Which wet underfloor heating system

[Morticer]

Hi All

I am looking at wet underfloor heating systems and my head is beginning to hurt already! I am doing a self build with the help of an architect... well some help! He has designed a floating floor system that having spoken to polypipe will not work with natural stone or tiles due to the problem of deflection in the insulation. Damn! Back to the drawing board!!

Does anyone have any helpful advice on a cost effective approach to installing a wet system? It will cover a single room of about 25m2 so no need for zones etc. I have to build the extension floor up by about 150mm (finished) to meet the floor level of the existing house and I'm not sure how to go about it now. The floating floor solution was kind of off the shelf and could have been done quickly, now I have to think about screeding the floor and a whole lot more work.

Thanks in advance

Leo

 

[Groovejet]

Weve just done one .
Cover full area in kingspan insullation or equivallent , then polythene sheet the area making a 150mm or so upstand around the edges of room.

The internal/external corners should be cut tight into them, and then smaller sections of sheet should be denso taped into the areas to completely seal. Pushing and cutting tight into edges illiminates air pockets and weak spots, and also stops areas around the top edges of the screed not filling correctly!

Install the underfloor heating in one continuous loop without any connections, and take pipe back to where manifold is going to be situated.

In a perfect world you should pressure test, either wet(connected up to manifold and finished) or Dry(pressure test pump where you can pump a small amount a water into pipework and check for pressure loss)

Then a slurry can be pumped in to create a screed of the desired depth.
There are many different mixes that are being used and created.. Cement based , latex......!!! Speak to your contractor for specifics (Minimix are one)

The mix we got was made especially for our jod and was a trial to see how it settled and finished .
The end product was excellent, really smooth , very level and only one or two very small air bubbles. It was that good the customer was thinking to keep it as a finished surface!
The size was 40m2, so we had to cut expansion joints into it.

Your specs. and measurements will be different of course but the principle the same, just speak to your architect on getting your specifications correct.