Electric Underfloor Screed & Tile Expansion Joints?

[dingers]

Hi

Yes, our French friend Claud who generally translates for us has said the electrician has a initial run up protocol which needs to adherred to prior to laying the tiles. Plus reference has been made to a primer application that is necessary. I am wondering if this is any way similair the tile addhesive addy you refer to.

dingers

 

[Ajax123]

Hi

Yes, our French friend Claud who generally translates for us has said the electrician has a initial run up protocol which needs to adherred to prior to laying the tiles. Plus reference has been made to a primer application that is necessary. I am wondering if this is any way similair the tile addhesive addy you refer to.

dingers

The primer and the adhesive (addy) are separate items and need to be incorporated into any tile installation on any screed. The difference with Calcium Sulphate screeds is the functions that the primer serves. If you select a standard cement based tile adhesive which are admittedly by far the most common available then the primer needs to serve 2 functions.
firstly it needs to "seal" the pore structure at the surface of the screed in order to reduce the level of suction from the adhesive into the screed so that the adhesive does not dry before it has time to set. Secondly the primer needs to form a physical barrier between the adhesive and the screed in order to prevent any chemical interaction between the sulphates in the screed and the cement in the adhesive. This is the bit which catches most tilers out because a standard acrylic primer is not likely to act as a satisaftory barrier unless numerous coats are used. Two is not enough IMO. A much more robust system in this instance would be to use a water dispersible epoxy primer as this serves both functions very effectively.
On the other hand if you select a tile adhesive based on calcium sulphate then there is no risk of chemical incompatibility and you only need the primer to reduce suction which the acrylic primers will do very well.
The attached document might be of some use. It is a translation of the one handed out in France by La Chappe Liquide who supply most of the calcium sulphate screeds over there.
The major difference is the moisture test method which over here is by means of the HAir Hygrometer but in Europe will be by Carbide Bomb test.

 

[Rob Z]

Ajax, We see a lot of LaFarge products here, chiefly portland cement and drywall products (mud, board, etc). I thought LaFarge was HQ'ered in Quebec, but maybe it is a French company?

Dingers, If you have the time and interest, please take photos of any part of the process of the work that is going on in your house. All of us would enjoy seeing the work in progress.

 

[dingers]

Hi Ajax123 & Rob Z

Thanks for another lot of good information.

I have tried uplading pictures on 2 occasions but without any luck. I only seem to get as far as naming a library folder then when I select pictures laptop just hangs. Dont know if its my end or other end but will certainly try again. Perhaps forum admin have an answer.

dingers

 

[Ajax123]

Ajax, We see a lot of LaFarge products here, chiefly portland cement and drywall products (mud, board, etc). I thought LaFarge was HQ'ered in Quebec, but maybe it is a French company?

Rob - Lafarge group founded in 1833 in France as a Gypsum Mining company. Group HQ currently in Paris. Since the they have grown a little and currently sit in the market largest supplier of construction materials in the world although not the largest in all market sectors. The North American and Canadian operation is indeed headed from Quebec. Gyvlon screeds have been around in Canada for a few years now but have only just been launched into the States - Not sure where but I assume the northern states to start with. They are as far as I know the Worlds largest manufacturer of these materials. I am certain you will come across them more over the next few years. Sales in the UK market are currently ahead of where they were this time last year even in a depressed market so they must be doing something right.

 

[dingers]

Hi Ajax123 & Rob Z,

Success, managed to upload pics of project......hope there of interest.

dingers

 

[Ajax123]

Hi Ajax123 & Rob Z,

Success, managed to upload pics of project......hope there of interest.

dingers

Don't know how to say this but ..... where?

 

[dingers]

Hi Ajax123,

The pics are in an Album called "Underfloor heating and screed" attached to dingers. they were also shown on front page of forum. I presume I have uploaded correctly? Am I the only person that can see them.
:mad2:
Let me know if you can't find them I will have another go. I have many pics but have got this habit of boring people with them.

Just learnt how to officially thank someone.
Bye the way the thanks is for your many other useful posts not just the last one.

dingers

 

[Rob Z]

Dingers, will take a look...thanks...

 

[dingers]

Thanks Dave,

I presume thats what I should have done?

dingers