Flooring suitable for underfloor heating - tiles, wood? Advice needed.

My ex is about to put some flooring down over existing wood floorboards, reason being cold rises from the cellar underneath (not habitable, low ceiling). Will be in the hall and small front room. Small house.

She's thinking tiles in hallway and wood flooring in front room, or wood in both.

What kinds of wood are reliable with underfloor heating? Is it only engineered wood squares, or are there some other clever options?

Experiences and advice, including wood and tile options?

Reply to
Eusebius
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Tiles of course are fine.

Some engineered wood flooring is fine - but check the manufacturer's instructions. You might look at kahrs website - they do have detailed instructions and a technical line you can phone.

Reply to
Tim Watts

tack down hardboard to kill draughts. Makes a huge difference

Then you will need to put better than old floorboards and hardboard - suggest ripping up and using 3/4" ply or chip

Wood as in laminate?

Whoa - where did UFH come from?

If you are doing UFH and not using leccy mats then you need to start from scratch and do the whole thing right.

The easy part. laminate is OK with UFH as is engineered wood but real boards may well shrink a lot in winter.

IF this is a suspended ground floor, you MUST shove in as much absolutely draughtproof insulation as you can, otherwise the UFH will heat the underfloor space as well as the house.

That means (unless you have crawl space under the house) ripping up all the floors and starting again.

If you can access from underneath, wedge 75mm kingspan or similar between joists flush with base and foil tape over bottom.

If you cant access from below, screw little L shaped hangers to the joists, and pop the insulation on that, and then go round the edges with a mastic (decorators caulk works and is cheap) to completely seal from draughts.

Put a piece of insulation along any outer walls as well, under the floor

You can then use pipe clips pushed into that to locate the UFH pipes. Which you should lay at around 4" spacing in as many parallel circuits as you need. That will give you about 100W/sq meter at 50C water temp which is OK for a moderately well insulated house.

Put the pipe inflows at the edges and the outflows near the middle

For tile over, I'd lay 3/4" floor grade chip or ply over all that make sure its dead flat by using packing over any low joists.. And use a thick cement bed - at least 6mm - of flexible and quality tile cement.

That's about an inch in total, and if you want to match that with solid wood that's easy enough with 3/4" boards on a 1/4" packing but beware of shrinkage.

For engineered wood us 3/4" chip flooring, a bit of foam underlay and

1/4" engineered wood. That works pretty well. Remember to leave an expansion gap at the edge and cover that with skirting.

The main point is that you cant do half a job with wet UFH. You must lift the lot and insulate properly, and the more insulation the better.

Reply to
The Natural Philosopher

I used kahrs - its fine

Reply to
The Natural Philosopher

But would it not be a better option to insulate under the floorboards?

Reply to
ARW

If you have underfloor heating, wouldn't it be better to insulate/seal under the heating elements? Waste of energy getting it to try and heat colder air than it needs to.

Reply to
Dave Plowman (News)

Try Googling radiated versus convected heat. And tell us how underfloor heating works.

Reply to
Dave Plowman (News)

Insulation under the floor is what's needed for that

For UFH you especially need underfloor insulation

NT

Reply to
tabbypurr

Totally irrelevent.

Heat does not rise. FACT.

Hot air rises, because it expands and is lighter.

Polyplumbs overlay U/F heating panels have such poor insulating qualities that conduction into the ground or below-floor space makes it expensive to run. Even B&Q stopped selling them.

Try googling basic physics.

Reply to
Andrew

And there is no 'air' between the sun and the earth's atmosphere.

Perhaps you live in a vacuum?

Reply to
Dave Plowman (News)

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