03:29PM | 06/27/07
Member Since: 06/26/07
2 lifetime posts
I see a variety of answers to how thick the subfloor must be prior to laying tile. What's the bottom line.

In my case, I have a kitchen floor I would like to tile -- probably with 16" porcelain, but could go 12" if needed. The joists are 2X8 Doug Fir 16" OC, 10'2" unsuported span.

The current floor is 1/2" plywood with 3/8" particle board on top. Everything is in sound condition.

My intention was to float the surface for tile installation or, I could go Ditra, or whatever is a good choice -- but not go cost crazy.

How should I prep the sub floor. It what I have adequate? Should I add 3/8" or 1/4 inch plywood on top of the existing particle board and ply and screw it all into the joists? Should I rip out the particle board and put in 5/8" plywood? What will work, and what would be best?

Thanks for any help -- Rodger

doug seibert

05:28PM | 06/27/07
Member Since: 08/10/02
842 lifetime posts
The John Bridge Forum has a DEFLECTO calculator that checks the soundness of your structure

The large tiles require a stout floor.....Check the some articles in the "Liberry".....register and chat in the forum

"...measure once.....cut twice....throw that one away and cut a new one...."


04:55AM | 07/01/07
Member Since: 07/03/05
283 lifetime posts
rip out the particle board, it has no place being under a tile installation. Put 1/2" underlayment rated plywood, like ACX or BCX,perpindicular to the existing one half inch ply. Leave a 1/8" gap in the seams and fill with cheap latex caulk, use screws at 8" intervals, dont worry about hitting the joist with the screws. Put Ditra or cement board over that. Check the Deflecto to see if you need midspan supports for your 2x8s.


04:40PM | 07/01/07
Member Since: 06/26/07
2 lifetime posts
Why the 1/8" gap and caulk -- expansion?



10:15AM | 07/04/07
Member Since: 07/03/05
283 lifetime posts
Yes, wood expansion must be honored. The caulk keeps the thinset from filling in the gap, which would defeat the purpose of the gap.


Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.


type the code from the image


Post_new_button or Login_button

All bookworms need a good bookmark that inspires them to keep reading. To make this colorful bookmark, cut a rectangular p... It turns out that many bath and kitchen cleansers contain chemicals that are dangerous to the skin and eyes, and often pro... So often we paint tiny nooks white to make them appear larger, but opting for a dark, dramatic wall color like this one—Be... Chocolate-colored walls and large window frames allow the exposed wood beams to take center stage in this small screened p... If you're not crazy about the idea of commingling plants and pool, this modern variation may be more to your liking. The s... Yes, a freestanding garage can become its own tiny house. Artist Michelle de la Vega has all the comforts of a modern resi... There’s nothing like a new set of cabinet hardware to refresh a room. The possibilities are endless: Go modern, rustic, or... Pursue what's known as the stack effect. To achieve it, open the windows on both the upper and lower floors, and as warm a... Like no other floor type, a checkerboard design works wonders to underscore the retro kitchen theme. Vinyl flooring, ceram... Twine lanterns add pops of crafty—but sophisticated—flair to any outdoor setting. Wrap glue-soaked twine around a balloon ... When securely fastened to a tree or the ceiling of a porch, a pallet and some cushioning make the ideal place to lounge. V... Incorporate nature into your lighting scheme by securing a dead tree in a concrete mold and draping your pendant lamp from... For the cost of a can of exterior paint , you can totally transform your porch. Paint the floor a hue that complements yo... In this urban apartment, a standard-issue patio became a serene and green perch by replacing the typical concrete with gro... If you put the washing machine in the mudroom, you can stop the kids from walking through the house in dirty, grass-staine...
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon