ᐅ Insulation of crawl space between ground and ground floor slab
Created on: 23 Jan 2024 20:55
J
Janosch07J
Janosch0723 Jan 2024 20:55Hello everyone,
I have the following issue / building project:
- We live in a mid-terrace house, whose ground floor is about 50 cm (20 inches) above ground level (so it’s “partially basemented”).
- In front of this house, there is an extension built as follows: Two strip foundations that connect to the house (forming a “U” shape), on which a wooden extension was constructed (cross beams supporting wooden boards as the substructure for the floor).
- In the extension (which is open to the living area), we have underfloor heating covered with screed and tiles.
So we lose a significant amount of heat through the floor into the crawl space outside. We now want to insulate the crawl space afterwards. The question is: how?
- Which insulation material is best here? The height is a maximum of 25 cm (10 inches), so it’s not possible to crawl underneath. The area is approximately 3 x 2.5 m (10 x 8 feet), which makes laying boards impossible. Additionally, the insulation lies directly on the ground. The floor is dry (because it's covered), but there is always a risk that moisture could rise from the soil – so mineral wool is probably ruled out.
We considered using loose-fill insulation with perlite. However, due to the cross beams overhead, there are compartments at the ceiling level, and we are not sure whether we can fill these completely without gaps (2.5 m (8 feet) deep with 25 cm (10 inches) height makes controlled application very difficult).
My main questions are:
- Is perlite suitable for this? Or do you recommend another insulation material?
- Should I be concerned about potential mold growth (no ventilation under the wooden extension anymore)? Or is this not an issue with perlite?
Thank you very much in advance for your help and support.
Best regards
Janosch07
I have the following issue / building project:
- We live in a mid-terrace house, whose ground floor is about 50 cm (20 inches) above ground level (so it’s “partially basemented”).
- In front of this house, there is an extension built as follows: Two strip foundations that connect to the house (forming a “U” shape), on which a wooden extension was constructed (cross beams supporting wooden boards as the substructure for the floor).
- In the extension (which is open to the living area), we have underfloor heating covered with screed and tiles.
So we lose a significant amount of heat through the floor into the crawl space outside. We now want to insulate the crawl space afterwards. The question is: how?
- Which insulation material is best here? The height is a maximum of 25 cm (10 inches), so it’s not possible to crawl underneath. The area is approximately 3 x 2.5 m (10 x 8 feet), which makes laying boards impossible. Additionally, the insulation lies directly on the ground. The floor is dry (because it's covered), but there is always a risk that moisture could rise from the soil – so mineral wool is probably ruled out.
We considered using loose-fill insulation with perlite. However, due to the cross beams overhead, there are compartments at the ceiling level, and we are not sure whether we can fill these completely without gaps (2.5 m (8 feet) deep with 25 cm (10 inches) height makes controlled application very difficult).
My main questions are:
- Is perlite suitable for this? Or do you recommend another insulation material?
- Should I be concerned about potential mold growth (no ventilation under the wooden extension anymore)? Or is this not an issue with perlite?
Thank you very much in advance for your help and support.
Best regards
Janosch07