Help for first time floor tiling please

[Evilc]

Hi, this is my first post on this site so please forgive any silly thoughts.

I am gutting my kitchen and have purchased 15 sq m of porcelain semi glazed tiles 600x600 mm. I have read loads and discover that I need to put down a new subfloor and rip up the current old chipboard. My intention is to put down 25mm exterior grade plywood onto 400mm spaced joists and prime back and edges of plywood with APD, put in support noggins at unsupported edges and screw down with spax screws every 300mm.
However I am confused about which of the myriad of adhesives. I bought some weber.set SPF but now think this is probably wrong for such large tiles. I understand that the rapid set adhesives may be a little more flexible but as I am not an experienced tiler I am wary of being good enough to use it before going off.

Anyway, I would appreciate advise on 1) am I ok with my floor spec? 2) which adhesive ( preferably Bal) to use? 3) using levelling clips & wedges? Many thanks

 

[DHTiling]

The adhesive is fine , the slow set SPF from weber and the rapid set SPF are both equally flexible to C2-S1 ... but i am not a fan of tiling directly to ply and i would also use hardibacker 250 (6mm) for a more stable installation.. making sure th eply is deflection free and cross bonding the hardibacker to plywood joints and also using an alkaline resistant scrim tape for the hardibacker joints.

 

[Evilc]

Thanks for the quick reply Dave. Don't know what C2-S1 means I'm afraid.
It seems the more I read the more confused I get. There appears to be a camp where some people think it is quite ok to directly tile on to 25mm ply and others who advocate a backer board! I am certainly not dismissing your valuable advice but my problem being the overall floor level of 25mm ply + 6mm hardie + 10mm tiles + tile adhesive? In your view, is the hardie a recommendation or a must? And if I go directly onto the ply, is the adhesive still ok? I am not saying that I will ignore your advice, just to say that it will present me with a problem!
thanks again

 

[Ian]

If height is an issue, use 18mm ply + 6mm hardie, just make sure the ply layer is defection free before overlaying with hardie.

 

[Evilc]

Thanks Bri, another question is, should the ply be a hardwood grade or is a WBP softwood ok?

 

[steve187]

here is some information on adhesive types, courtesy of another forum member .

Type C - Cementitious (Cement based Adhesives)
Type D - Dispersion (Ready mixed / Tubbed)
Type R - Resin (Epoxy)

Extra characteristics are described by the numbers and letters below

1 - Normal Adhesive
2 - Improved Adhesive
F - Fast Setting
T - Thixotropy (Reduced slip/ Slip Resistance)
E - Extended open time
G - Grout

S - Elasticity / Flexibility / Deformability
S1 = Deformable (Flexible)
S2 = Highly Deformable

 

[Evilc]

Thank you all for your help. Have decided to go for broke and use 25mm ply plus 6 mm Hardie, all screwed and fixed as advised. My final question is: will the weber.set.spf be ok to fix the hardie ( as well as hardie screws of course)?