Omnie Torfloor vs Between Joist Aluminium Spreader vs Profix Low Profile 15mm screed?

[nezdub]

First post for me. We're looking to retrofit UFH into a 110 yrs edwardian terraced house, overall around 100 sqm split between ground and first. Majority of floor is on suspended timber, except for area in kitchen extension which is concrete.

 

I'll be using 100mm Kingspan PIR everywhere (unless it's redundant in the 1st floor?)

 

Coverings will be tiles in kitchen and bathrooms, engineered wood in living areas and bedroom, and perhaps LVT in hallway.

 

I'm looking to fit it all myself, and have come to these 3 options.

1. Between Joist Alu spreaders - lowest floor build-up but I imagine least effective in efficiency.
2. Omnie Torfloor 2 or similar - chipboard with routes for 12mm pipe. Low enough build-up, but easy to install and can be used with most coverings. However, still have questions around efficiency and effectiveness vs alu spreader plates. (how much better is it?)
3. Profix panels with 15mm screed (18mm if using LVT) - seems best for efficiency but I have concerns on setting it myself. Will have to replace subfloor from boards to ply or chipboard, adding to cost. And floors are not fully level, so may be even more faff. Would this be worth the work vs Torfloor 2 and what efficacy it has?

 

I'd be happy with Torfloor if I know that it will work well in keeping house warm without ridiculous running temps through the pipes.

 

Finally, I am looking not to move the kitchen units in the process and build around fixed units in such a case.

 

I'd appreciate any advice, whether you've looked into this before or have already installed any of the systems.

Naturally, if you ask the companies themselves, everything works great.

Thanks!

[HughF]

Avoid spreader plates, they’re rubbish…

 

Plastic trays on the new floor and chuck a pallet of out-of-date self leveller over the whole lot? Probably the cheapest option.

[Adsibob]

On 22/12/2023 at 11:50, nezdub said:

Coverings will be tiles in kitchen and bathrooms, engineered wood in living areas and bedroom, and perhaps LVT in hallway.

Why so many different floor finishes. I get that you want tiles in the wet areas, but I would choose just one finish for the remaining areas, otherwise you really will have a patchwork effect that will look silly. So match the finish in the corridors to the living and bedrooms.

[Adsibob]

On 22/12/2023 at 11:50, nezdub said:

We're looking to retrofit UFH into a 110 yrs edwardian terraced house

So Edwardian houses aren’t insulated very well, so unless you are massively upgrading the insulation, I’m not sure UFH is the way to go here. What’s the current heat loss the house?

[Iceverge]

 

 

 

Welcome to the forum.  Hopefully all your dreams come true!

 

 

On 22/12/2023 at 11:50, nezdub said:

Majority of floor is on suspended timber, except for area in kitchen extension which is concrete.

 

I'll be using 100mm Kingspan PIR everywhere (unless it's redundant in the 1st floor?)

On 22/12/2023 at 11:50, nezdub said:

Finally, I am looking not to move the kitchen units in the process and build around fixed units in such a case.

 

Before going any further I'd have a think about the insulation. 

 

1. Are you planning on digging out the concrete kitchen floor?

2. PIR wouldn't be my first choice. Something like this would be superior. Ask The Expert - Thermally Upgrading Suspended Floors | Ecological Building Systems

3. I would try to get under the units. There must be a way! How much space in the subfloor void do you have to play with?

4. How much head height are you able to loose in the rooms, doors and stairs dictate this as much as anything. 

[nezdub]

On 24/12/2023 at 13:04, Adsibob said:

So Edwardian houses aren’t insulated very well, so unless you are massively upgrading the insulation, I’m not sure UFH is the way to go here. What’s the current heat loss the house?

 

Thanks for your reply and thoughts on flooring - LVT was just an alternative to the tiles in the hallway, but nothing finalised.

 

We plan on upgrading roof insulation, changing all windows to double glazing (we've just got the keys, so work is necessary), and appropriate underfloor insulation. Then I'll look into internal insulation on front and back walls (Externally facing).

 

I did heat calcs based on the assumed changes (ex wall insulation for now), and reached heat loss of 7,000W, meaning I'd need a heat output of around 80 W/M2 in greater london. With that said I'd like to get a specialist in to do their own calcs.

 

On 24/12/2023 at 10:17, HughF said:

Avoid spreader plates, they’re rubbish…

 

Plastic trays on the new floor and chuck a pallet of out-of-date self leveller over the whole lot? Probably the cheapest option.

 Thanks - it seems like the best option.

 

On 24/12/2023 at 17:47, Iceverge said:

Before going any further I'd have a think about the insulation. 

 

1. Are you planning on digging out the concrete kitchen floor?

2. PIR wouldn't be my first choice. Something like this would be superior. Ask The Expert - Thermally Upgrading Suspended Floors | Ecological Building Systems

3. I would try to get under the units. There must be a way! How much space in the subfloor void do you have to play with?

4. How much head height are you able to loose in the rooms, doors and stairs dictate this as much as anything. 

 

Thanks very much for sharing thoughts.

 

1. Not planning on digging out concrete, will try to bridge the gap between joist and concrete with either omnie torfloor boards or the self leveller on top of plastic panels.

2. I've been reading about the non-breathability of PIR, but many seem to claim that on a suspended ventilated floor it works. I'm happy to use a different type of insulation as long as there is efficient reflective ability for the UFH. Thanks for sharing that article, need to evaluate u-value differentials, but I do prefer maintaining breathability (potentially hindering some of the heat retention).

3. Ideally I'd get it done, so I'll just have to check. At the same time, hard for me to see the benefits of heating under there unless we change the kitchen layout.

4. Plenty of room as ceilings are quite high. As you mention stairs and doors being the main limitation, we'd be ok with losing up to 30/40mm all in.

 

Thanks! I do hope these dreams do come true - would be great to get the character of these old houses coupled with some decent UFH, slightly better efficiency, and no rot!

 

[HughF]

I did PIR between the joists, new chipboard on top. Has made a massive difference to the performance of that room. 
 

Plenty of ventilation underneath still, we didn’t block the air bricks.

[Iceverge]

Sorry I misread about the kitchen with its concrete floor being an extension. Is it recent and does it have insulation?

 

16 minutes ago, nezdub said:

2. I've been reading about the non-breathability of PIR, but many seem to claim that on a suspended ventilated floor it works. I'm happy to use a different type of insulation as long as there is efficient reflective ability for the UFH. Thanks for sharing that article, need to evaluate u-value differentials, but I do prefer maintaining breathability (potentially hindering some of the heat retention).

 

Breathability only becomes an issue when you use two non permeable materials to enclose a structure. Not an issue for Pir between joists. Differential shrinkage and contraction of the PIR and the timber is though and long term I fear you'll get gaps all around the insulation, no matter how careful you are installing it. I've heard reports of carefully fitted PIR boards dropping out after a few years.

 

If you are concerned about efficiency I think I would stay away from UFH in your situation. Rather get some large radiators and run them at a low temperature. For comfort stay away from  ceramic tiles, carpet vinyl wood or LVT is much warmer to touch.