advice please

[jaykay]

hi i was hopping someone may be able to help me.i am having a conservatory built in 2 weeks time.
i want to install ufh matt and would like to know what level to ask the installer to leave concrete
base to allow for the matting etc so the floor tiles just finish below back door bottom.
also how long should i leave concrete base to cure befor starting installation of heating matt.
hope these questions makes sense and thanks for any help in advance.
i live in suffolk

 

[bugs183]

It all depends on how thick the underfloor heating mat is you plan to use and whether you are going to use an insulating board underneath the cable.
If you use insulation board and it is how i would do the job make sure it is a cement type board, not the cheap flimsy foam type and that it is properly adhered to the floor with cement based adhesive, not silicon or contact adhesive which most people seem to think is acceptable.
Also make sure you use leveling over the u/f/h cable as this stops hot spots where the cable meets air pockets and also protects the floor as it is being laid.

 

[Rookery]

Roughly 3mm adhesive + 10mm insulation board + 6mm ufh/slc + 5mm adhesive + 10mm tile, adds up to 34mm. Plus a bit of clearance.

 

[micko]

Roughly 3mm adhesive + 10mm insulation board + 6mm ufh/slc + 5mm adhesive + 10mm tile, adds up to 34mm. Plus a bit of clearance.

This sounds good. Better to be too low rather than too high. 40 mm

 

[jaykay]

thanks for all your help.just help needed with the last part of my question.how long should i leave the concrete base to cure befor i
starting the heating project. also just noticed u heat are to far from me so will use their products

 

[Uheat - Keith]

Hello Jaykay,

6mm OR 10mm insulation boards for optimal performance and to help the performance and running costs of the our Elektra underfloor heating system. Onto a load bearing base the 6mm OR 10mm insulation board will need an overall extra thickness of 8mm OR 12mm: 6mm OR 10mm board with 2mm powder flexible tile adhesive under the boards to fix.

Our Elektra Mat are 3.9mm thick.
After the Mats are installed, one of the following two ways are used to finish the area:
A) A powdered flexible self-levelling compound is used to cover the underfloor heating at approximately 5mm in total not in addition to the 3.9mm cable thickness. Then powdered flexible tile adhesive at approx 3mm & Tiles at XXmm thickness.
OR
B) A powdered flexible tile adhesive is used to cover the underfloor heating & fix the floor finish at approximately 6mm to 8mm in total not in addition to the 3.9mm cable thickness & Tiles at XXmm thickness.

The Insulation boards can be our Marmox Construction Board, OR Ekoboard Insulation Boards.
Ekoboards are Closed Cell, Extruded Polystyrene and have the same Insulation values as Marmox boards. Ekoboard just do not have the 1mm cement coating top & bottom. If you are going on a load bearing concrete/screed base, you will not need to 1mm concrete skin on the boards because it is already in the floor base.

Check with your Builder on the time needed for the screed to dry out.

Warm regards,

 

[Rookery]

Its at least 1 day per mm thickness of screed and probably longer if the screed/slab is quite thick. You could use a green screed adhesive that allow you to tile sooner. BAL do one, but its expensive and horrible to use. Alternatively an anti-fracture membrane such as Ditra but thats not cheap either.

 

[jaykay]

thanks for all your help.will take your adsvice on curing time rookery.
will also be visiting your depot,keith for the heating matt etc.hope the autumn offer and 5% discount still applies
in early jan.

 

[Uheat - Keith]

Hello again Jaykay, e-mail over your Full Post Code Address and I will enter you into our system, together with notes to say Tilers Forums and Special Offers.

Warm regards,