ᐅ Basement needs to be warmer – underfloor heating, insulation?
Created on: 18 Mar 2018 16:13
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drakrochmaD
drakrochma18 Mar 2018 16:13Hello,
We have a Massa house prefab built in 1980.
On the ground floor and first floor, we replaced the windows and doors with triple-glazed units featuring 8 chambers, added around 16cm (6 inches) of insulation on the exterior, and also insulated the sloping ceilings in the living areas.
The previous owners/builders did a really poor job, sometimes installing the fiberglass insulation with gaps up to 10cm (4 inches), so it’s no surprise the heating couldn’t keep up.
With the new heating system (pellets + solar) and the measures mentioned above, the upper floors are now okay—or at least much improved. Unfortunately, the basement remains a problem.
The basement rooms have a ceiling height of only 2.10 - 2.20m (6 ft 11 in - 7 ft 3 in). The floor consists only of a concrete slab, screed, and poorly laid tiles. We had the exterior walls insulated down to about 50cm (20 inches) below ground level. Yes, that was a mistake; we should have insulated all the way down—something we’ll know for the next house [emoji4].
Our problem is that we have a fairly large party room in the basement, about 45sqm (485 sq ft), with only one radiator in the corner, and the floor is always cold. We would like to insulate and heat the floor. However, the ceiling height is already tight.
We insulated the basement ceiling (toward the living area above) with 8cm (3 inches) of mineral wool to hide the pipes (heating, water, electricity). This construction resulted in a loss of about 10cm (4 inches), leaving the room with just 2.10m (6 ft 11 in) in height.
The actual questions:
- How thick should the basement floor insulation be to keep the room efficiently warm?
- What are the disadvantages of roughly 4cm (1.5 inches) of insulation, then a hydronic (water-based) underfloor heating system, and a thin laminate floor above?
- How thick does the insulation below the underfloor heating need to be to be considered sufficient?
Would two layers of 1cm (0.4 inch) extruded polystyrene (Styrodur) plus a foil-backed insulating mat underneath be enough?
- What would be your recommendations?
Has anyone faced a similar issue and how was it solved?
Ideally, I would like to lift the house and add two rows of bricks underneath, but that doesn’t seem realistic. Therefore, I’m very interested in practical suggestions [emoji4].
Thank you in advance.
We have a Massa house prefab built in 1980.
On the ground floor and first floor, we replaced the windows and doors with triple-glazed units featuring 8 chambers, added around 16cm (6 inches) of insulation on the exterior, and also insulated the sloping ceilings in the living areas.
The previous owners/builders did a really poor job, sometimes installing the fiberglass insulation with gaps up to 10cm (4 inches), so it’s no surprise the heating couldn’t keep up.
With the new heating system (pellets + solar) and the measures mentioned above, the upper floors are now okay—or at least much improved. Unfortunately, the basement remains a problem.
The basement rooms have a ceiling height of only 2.10 - 2.20m (6 ft 11 in - 7 ft 3 in). The floor consists only of a concrete slab, screed, and poorly laid tiles. We had the exterior walls insulated down to about 50cm (20 inches) below ground level. Yes, that was a mistake; we should have insulated all the way down—something we’ll know for the next house [emoji4].
Our problem is that we have a fairly large party room in the basement, about 45sqm (485 sq ft), with only one radiator in the corner, and the floor is always cold. We would like to insulate and heat the floor. However, the ceiling height is already tight.
We insulated the basement ceiling (toward the living area above) with 8cm (3 inches) of mineral wool to hide the pipes (heating, water, electricity). This construction resulted in a loss of about 10cm (4 inches), leaving the room with just 2.10m (6 ft 11 in) in height.
The actual questions:
- How thick should the basement floor insulation be to keep the room efficiently warm?
- What are the disadvantages of roughly 4cm (1.5 inches) of insulation, then a hydronic (water-based) underfloor heating system, and a thin laminate floor above?
- How thick does the insulation below the underfloor heating need to be to be considered sufficient?
Would two layers of 1cm (0.4 inch) extruded polystyrene (Styrodur) plus a foil-backed insulating mat underneath be enough?
- What would be your recommendations?
Has anyone faced a similar issue and how was it solved?
Ideally, I would like to lift the house and add two rows of bricks underneath, but that doesn’t seem realistic. Therefore, I’m very interested in practical suggestions [emoji4].
Thank you in advance.
D
drakrochma19 Mar 2018 07:51Hello,
yes, I would be willing to knock it out.
We did the same in the hallway area.
Unfortunately, it didn’t help much.
The previous owners laid extremely thin wall tiles on the floor, with less than 1 cm (0.4 inches) of screed underneath.
Altogether, it was a maximum of about 1.5 cm (0.6 inches).
I don’t want to remove more, to avoid damaging the floor slab, especially since there is a stream about 15 m (50 feet) away and the groundwater level is relatively high.
A lot was done poorly with this cabin. I’m concerned that with the foundation slab, only the bare minimum was done.
By now, we have basically redone almost everything except the basement, including water, heating, and electrical systems in most of the house.
What we saw there...
Since the rest is new and in good condition, the basement stands out even more 🙂
yes, I would be willing to knock it out.
We did the same in the hallway area.
Unfortunately, it didn’t help much.
The previous owners laid extremely thin wall tiles on the floor, with less than 1 cm (0.4 inches) of screed underneath.
Altogether, it was a maximum of about 1.5 cm (0.6 inches).
I don’t want to remove more, to avoid damaging the floor slab, especially since there is a stream about 15 m (50 feet) away and the groundwater level is relatively high.
A lot was done poorly with this cabin. I’m concerned that with the foundation slab, only the bare minimum was done.
By now, we have basically redone almost everything except the basement, including water, heating, and electrical systems in most of the house.
What we saw there...
Since the rest is new and in good condition, the basement stands out even more 🙂
D
drakrochma19 Mar 2018 09:07Yes, I was thinking along these lines:
- Two layers of PUR rigid foam boards, each 2 cm (1 inch) thick, staggered.
- Thin-layer underfloor heating mats with studs.
- Thin laminate, vinyl, or something similar.
A few points are still unclear to me:
- What is used to cover these studded mats so that you can lay something on top?
- Is there anything thinner available?
- Is there a risk of moisture buildup underneath?
- Are 4 cm (1.5 inches) Styrodur boards sufficient for insulation against the concrete slab?
- Two layers of PUR rigid foam boards, each 2 cm (1 inch) thick, staggered.
- Thin-layer underfloor heating mats with studs.
- Thin laminate, vinyl, or something similar.
A few points are still unclear to me:
- What is used to cover these studded mats so that you can lay something on top?
- Is there anything thinner available?
- Is there a risk of moisture buildup underneath?
- Are 4 cm (1.5 inches) Styrodur boards sufficient for insulation against the concrete slab?
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