U/floor heating with timber floorboards? To do or not to do?

[mcgrata]

V interesting topic

The reason anyone would want UF heating in an old house is pretty obvious (works with 24/7 applications, old houses suit no rads) so interesting that BBs boards warped and restricted heat output

I was discussing this with someone the other day and they swore me blind you could get engineered boards with old pitch pine sliver on top of engineered backing. This (they said) would allow aesthetically pleasing boards to be put down over wet UF heSting solutions. However I can't find the boards in question. Does anyone know do they exist? If you put old floorboard on top of engineered backing does this solve the problem? It almost strikes me like Ashlar facing on top on render... Create the impression of cut stone with the benefits of traditional construction. Any thoughts? Does this exist? If so which suppliers? Thanks!

 

[giddy2g]

Hi, I know this is a really old topic, but we're currently putting in UFH and about to relay the pine floorboards back on, and was wondering blissbaby if you would mind sharing some more details? Do you know how thick your floorboards are, and was the house unheated for a long time before the heating came back on? Also did you have screed as part of your UFH installation?

Thanks!

 

[Deleted member 174758]

It really doesn't matter if the house was unheated for a "long time" (i.e. months) TBH, so long as the house was dry and weatherproof to start with. The question you need to answer is, what type of heating has the house had in the past 5 years or so? It's basically simple. If the house has been centrally heated for any length of time the woodwork (including the floors) will have dried out, probably to between 6 and 8% RH. That is very dry, especially when you consider that air dried timbers normally get installed into houses at 14 to 18%RH and will reduce over time to 10 to 14% RH in a solid fuel fire heated house. The effect of introducing major heating beneath a timber floor made up from timbers more than 50 years old and which has never been central heated will be to cause the floor to shrink. That's how wood works. Yet customers never want to listen when you tell them this

 

[giddy2g]

Great - thanks that was a really useful answer! Our house has been centrally heated with radiators, so hopefully that means the floorboards are less likely to warp - although I am still nervous re it having not been heated for a while as I can see the relative humidity going up in that time, and the floorboards would have not been close to direct heat as they will be with the UFH pipes.

 

[j_man]

Hi Giddy2g,

How did this work out in the end?


J.

 

[chappers]

Why are people still asking how this worked out, the answer is it doesn't, when you change the way the timber is heating , you will change the way it reacts, the only real option is to lay the floor let it do it's moving and then take it up re plane it and then relay it, but then as soon as the UFH is turned off the timber will start to absorb moisture from the air again and expand....repeat cycle. It really doesn't work. engineered flooring is really the only suitable wood to be laid over UFH.
Personally I just don't get the current obsession with UFH

 

[j_man]

Warm feet.

 

[chappers]

slippers

 

[cjard]

Lower comfort temperature. Save the whales!

 

[cjard]

That said, if people are obsessed with doing away with rads, and they're undertaking a full renovation, why not put the ufh pipes in the walls..

 

[Nozzle]

That said, if people are obsessed with doing away with rads, and they're undertaking a full renovation, why not put the ufh pipes in the walls..

Because heat only rises, so you'd have a cold room, cold feet, expensive fuel bill but maybe some warm picture frames. The only way you can get a WALL to warm you is if it radiates rather than convect.. and to do that it needs to emit infrared "light". And to make a brick emite infrared light would need your house to be on fire.

Nozzle

 

[cjard]

Heat doesn't rise, warm air does. A warm wall will warm a room via convection just as much as the floor will. Or a radiator.

 

[Ric2013]

Interesting that people have had bad experiences with this. I'm currently in the middle of laying my own floors with some rooms reclaimed (from my own house) and some rooms new boards all over UFH based on the fact that a friend of mine did the same thing on his house. 'Did it work?' I asked him. He said yes, but the nails he used to hold the floorboards tend to creep up and once a year he has to punch them level again. He didn't lay the boards too tight, so they probably do gap slightly during the heating season, but he (and I) aren't bothered by that sort of thing. I'll be screwing, not nailing.

I think it depends what level of flatness of floor you want to achieve. Ideally you'd use narrow boards and they'd all be quarter-sawn. Try getting that from your local Jewson's though lol.

I may remember to keep you updated.

 

[Agile]

Because heat only rises, so you'd have a cold room, cold feet, expensive fuel bill but maybe some warm picture frames. The only way you can get a WALL to warm you is if it radiates rather than convect.. and to do that it needs to emit infrared "light". And to make a brick emite infrared light would need your house to be on fire.

Nozzle

Not really!

Infra red radiation is in effect radiated heat and will be radiated from walls.

But the amount radiated depends on both the temperature and the surface. Matt black is the best emitter colour and white pretty poor. So heat from walls would not fit in with people's idea of a good colour scheme!

Infra red heating is very good and efficient and very rapid heat up. Often used from overhead units in warehouses and churches!

 

[Doggit]

Matt black is the best emitter colour and white pretty poor

The colour of the emitter is actually immaterial Agile, black absorbs heat from the sun, and white reflects it (funny how Arab men war white robes, but the women wear black though) if the walls were emitting the heat, it is possible that they would just be acting like giant LST radiators.

As to the original problems, as there are spreader plates to go under wooden floors for UFH, then as long as celotex is placed below them, this should have achieved his aims. The caveat would be how well the property is insulated as to how effective the solution is.

As this is an old thread, and update would be nice.