Installing tile floor using Ditra and heated floor mat

[joeyL]

Hello, we are getting ready to install a new tile floor. Want to use ditra and the heated floor mat.
Questions:
Do we install the mat or ditra first?
Only wanted to use the floor mat in certain areas. Can we do that?
If so, can we build up the thinset so the floor remains even where there is no mat?
Appreciate your help.

 

[CallMeVilla]

Ditra first, mat second. Yes, you can "zone" the mat usage and "yes" you can make up the difference using thinset. Should have nice warm toes.

See Page 12 of the Ditra Handbook: http://www.schluter.com/media/DitraHandbook.pdf

 

[joeyL]

Thank you! I was hoping I could do the mat like this.

 

[joeyL]

One more question (so far)... We have 5/8" subfloor, 10" joists, 16" oc. Can't see the length. I see where some installers state that you can get away with 3/4" subfloor under 12x12 porcelain tile. If we use the 1/8" Ditra, does that make the subfloor adequate or does the subfloor need to be 3/4" prior to the Ditra? If not, can we use the Ditra XL to compensate. We will do what is correct, but hoping the XL would work.

 

[Jaz]

Joey,

Please note that CallMeVilla got the info backwards. The warming mats go in first, then ditra over.

If everything was done right and still in good condition, 5/8" @ 16" oc meets minimum standards. (thank you cheap-*** builder for using 5/8")

You should be able to figure what the span is for the joists, you don't haveta see them to know where they are. You can use regular Ditra, but if you can find it, Ditra XL is preferred.

Jaz

 

[joeyL]

Thanks Jaz. We ended up adding 3/8" plywood over the existing subfloor. When the existing flooring was removed, the subfloor looked like it needed some help. We will start tiling in a few days. Looking forward to this project being completed!