underfloor heating over existing conrete floor

[chris wallace]

The floor of my basement flat is concrete with loose wooden boards on top. This means there's litte insulation and already starting to get cold - I'm dreading winter! It's an old victorian property, and the radiators and heating pipes are very much in the way.

So, I am thinking I need to put some insulation and a proper floor. Looking about, it seems I could put underfloor heating at the same time and be done with the ugly radiators and heating pipes. But I don't know how to make a choice between electric and water-based system, or have an idea just how much work installation (floor and heating) would be.

Also, although I like the idea of tiles throughout, my friend suggested that it would present problems when I come to sell, because most people don't want tiled living-room or bedroom floors. Would you agree?

I really know very little about all this at the moment. I'd appreciate suggestions of where I should start looking, so I can come back with some more specific questions!

Thanks, Chris.

[The Natural Philosopher]

Use water. Electric too expensive - even on cheap rate.

Not at all. Lots of people love tiles - or better still natural stone.

You can lay laminate over it as well.

You CAN even carpet ove4r U/F. but it reduces efficiency a bit.

Also, allow for at least 50mm polystrene insulation, and 75mm screed with embedded pipes, and probably another 20mm of finish on top of that

Say 150mm in all - avout 6".

[Peter Richardson]

Tiles can always be covered with carpet / laminate flooring.

Electric is cheaper to install, thinner and no maintenance (no moving parts)

Water is probably easier to control and therefore cheaper to run.

Depends how long you intend to stay, if you can justify the additional expence of water system.

Either system probably won't add value to flat, but might make it more appealing to future buyers.

The decision is yours.

Peter

[chris wallace]

Thanks. I'm leaning towards electric. It seems that water would be

*much* harder to install. I already live here, so laying a screed across the entire floor would require all my furniture (and me!) to be moved out while it dries. It seems electric could be installed a room at a time, which would be much easier in the short term. Is that right?

Also, being thinner is an advantage for my flat.

How can I calculate the price differential between the two on running costs? I'm not trying to add value to the flat, just make it warm!

Thanks for the help to both posters,

Chris.

[Andy Hall]

I don't think that there is anything in it. You could install and screed a room at a time. Normally, a UFH system has the pipes running back to a central manifold, so fitting and enabling a room at a time is pretty straightforward.

.andy

To email, substitute .nospam with .gl

[Peter Richardson]

The other poster is correct, underfloor heating can be installed in a room at a time. Although electric is probably easier for the diy'er.

How much does it cost to run? Very difficult question, depends on how much you use it. Water is certainly cheaper than electric but the difference, can't really say.

I can say how much power electric underfloor heating takes. For a concrete floor you should install 160W/m2. If you advise on the size of the flat and how long you would want the heating on each day, I estimate the number of kWh you will use in one day. This should help you establish the cost of running electric heating.

Email me direct if you like.

Peter

[The Natural Philosopher]

About 3:1 at normal electricty rates - i,e. maybe 300 quid a year water, £1000 a year electric.

Unless you only want to heat your floor at 3a.m. When economy 7 or whatever allows you to pull electrons at similar rates.

Its teh same oil they burn in power stations, but they chuck out 30% of the energy as waste heat, and it comes to you in a a huge capital infrastructire of cables transformers and substations. All of which nibbles a few percent off the efficiency every time it passes through them.

Electric heating is totally cost ineffective.

If you aren't going the how awter route, give up and put in rads.

[The Natural Philosopher]

Mmm. I am gettung by with less than 80W/m2. It entirely depends on insulation levels.

Laying more pipe is very cheap and simple tho, once you make the decision to do it at all.

It costs you the pipe, a bit of labour, and a bigger manifold for the extra circuits.