UFH - First Floor ideas...

[Nickfromwales]

 

 

 

 

 

 

🫡

 

The section with the clip rails screwed down was where the 300L UVC was to reside. I wanted some ‘connection’ there, prob only for my own sanity / reassurance, and nowt else.

 

I do enjoy doing stuff and getting zero complaints, so I’ll keep doing what I do because “if it ain’t broken……”. 

[Mulberry View]

11 minutes ago, Nickfromwales said:

Yup. Liquid Cemfloor screed straight onto that, 50-55mm thick, 60mm in 'places', job done.

 

The only issue for me is that I can't accommodate that thickness of screed. However, I could go for a "halfway house" with the Roth system and their fibre reinforced liquid leveller (or another similar product), which they rate at 17mm total system thickness, so it'll be a few mm thicker by getting rid of the plastic grids. That's obviously not 16mm pipe though.

[Nickfromwales]

1 minute ago, Mulberry View said:

 

The only issue for me is that I can't accommodate that thickness of screed. However, I could go for a "halfway house" with the Roth system and their fibre reinforced liquid leveller (or another similar product), which they rate at 17mm total system thickness, so it'll be a few mm thicker by getting rid of the plastic grids. That's obviously not 16mm pipe though.

Can a 10 or 12mm pipe be part of that 17mm thickness?

[Mulberry View]

Just now, Nickfromwales said:

Can a 10 or 12mm pipe be part of that 17mm thickness?

 

Yes, they prescribe 10.5mm pipe for 17mm total, or 16mm pipe for 25mm total.

 

I'd like to try to make the UFH/Screed/Microcement layer compatible with thick carpet/underlay in adjoining room, so figured that 21mm total would work well against underlay and carpet. We don't need loads of heat in there.

 

I also have a floor to ceiling window with only 50-55mm of frame to play with. The 10.5mm pipe solution gives me 41mm, the 16mm pipe would be 51mm.

[Nickfromwales]

Just now, Mulberry View said:

 

Yes, they prescribe 10.5mm pipe for 17mm total, or 16mm pipe for 25mm total.

 

I'd like to try to make the UFH/Screed/Microcement layer compatible with thick carpet/underlay in adjoining room, so figured that 21mm total would work well against underlay and carpet. We don't need loads of heat in there.

 

I also have a floor to ceiling window with only 50-55mm of frame to play with. The 10.5mm pipe solution gives me 41mm, the 16mm pipe would be 51mm.

You'll prob need next to feck all heat up there anyways, so go with the slimmer option.

[Mulberry View]

11 hours ago, Nickfromwales said:

You'll prob need next to feck all heat up there anyways, so go with the slimmer option.

 

Although I need to look more closely at the quote, they've based the whole-house design on 40w/m2. I'm guessing that 10.5mm pipe at 75mm spacing is similar output as 16mm pipe at 150mm spacing. You're right though, this is more to give a warm feeling to the floor and what little bit of heat input might be needed.

[SimonD]

8 minutes ago, Mulberry View said:

they've based the whole-house design on 40w/m2.

 

I hope the UFH design has not just been drawn up to a standard 40w/m across the whole house and has actually taken into consideration the room-by-room losses, designing according to those? Also 40W/m2 seems quite high to be for an energy efficient build.

[JohnMo]

9 minutes ago, SimonD said:

 

I hope the UFH design has not just been drawn up to a standard 40w/m across the whole house and has actually taken into consideration the room-by-room losses, designing according to those? Also 40W/m2 seems quite high to be for an energy efficient build.

You beat me to it. I'm closer to 15W/m2 output at -9. Sounds like cosy feet and melted body to me at 40W/m2. The 75mm spacing make my 300mm strange, I still only flow 28 degs max.

Edited May 22 by JohnMo

[SimonD]

5 minutes ago, JohnMo said:

You beat me to it. I'm closer to 15W/m2 output at -9. Sounds like cosy feet and melted body to me at 40W/m2. The 75mm spacing make my 300mm strange, I still only 28 degs max.

I recently completed a design on a 1930s retrofit with cellulose insulation added to the suspended timbers floors and the ground floor U-values in that are between 29-36W/m2. The whole house average is 36W/m2.

[Mulberry View]

10 minutes ago, SimonD said:

 

I hope the UFH design has not just been drawn up to a standard 40w/m across the whole house and has actually taken into consideration the room-by-room losses, designing according to those? Also 40W/m2 seems quite high to be for an energy efficient build.

 

In fairness, this is an outline quote, we're not at design stage yet so a set of heat loss calculations has not yet been done. I guess they'll charge for that in the end?

 

I'm trying to do that myself through Heatpunk, but it's tricky with my very irregular shaped house. I'm considering paying for the Pro level for a month or two so I can upload my plans! But that doesn't help with ceiling levels (I have sloped ceilings). I haven't added all the windows yet, but it looks like 21w/m2 on there at the minute.

[Mulberry View]

10 minutes ago, JohnMo said:

You beat me to it. I'm closer to 15W/m2 output at -9. Sounds like cosy feet and melted body to me at 40W/m2. The 75mm spacing make my 300mm strange, I still only flow 28 degs max.

