Energy website (And Underfloor Heating)

http://ec.europa.eu/energy/intelligent/library/publications_en.htm

Has useful infor ranging from energy efficient homes to energy related products. You should be able to download quite a few pdfs but if you are not reply.

riven wrote:

http://ec.europa.eu/energy/intelligent/library/publications_en.htm

Has useful infor ranging from energy efficient homes to energy related products. You should be able to download quite a few pdfs but if you are not reply.

Are you involved?

No but various collegues of mine do research on intelligent grids and some others on clean fossil fuels and fuel cells. They passed round the email at work so I am passing it on to anyone who wants a look. I have not looked at anything much, too busy.
I have a subscription (of sorts) through work.

I want to upgrade my house to underfloor heating, but I can't find a local supplier for the concrete beams for beam and block.



My existing floor is suspended joist with zero insulation.

EvotingMachine0197 wrote:

I want to upgrade my house to underfloor heating, but I can't find a local supplier for the concrete beams for beam and block.



My existing floor is suspended joist with zero insulation.

How does that work ? Where do the heating pipes go ? I lived in a house once with underfloor heating it was lovely ! The concrete keeps the heat better than the air ? keeps the heat with rads.

you put 100mm insulation on top then the UFH pipes and pour a screed on top.

Or there is this system with the insulation designed to slot into the beams.

EvotingMachine0197 wrote:

you put 100mm insulation on top then the UFH pipes and pour a screed on top.

Or there is this system with the insulation designed to slot into the beams.

Why suspend the blocks in the first place ? Could you fill it with rubble ? Or does the blocks technique save on the rubble. I've never seen suspended blocks before.

Yeh, tonnes of hardcore, pain in the hole. You can't use rubble these days unless it's properly recycled.

riven wrote:

No but various collegues of mine do research on intelligent grids and some others on clean fossil fuels and fuel cells. They passed round the email at work so I am passing it on to anyone who wants a look. I have not looked at anything much, too busy.
I have a subscription (of sorts) through work.

Emails were sent to Messrs Ryan and Gormley last week, asking how we are going to attain the 40% renewables target ( and more ? ). I'm looking forward to seeing the reply.

EvotingMachine0197

The system with the insulation between the concrete beams has cold bridging at each of the beams.

You shouldn't have difficulty getting the beams they are called T-Beams and most precast conc manufacturers make them. Most I have seen seem to come from various businesses around the Dungannon area, they seem to deliver anywhere. The concrete blocks may need to be 10.5N block. (check the specification that the manufacturers provide). It is so that you don't go through the floor when laying it. Also give some thought to the screed type and thickness. About 75mm-100mm concrete screed may be better than sand cement, but you need to specify the use or you get large aggregate. Don't forget the vertical insulation around the perimeter of the screed.

You really DON'T want to fill the hallow below the floor with hardcore if there is over 1m of it. It needs to be properly compacted. If you don't you risk the floor slab settling differentially and pushing out your walls along the line of the damp proof course!

Thanks for that Squire. I hadn't thought of the cold bridging on the foam insert method. Good point indeed.

The nearest supplier I can find for the beams is in Mayo or Offaly. They do deliver but charge an arm and leg for it.

The existing floor is 450mm above the concrete base. This is made up as follows:

mortar bed 10mm
solid block block 215mm
DPC
mortar bed 10mm
wall plate 50mm
joist 135mm
floorboards 20mm

I'm sort of planning on doing one room to see how it pans out. The layout of the house, boiler, fuseboard etc. allows me to do this room in isolation without upsetting the rest of the house. The wiring and plumbing under the floor is ancient (~40 years) so I would be upgrading this at the same time as well as adding in some structured data cabling.

Here's a shot under my existing floor. Not very pretty, or warm.

We have underfloor heating, retrofitted about five years ago. We used a nice red clay tile on top, and it holds the heat very well as well as being nice and cool in the summer. I can't remember exactly what is under the tiles, but there is some form of insulation. One of the rooms is warmer than the others - we have finally got around to asking a plumber to investigate.

EvotingMachine0197 wrote:

Here's a shot under my existing floor. Not very pretty, or warm.

It looks freezing. Do the carpets lift when the wind is in the east?

cactus flower wrote:

We have underfloor heating, retrofitted about
five years ago. We used a nice red clay tile on top, and it holds the
heat very well as well as being nice and cool in the summer. I can't
remember exactly what is under the tiles, but there is some form of
insulation. One of the rooms is warmer than the others - we have
finally got around to asking a plumber to investigate.

Yeh, I want to tile the entire downstairs. Tiles are possibly the most
suitable surface for UFH as they conduct the heat very well.

I currently have french pine floor laid on top of the old boards, with
a thin (3mm) reflective foam sheet in between. It's not draughty or
anything, but could be a lot better.

Also, the existing radiator flow and return pipes are in the under
space and not insulated very well. Old fashioned lagging. So a lot of
heat is being lost here also.

EvotingMachine0197 wrote:

cactus flower wrote:

We have underfloor heating, retrofitted about
five years ago. We used a nice red clay tile on top, and it holds the
heat very well as well as being nice and cool in the summer. I can't
remember exactly what is under the tiles, but there is some form of
insulation. One of the rooms is warmer than the others - we have
finally got around to asking a plumber to investigate.

Yeh, I want to tile the entire downstairs. Tiles are possibly the most
suitable surface for UFH as they conduct the heat very well.

I currently have french pine floor laid on top of the old boards, with
a thin (3mm) reflective foam sheet in between. It's not draughty or
anything, but could be a lot better.

Also, the existing radiator flow and return pipes are in the under
space and not insulated very well. Old fashioned lagging. So a lot of
heat is being lost here also.

