Question for Ajax

[kaharrison9]

Good Evening All. Rather than just pm Alan,I'll keep it in the forum as may be of use to others. Have had a call from a customer who has a Lafarge Agilia Horizontal screed. Is this a calcium screed or does it need any special prep work? Also 2 local suppliers have started stocking a Benfer adhesive(have forgot it's name possible solo....) for anhydrite screeds, have you any feed back on this product> I normally use Gypfix. Kind Regards. Kevin

 

[DHTiling]

It is a cement based screed .. they used to spray a hardening agent over the surface but they do tend to incorporate this within the screed now .. but if there is a waxy surface then this needs sanding off before tiling...

They also do tend to insert expansion joints at around 3mtr lnr intervals...

 

[Ajax123]

It is a Dave says....

 

[kaharrison9]

Thanks very much. Out of interest why not use this cement screed more when tiling is involved. Would it be to do with calcium screeds can be thinner?

 

[DHTiling]

Thanks very much. Out of interest why not use this cement screed more when tiling is involved. Would it be to do with calcium screeds can be thinner?

Because the anhydrite is laid in massive bays with no movement joints , the cement one is laid
in bays no bigger than 3mtr sqr.

 

[Ajax123]

cost, time, quality, stability, environmental, heating efficiency, health and safety, depth, bay size, and design are just a few of the reasons calcium sulphate is used over cement. Anhydrite screed is a technically superior product to cement based screed. There are no doubt tilers who think the substrate should be chosen more to suit them because they think anhydrite a difficult substrate to work with but there are far more problems in the market with sand and cement screeds than anhydrite and its easy to tile to if you use the right sticky.