 

I'm sure my proper UFH design will uncover that 40w/m2 is far too much. See my reply to @SimonD below. Thanks for your input, BH has been great to me, the support is helping me keep my head above the water (just about!).

[SimonD]

1 minute ago, Mulberry View said:

 

In fairness, this is an outline quote, we're not at design stage yet so a set of heat loss calculations has not yet been done. I guess they'll charge for that in the end?

 

I'm trying to do that myself through Heatpunk, but it's tricky with my very irregular shaped house. I'm considering paying for the Pro level for a month or two so I can upload my plans! But that doesn't help with ceiling levels (I have sloped ceilings). I haven't added all the windows yet, but it looks like 21w/m2 on there at the minute.

Well, perfect timing. If you pop over to the tool I've developed at https://openheatloss.com you can model irregular shaped rooms (by breaking the room into segments) and each segment can use single or double pitched ceilings - it's text based, so you don't have to try and draw it. It's also open source and free so no need to upgrade your subscription. 

[JohnMo]

Just download a trial copy of loopcad for doing UFH design. 

[Nickfromwales]

14 hours ago, Mulberry View said:

so it'll be a few mm thicker by getting rid of the plastic grids

Yup. Bin those off, as a box of 10mm nail clips is change of a tenner   

[saveasteading]

Now have a sample of what we are using. It's available with a thin eps underlay which we will not have.

We will instead lay an acoustic dampening sheet.

So we are left with an 18mm tray. The pipes clip into that and then we have a screed designed to be 30mm thick.

We need that because there is a balcony sliding door setting a low datum.

 

With what should we glue the Acoustic foam down? I'd rather find a tube mastic than tape, for ease.

 

Then ditto the plastic grid  I had been thinking screws into the chipboard floor...it feels solid and certain.

But perhaps first a glue for speed and overall adhesion.

Any advice on good tube adhesive that doesn't melt plastic?

[Mulberry View]

39 minutes ago, saveasteading said:

Now have a sample of what we are using. It's available with a thin eps underlay which we will not have.

We will instead lay an acoustic dampening sheet.

So we are left with an 18mm tray. The pipes clip into that and then we have a screed designed to be 30mm thick.

We need that because there is a balcony sliding door setting a low datum.

 

With what should we glue the Acoustic foam down? I'd rather find a tube mastic than tape, for ease.

 

Then ditto the plastic grid  I had been thinking screws into the chipboard floor...it feels solid and certain.

But perhaps first a glue for speed and overall adhesion.

Any advice on good tube adhesive that doesn't melt plastic?

 

I recommend Soudal Fix All, I've used it on EPS with no issues. Sticks EPS to other surfaces really well. An easily available one if you don't want to think too much about it.

 

https://www.screwfix.com/p/soudal-fix-all-high-tack-hybrid-polymer-adhesive-white-290ml/64585?gclsrc=aw.ds&gad_source=1&gad_campaignid=895557794&gbraid=0AAAAAD8IdPxQZcwfDg7XuWT6M7XU5qJW_&gclid=CjwKCAjw8uTQBhAdEiwAVvtJytd5T8metMhSfttfGiRHNorqe-zWY_O6Zos9P_4E07LqWha0FGRpwRoCSywQAvD_BwE

 

Other options are Illbruck SP350..

 

https://www.dortechdirect.co.uk/catalog/product/view/id/742.html?gad_source=1&gad_campaignid=17178602520&gbraid=0AAAAADt-Kn0ph4eAt3inbtCk9Tjt8IA77&gclid=CjwKCAjw8uTQBhAdEiwAVvtJyrHurwMiX1eVezExj4zWyNFuYLzJ_LObPlYyH2qK77MUmOXTMa0tLBoCF0gQAvD_BwE

 

But it was quite thick when I used it earlier in the year, so I'd suggest warming the tubes first....

 

Or this stuff if you can weigh it down whilst it cures as it is low expansion, but has been good at stick EPS to concrete etc.

 

https://ewistore.co.uk/shop/external-wall-insulation/eps-adhesive-ewi-240-750ml/

[Mulberry View]

43 minutes ago, saveasteading said:

Now have a sample of what we are using. It's available with a thin eps underlay which we will not have.

We will instead lay an acoustic dampening sheet.

So we are left with an 18mm tray. The pipes clip into that and then we have a screed designed to be 30mm thick.

We need that because there is a balcony sliding door setting a low datum.

 

With what should we glue the Acoustic foam down? I'd rather find a tube mastic than tape, for ease.

 

Then ditto the plastic grid  I had been thinking screws into the chipboard floor...it feels solid and certain.

But perhaps first a glue for speed and overall adhesion.

Any advice on good tube adhesive that doesn't melt plastic?

 

I'm guided by a low datum too. My bathroom window is floor-to-ceiling and with a  50mm frame height, so my total is 40-45mm in reality to include a structural layer. Damn I wish I hadn't got rid of the frame packer under it, but in all fairness, 45mm does work well with adjoining rooms anyway as I'm going from Microcement in the bathroom to thick carpet in the bedroom.