Wood floors are lovely too. You could insulate more under the floor?

Why are floors suspended like that in the first place ? Or were suspended ? They're not now suspended like that in new houses. Was it for ventilation ? I've heard it's something to do with keeping damp out of a house or out of the boards. Was it more convenient to do that ?

Your radiator pipes are under there emitting heat into an open space - yikes - but the temperature must come up through the boards a bit ?

I'd imagine the set-up that cactus has sounds very good - stone holds heat for ages and ages - I remember down here in Clare using bricks as hotwaterbottles as a younglad of 20. And you have storage heaters too which are a big brick that holds the heat.

Take your time and you'll do a good job. I swear that house I lived in in the North with the underfloor was lovely. Could you just use normal qualpex in the pipes by the way or does it have to be something special to be embedded in the concrete? Are you thinking about rubble at all ?

Cactus just said you could insulate under the floor but that's a cheapo quick-fix that's not really that cheap - "Rafterloc" is quite expensive from Kingspan but I'd say you want to capture your lost pipe heat do you ?

Here's some Rafterloc in the rafters which you could stick between your joists if you could get under the floor:




But it sounds like you're wanting to go for something like this:

EvotingMachine

If the floor level is just 450mm above the ground, just fill it in with hardcore and be done with it. It will be cheaper and easier. Also no potential homes for rodents.

consider;
10mm tiles,
75-100mm screed on vapour barrier
100mm insulation
100 mm concrete on DPM.

All you need is 100 -125 fill!

You could use a wood floor on battens if the planks are square edged. The heat will rise through the joints, but agree tiles are better. Problem with tiles is you better chose well as you will be stuck with them for a long time. Some tiles are not the same colour the whole way through. Don't use this type at the main entrances as the finish can and does eventually wear off.


Audi

You need cross ventilation below the traditional timber ground floors to reduce the possibility of rot. In times gone by they didn't have polythene and cheap concrete. Concrete is a very good building material for the Irish climate.

Oops. Squire I checked my notes and the existing floor is 400mm, not 450mm above the slab. I was going off memory earlier.

The fill in does sound like a good idea - I have had rats in that space. Not mice - RATS.

I was trying to avoid huge amounts of concrete as I was hoping to do
the job myself. Is the 100mm concrete necessary for a domestic floor ?
would I get away with 75mm and make up with extra hardcore ?

Or what about:

75mm small aggregate concrete + UFH pipes. Levelled and floated. Maybe some A146 mesh in there.
100mm insulation
DPM on blinding.
225mm compacted hardcore.
______________________
total 400mm

Does that sound too weak ? It's a shit load of hardcore - about 15 cu.M for the whole downstairs.

In the end I really want a well insulated solid floor. I've seen 600mm tiles put on suspended joist floors and these big tiles just crack if the wooden structure is not rigid enough. Parts of my floor are like a trampoline.

These guys quoted me €2400 for the screed (60sqM 40mm deep)

EasyScreed

What Squire is saying is right EVM - concrete IS very good for the irish climate somehow. It's the best combination to deal with dampness and warmth/cold. Wood insulates on the surface but needs ventilation or else it rots cause the air is damp. And damp air is uncomfortable.

A properly done floor will be like a whole new heating system for you. What do you do with the pipes by the way - tap off the existing rad system and lose one or two rads ? Because a well done floor will be a huge heated block of concrete if done right (I'm convinced that a solid fuel boiler plugged into your pipes alongside your oil or gas burner would be an investment worth thinking about as oil and gas go up in price)

But just the incidental pipework under a tiled floor that leaves the concrete warm for hours afterwards is very pleasant. I'm telling you concrete holds heat well. Are you going to do it all yourself ?

EvotingMachine0197 wrote:

EasyScreed

Get some exercise ...

The plan is to keep the rads upstairs and convert to UFH downstairs. I'll have to get one of those mixer units and some thermostats and all that jazz.

UFH is also quite suitable for solar heated water as it operates on a much lower temperature than a rad system.

I usually do everything myself, but this job will be especially upsetting for the housejold as the entire floor has to come out. I may have to do it in 3 phases, or else get a builder to do it when I'm on holidays.

Myself and Squire can do it for you - here we come to save the day



Is the UFH piping something that releases heat to the environment very easily - or absorbs it ? There's a zinc oxide paint you paint the bars with and it only reflects 5% of the heat and absorbs the rest. Are you considering connecting solar panels to it ? Would that work - the sun heating up your underfloor pipes - how cool would that be ?

Is the base you are applying all this to a good solid concrete base? My instincts would be to increase the thickness of your screed to 100mm and yes use a concrete screed. 40mm screed quoted is plain daft and I would price around. Screeds can break up if too thin especially going over pipes, electrical conduit etc. It is like a biscuit sitting on top of your vapour barrier. Are you power floating the concrete if so I would imagine you don't want a highly smooth surface or the tiles may not adhere.

Don't forget vertical insulation around the perimeter and a vapour barrier on the warm side of the insulation.

Also with underfloor heating keep joints in the pipework below floor to a minimum, if possible NONE. I have uses bog standard flexible plastic pipe fixed to reinforcing with NO joints below the floor in a few rooms in Squire Hall and it seems to work just fine. Probably just good luck. The general prep and plumbing you could do yourself if the family don't mind living upstairs for a month or two.

60 sq m of concrete 100mm thick is 6 cu m or about 18 tons. You won't move this by yourself even if you hire a pump to get it into the rooms. It hardens all to fast, you can ask for additives to slow setting down. Laying a screed is a lot harder than it looks don't even think of trying it.

Even with dehumidifiers it will take a month or more for the screed to dry out enough to lay the tiles.


Audi

That picture brings back memories of this last month. The Pain.