ask a silly question...

[bonemachine]

Client wants floor laying (no probs there) but they also want electric underfloor heating. Now do i insist on a spark installing it first or wait till tiles are in place? Never laid the stuff before. Actually whilst im on the subject, would you bury it in self levelling or just cover it with flexi?

 

[faithhealer]

Always latex SLC and get a sparkie after you have laid tiles. check with sparkie where best to put the spur.

 

[Jtsd02]

hiya mate!

never lay tiles over underfloor heating without checking if it works first!! it can go very wrong.if you can get a spark to install it first

john

oh and laying it inot flexi should be ok

 

[brian c]

well Aaron has a different take on this...first of all how big is the area and wht is the substrate?

 

[bigandy]

client wants floor laying (no probs there) but they also want electric underfloor heating. Now do i insist on a spark installing it first or wait till tiles are in place? Never laid the stuff before. Actually whilst im on the subject, would you bury it in self levelling or just cover it with flexi?

there are a few questions you need to ask yourself.
You say about a spark installing it first,what do you mean by that?the mats go down before the tiles!!!
What is the sub floor therefore what insulating materials will you need.
Personally i would bury the cables in latex slc then tile normally on top using flexi addy.
Dont forget to do a continuity test before during and after install.
Dont turn it onto set your addy in fact most should nt be turned on for several weeks,consultwhich ever product you are planning using.

Doa search on here and you will find lots of threads to help you gen up and/or contact aaron from uheat one of our sponsors and am sure he will talk you through everything.
Good luck and hope all goes well

 

[bonemachine]

25m2 and levelled concrete.....

 

[Jtsd02]

if it devi mat heating then flexi is fine, i done way over 30 with no problems yet.it depends on the type of underfloor heating.ask your supplier which adhesive is best.

 

[Leatherface]

The best advice is to purchase the right equipment so that you can check / monitor the continuity etc as you are going. This is invaluable. Will tell you if heating is faulty in first place, will tell you if you nick the cable, will also make you confident that you can hand over to the spark in full working order. I always self level over cable prior to fixing tiles !
Aaron should be able to advise about what equipment to buy !
Also concrete you would be well advised to lay insulation boards prior !!

 

[bonemachine]

the mats go down before the tiles!!!

lol 🙂 even my 2 year old knows that. He's taught me everything i know. Must be all the Bob the Builder he watches......

 

[Uheat]

Hi ya Bonemachine,

First off just reitterate what Leatherface has said. Would definately recommend using insulation boards. Warmup times on an uninsulated concrete floor on average are up to 8 hours but possibly longer!!! Using a simple 10mm insulation board could reduce the warmup times down to around 30-45 mins and making the system a lot cheaper to run.
The next issue, you should be using 200w/m2 into a conservatory if primary heating is to be achieved but confirm that this will defo be adequate with a heat loss calculation. If only floor warming to be achieved then 160w.m2 will be fine.

To answer your initial question. There is no need to get the sparky to fit the ufh but he MUST do the connection to mains and must be part P qualified. The system should also be fitted via an RCD protected fused spur.

I would suggest you try and befriend a sparky for any potential future ufh jobs you may be able to work a deal out (a couple of beers) for connecting up.

You could either leave the cable out at the base of the wall below where the thermostat is going or you could do all the chasing up the wall etc and just let the sparky do the final tests and connection. I would opt for the later as it is more money for you, but if you are unsure then please get leave for the sparky to do.

Using a SLC over the cables is always the best way to go as it helps protect the cables and also gives you a nicer surface to tile onto. Please make sure that a latex levelling compound is used.

As mentioned above, testing the system is vital throughout the installation to ensure no damage to tha cable/mat. I would suggest Underfloor Heating | Installation Accessories | Uheat purchasing the cable monitor (PCM2000) and the multimeter (MM500). The cable monitor is a really good peice of kit which will put your mind at rest while tiling over top.

If planning on using a Mat, then you should work to a max of 90% of the floor area to allow for spacing round outside of room and between mat runs. So if you are looking at 25m2 then you will require around 22m2 of heating mat. With this sized area and using either 200 or 160w/m2 you will require 2 thermostats, as the load is too much for 1.

If you require any help or would like me to price up for you then please give me a bell on the number below or please have a look at www.uheat.co.uk

Thanks