Electric underfloor bathroom heating

JohnBoy

Hi,

Doing a bathroom next in our rennovations, converting a box room above the existing bathroom into a bathroom and then converting the old bathroom into a utility room.

So to the floor covering.

The way i see it we have 3 main options, bare floorboards, tiles, or lino.

floorboards, look good, not very waterproof, warm
tiles, look good, fairly waterproof, cold as all hell.
lino, looks not so great, waterproof not much colder than timber.

I'm looking at this from the point of view of that yikes the floors cold sensation.

has anyone installed one of those electric underfloor kits you often see. not in the whole house now, just the floor of the bathroom (around 3sqM).

any thoughts on em, opinions or experiences? to me they seem ideal, the appearance of tiles but not the freezing cold bit. of course the other question then is what sort of energy they'd use

gonk

I have a Devi-Heat (electric) kit under a tiled en-suite bathroom floor, works very well. Nice and warm underfoot. It's rated 100 watts, so no more energy use than a light bulb.

On the other hand, we put a much bigger Devi-Heat kit under our new dining room floor when extending and it was a disaster. System stopped working twice, involving excavating terracotta tiles and concrete sub-floor to repair. Contractor blamed builder, builder blamed contractor, etc etc etc. When it failed for the third time, I just wrote it off - hadn't the time or patience to pursue it with the two of them.

So, I'd say you're fine with a small system like you describe, but I wouldn't go any bigger than that.

Viking House

Hi Johnboy

We fit a lot of heating cables in bathrooms and find them very good.
We run the thermostat through plastic 10mm piping so it can be changed if there is a problem.
We prefer the cables to the Devimats as they are cheaper and more versatile.

GreeBo

gonk wrote:

I have a Devi-Heat (electric) kit under a tiled en-suite bathroom floor, works very well. Nice and warm underfoot. It's rated 100 watts, so no more energy use than a light bulb.

On the other hand, we put a much bigger Devi-Heat kit under our new dining room floor when extending and it was a disaster. System stopped working twice, involving excavating terracotta tiles and concrete sub-floor to repair. Contractor blamed builder, builder blamed contractor, etc etc etc. When it failed for the third time, I just wrote it off - hadn't the time or patience to pursue it with the two of them.

So, I'd say you're fine with a small system like you describe, but I wouldn't go any bigger than that.

hey, do you know what was going wrong with your dining room?
We are looking at doing our kitchen/diner aswell...:o

Viking House

I would guess that either the thermostat is faulty or somebody put a cut in the cable with a shovel of something.

gonk

GreeBo wrote:

hey, do you know what was going wrong with your dining room?
We are looking at doing our kitchen/diner aswell...:o

We had Devi-Heat cabling in the ceiling and floor. The ceiling cabling was fitted and tested by the heating contractor and then the plasterboard ceiing was installled. The ceiling cabling was damaged at this point and never worked. The only way to fix it would have been to rip it all out and start again. The ceiling cable was only to supplement the floor cable in very cold weather, so we left it.

The floor cabling was laid on the sub-floor and more concrete poured on top. The builder damaged the cable before pouring the concrete on top, but realised this and called the contractor back to repair it (he stuck a piece of Wavin pipe over the break to keep the concrete off and leave access for the repair). Repair done, we filled in that spot with concrete, got the circuit tested OK and tiled over it all.

It worked for a week before failing. The repair was immediately suspected, that spot was dug up, the repair re-done, and new tiles laid. It now worked for about three months before going again. Another spot was dug up, a repair done and away we went again. This time we got a month out of it. At this point we gave up, not wanting our floor to be covered in a patchwork of repairs.

In my view, the installation was badly done but the system was in any case too fragile to trust around your average builder. If you do go for it, it is imperative to keep a detailed scale drawing of exactly how the cables are laid or it can become impossible to trace and repair faults. This was not done in our case and was entirely the heating contractor's fault.