Hi,

I will be helping my parents re-do their kitchen (13'x13') with tiles. The house is about 55+ years old and it uses 1 x 6 pine strips(actually 5.5 x .75 inch) as subfloor through out the house. The strips have about 1/4 inch gap in between.
Can someone suggest what is the most cost effective and yet durable surface for the tile?
I am thinking of using wonderboard (from HomeDepot) set with mortar between exiting pine subfloor and the wonderboard, but then I also heard people would just use roof nails to fasten the wonderboard to the subfloor... which is best? Or is there a better alternative to prepare the tile surface.

Thanks,
TrueNorth

Make sure the existing boards are screwed tight to the joists and then install 5/8" exterior grade plywood using 1-1/2" deck screws and don't worry about having the ends of the plywood directly over the joists ... in fact try to position them somewhere between the joists.
An isolation membrane should be used over the plywood in preparation for the tile.

Thanks Harry!

One last question, the plywood needs to be tong and groove or it is not important?

Cheers,
TrueNorth

Over a diagonal 1x6 floor I would use T&G and installed as Harry suggested. Also, don't use any glue to install the plywood.

Butt end spacing is at 1/4 the span between the joists.

So I went to HD and Rona in the last couple of days shopping and pricing out my project. For the isolation material I looked at Ditra and was suprised that it was a little pricy (around Cdn$3.5/ln ft). What other options do I have for the isolation material?

Thanks,
TrueNorth

You are only going to save on average about 50 to 60 cents a square ft using cement board as an underlayment.

The benefits of using Ditra far outway the small extra material costs.

Are you saying that Ditra in Toronto is $1.07.....

On average Ditra is about $1.80 a sq ft.
1/2" cement board averages $1.19 a sq ft plus the CBU screws and a small amount of extra thinset. So adding screws etc. the material price differences are minimal. And we haven't even talked about labour yet. For a DIY that doesn't matter.

HD sells Ditra for $5.95 a lin ft (3.28sq ft per lin ft)or $1.81 a sq ft.

I got takin' in by the $3.50/lf.
My math is not good but is sounded like $1.07..
Just a mathematical error I'm sure. Dang.....almost headed to Toronto this weekend to get some Ditra.

Guys,

Thanks for the info.
My price came from my mental note when I was at Rona two days ago... I'll have to go back and double check again. In comparing cement board with Ditra it a no brainer that Ditra is the way to go...


Cheers.
TrueNorth.