Home & Garden

Kitchen tile...installing over existing floorboards?

  • Last Updated:
  • Jan 25th, 2012 8:01 am
[OP]
Deal Addict
Nov 9, 2008
1278 posts
318 upvotes
Toronto

Kitchen tile...installing over existing floorboards?

Hi there,

We've been renovating a 1940's bungalow for quite a few months now and have recently torn up the old kitchen floor (1/4 ply with 3-4 layers of old vinyl tile), leaving us with an exposed plank floorboards over the joists. We have completely re-secured all of the planks to the joists with about 400 screws; those things are nice and solid now.

The rest of the first floor has original 1/2 thick tongue 'n groove birch flooring, laid directly over the plank floorboards, which is in great condition so we are planning to keep it. We removed a wall between the living room/kitchen and the living room/dining room, so it is now open concept.

We are planning on putting tile down in the kitchen, but this poses a due to the rest of the floor being only 1/2 thick hardwood, meaning a slopping transition piece would be required. Obviously if we can avoid this and have the tiles level with the rest of the floor, it would be preferable.

I myself haven't done much tiling, but consider myself pretty "handy" and have a number of family members who are as well.

My question is this: An extended family member was suggesting that as we have re-secured all the floorboards, we may want to fore-go putting a backing board (cement board or plywood) as it will add additional height. Instead, he suggested bracing the floor below with 2x6's and plywood, and running a bead of construction adhesive in between the floorboard gaps for additional strength. I'm assuming we would then just lay Ditra over the floorboards and tile over it.

I myself haven't done any tiling before but consider myself pretty handy. Any feedback or thoughts are greatly appreciated!
5 replies
Deal Fanatic
User avatar
Jan 18, 2004
6547 posts
260 upvotes
Markham
What are the dimensions of the joists?

Use this calculator to determine if your floor is strong enough for tiles: http://www.johnbridge.com/vbulletin/deflecto.pl

Also good reading and info on: http://www.johnbridge.com/vbulletin/

In general, you'd want double layer of plywood glued and screwed, then ditra and tiles. I assume floorboards can count as one of the plywood layers, but best to ask the experts at johnbridge.

As much as same height floors is desired, a proper install that won't crack is more important even if it means sacrificing floor height.
This space for rent
Deal Expert
Aug 2, 2001
15756 posts
5944 upvotes
jacquesstrap wrote:
Jan 24th, 2012 3:19 pm
I myself haven't done any tiling before but consider myself pretty handy. Any feedback or thoughts are greatly appreciated!

I would talk to the company that manufactures Ditra directly. If your scenario is covered with their warranty then it's acceptable (in my mind). Here is the instruction manually which includes details on the subfloor:
http://www.schluter.com/media/DitraHandbook.pdf

It appears they make a new (to me) product call Ditra XL that is meant for going over subfloors made of a single piece of wood.
Deal Fanatic
User avatar
Apr 4, 2009
7688 posts
777 upvotes
North York
If I read OP's kitchen subfloor correctly, it is just planks. How much gap between the planks?

And OP won't be putting an additional sheet of plywood or cement board ontop?
[OP]
Deal Addict
Nov 9, 2008
1278 posts
318 upvotes
Toronto
Busybuyer888 wrote:
Jan 24th, 2012 7:21 pm
If I read OP's kitchen subfloor correctly, it is just planks. How much gap between the planks?

And OP won't be putting an additional sheet of plywood or cement board ontop?

This was the suggestion, yes.

The floorboards are 3/4'' thick. The gap between is about 1/4''
Deal Fanatic
User avatar
Oct 22, 2007
6110 posts
1063 upvotes
Mississauga
As Mr. Nobody has suggested, op should apply the numbers in order to find the deflection rate. This will give you an indication whether more support is needed in the substrate. Ditra XL is a consideration as it's also about 1/8" thinner and may help with the transition. Let's hope the proper screws were used in securing the sub floor as you wouldn't want the screw to not hold in the future.

Top