Hello everyone,
I have been puzzling over our floor construction for weeks and wanted to ask around...
We have an old house built in 1966 and are now planning a complete renovation, including new underfloor heating on the ground floor, first floor, and attic. There is also a basement, but it is not heated.
The existing floor structure is quite simple, with insulation, screed, and covering adding up to only about 6.0 - 6.5cm (2.4 - 2.6 inches).
My initial plan was to remove everything and then install a floating screed along with 16mm (5/8 inch) underfloor heating pipes on a proper insulation layer.
After consulting various screed installers, I’m more confused than ever, as everyone recommends something different...
One suggests using Schlüter dimpled plates, since they only require 0.8cm (0.3 inch) of pipe covering, but I then saw that the plates alone are already 4.4cm (1.7 inches) thick, so that brings me to at least 5.2cm (2 inches). Adding some extra for pipe covering, I estimate about 5.5cm (2.2 inches) plus around 2cm (0.8 inch) insulation, totaling about 7.5cm (3 inches) plus the floor covering.
Another proposes a solution with Retanol additives, allowing pipe covering to be reduced to about 2.5 - 3.0cm (1 - 1.2 inches), resulting in about 4.5cm (1.8 inches) with pipes plus insulation, totaling 6.5cm (2.6 inches) before the floor covering. That sounds promising, but it is probably quite expensive; no price has been given yet...
A third option is to leave out the insulation completely and build in a conventional way, with a total height of about 6.5cm (2.6 inches) plus covering.
Does anyone have advice on whether to use cement-based screed or calcium sulfate screed? I know cement screed works for wet rooms and outdoors, whereas calcium sulfate conducts heat better but should not get wet. What about the Retanol additives—are they only compatible with cement screeds?
Also, what do you think about 2cm (0.8 inch) of thermal insulation? Is it enough to make a difference? What classification or product would you recommend? Or would it be better to leave out the insulation completely? Alternatively, insulating from below at the basement ceiling—is that worthwhile? The basement ceiling height is almost 2.2m (7.2 feet).
I hope I’ve included as much information as possible for now. I’m happy to answer further questions if needed.
I’d be grateful for any advice!
Best regards
I have been puzzling over our floor construction for weeks and wanted to ask around...
We have an old house built in 1966 and are now planning a complete renovation, including new underfloor heating on the ground floor, first floor, and attic. There is also a basement, but it is not heated.
The existing floor structure is quite simple, with insulation, screed, and covering adding up to only about 6.0 - 6.5cm (2.4 - 2.6 inches).
My initial plan was to remove everything and then install a floating screed along with 16mm (5/8 inch) underfloor heating pipes on a proper insulation layer.
After consulting various screed installers, I’m more confused than ever, as everyone recommends something different...
One suggests using Schlüter dimpled plates, since they only require 0.8cm (0.3 inch) of pipe covering, but I then saw that the plates alone are already 4.4cm (1.7 inches) thick, so that brings me to at least 5.2cm (2 inches). Adding some extra for pipe covering, I estimate about 5.5cm (2.2 inches) plus around 2cm (0.8 inch) insulation, totaling about 7.5cm (3 inches) plus the floor covering.
Another proposes a solution with Retanol additives, allowing pipe covering to be reduced to about 2.5 - 3.0cm (1 - 1.2 inches), resulting in about 4.5cm (1.8 inches) with pipes plus insulation, totaling 6.5cm (2.6 inches) before the floor covering. That sounds promising, but it is probably quite expensive; no price has been given yet...
A third option is to leave out the insulation completely and build in a conventional way, with a total height of about 6.5cm (2.6 inches) plus covering.
Does anyone have advice on whether to use cement-based screed or calcium sulfate screed? I know cement screed works for wet rooms and outdoors, whereas calcium sulfate conducts heat better but should not get wet. What about the Retanol additives—are they only compatible with cement screeds?
Also, what do you think about 2cm (0.8 inch) of thermal insulation? Is it enough to make a difference? What classification or product would you recommend? Or would it be better to leave out the insulation completely? Alternatively, insulating from below at the basement ceiling—is that worthwhile? The basement ceiling height is almost 2.2m (7.2 feet).
I hope I’ve included as much information as possible for now. I’m happy to answer further questions if needed.
I’d be grateful for any advice!
Best regards
N
nordanney19 Jun 2024 13:03Harakiri schrieb:
I think that with 2cm (1 inch) PIR/PUR insulation, which is aluminum-coated, using staples might be a bit tight. No, that works well. Not just a guess—I recently did 120sqm (1,292 sqft) myself. There are special extra-short staple pins for that.
Harakiri schrieb:
But if the ground floor and top floor are within the same “climate zone” concerning underfloor heating, then it’s not necessary to install expensive PUR insulation upstairs—you don’t really need insulation there if the rooms are fairly evenly climate-controlled. Exactly. PUR downstairs towards the basement, and upstairs whatever works best at 20mm (3/4 inch) for impact sound insulation.