlayment. Some 1/4 ply is not acceptable.
Generally speaking, porcelain tile is better than plain ceramic. One advantage to porcelain is that you can get 'through body' porcelain, where the color goes all the way through. Ceramic tile has a glaze on top, like icing on a cake. If you have to cut the tile, the through body porcelain won't show the difference in the core color like ceramic does.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
With 2X8's 16oc spanning 12' you have around L300 deflection. Minimum for tile is L360. Adding plywood on top won't solve your underlying deflection issues ( could cause cracked tiles and crumbling grout). Like Les said, you need to get under the floor and beef it up.
jim
Yep, L302 is what I came up with. If you try to tile over this you will have problems. I would consider:
1. Beefing up the joists with blocking between them; and
2. Adding another 3/4" layer of ply, or removing the whole shebang and going with inch and an eighth t&g sturdifloor, the BEST!!!!
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
now that the deflection has been settled ...
the vinyl.
cushion backed or no?
most residential sheet vinyl is cushion backed ...
and you can't tile right over cushion backed ... or add the backer over it either.
if it's a cushion backed vinyl ... tear it out.
I know this as ... a coupla short years ago Hardi said U could ...
then .. by the time my customers floor started showing hair line cracks ...
their "new and improved" pamphlet said "not for use over cushion backed vinyl ...
my guess is someone's lawyer already got to them ...
Jeff
Buck Construction, llc Pittsburgh,PA
Artistry in Carpentry