ᐅ Aerated concrete or calcium silicate masonry with external wall insulation system (EWIS) using polystyrene foam
Created on: 26 Apr 2019 20:15
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Wugler1978
I’ll keep it short and simple. We are currently deciding between Ytong 36.5cm (14.4 inches) monolithic construction and sand-lime brick with an external thermal insulation composite system (ETICS) made of polystyrene, but we can’t decide which to choose.
Ytong is 11,000 euros more expensive, but we have a "bad feeling" about the insulation in the sand-lime brick option (use of pesticides, etc.).
What would you do and why?
Ytong is 11,000 euros more expensive, but we have a "bad feeling" about the insulation in the sand-lime brick option (use of pesticides, etc.).
What would you do and why?
Or in the render, if no paint is planned.
Mineral wool has the advantage of being perceived as more environmentally friendly. In multi-family buildings, (at least) fire barriers are required because EPS is flammable and drips like napalm. In single-family homes, this is usually irrelevant.
Compared to EPS, mineral wool adds more mass to the facade, which also improves sound insulation. According to some algae theorists, mineral wool stores thermal energy and does not cool down as quickly on the surface, meaning the reason for algae on EPS (surface dries more slowly, temperature drops quickly) is reduced.
My last external thermal insulation composite system (ETICS) facade cost a total of €23,000. It used 16cm (6 inches) EPS with a thermal conductivity of 0.032 W/mK in the Brillux system. Without paint, but with a “Protect” render containing protective additives. The house is about 200 sqm (including a flat roof with parapet). The additional cost for mineral wool would have been around €6,000. Besides the more expensive material, installation requires extra work for doweling. Mineral wool must not get wet, which poses its biggest risk, both during installation and afterwards (also for brick slip cladding).
Unlike EPS, mineral wool boards cannot be sanded. The risk of visible joints later on is higher. As far as I know, interlocking profiles (tongue and groove) are not available for mineral wool panels.
All in all: It can be done, but it comes at a price and is not without drawbacks. Even if EPS were to be found as the cause of the next chemical disaster, the price premium for mineral wool is in my opinion not justified. I have a neighbor who builds with filled Poroton bricks, which is very unusual around here, and accepts tens of thousands in extra costs for that reason—mainly because EPS has a somewhat bad reputation. But for the extra cost, he could have had the entire facade redone at least twice or repainted regularly for the next 50 years. Well.
Mineral wool has the advantage of being perceived as more environmentally friendly. In multi-family buildings, (at least) fire barriers are required because EPS is flammable and drips like napalm. In single-family homes, this is usually irrelevant.
Compared to EPS, mineral wool adds more mass to the facade, which also improves sound insulation. According to some algae theorists, mineral wool stores thermal energy and does not cool down as quickly on the surface, meaning the reason for algae on EPS (surface dries more slowly, temperature drops quickly) is reduced.
My last external thermal insulation composite system (ETICS) facade cost a total of €23,000. It used 16cm (6 inches) EPS with a thermal conductivity of 0.032 W/mK in the Brillux system. Without paint, but with a “Protect” render containing protective additives. The house is about 200 sqm (including a flat roof with parapet). The additional cost for mineral wool would have been around €6,000. Besides the more expensive material, installation requires extra work for doweling. Mineral wool must not get wet, which poses its biggest risk, both during installation and afterwards (also for brick slip cladding).
Unlike EPS, mineral wool boards cannot be sanded. The risk of visible joints later on is higher. As far as I know, interlocking profiles (tongue and groove) are not available for mineral wool panels.
All in all: It can be done, but it comes at a price and is not without drawbacks. Even if EPS were to be found as the cause of the next chemical disaster, the price premium for mineral wool is in my opinion not justified. I have a neighbor who builds with filled Poroton bricks, which is very unusual around here, and accepts tens of thousands in extra costs for that reason—mainly because EPS has a somewhat bad reputation. But for the extra cost, he could have had the entire facade redone at least twice or repainted regularly for the next 50 years. Well.
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Wugler19788 May 2019 15:33I hereby report completion!!!
We switched again from Ytong to calcium silicate blocks plus ETICS (external thermal insulation composite system) and saved €11,000. We can now spend that on other things, for example, a taller basement.
We switched again from Ytong to calcium silicate blocks plus ETICS (external thermal insulation composite system) and saved €11,000. We can now spend that on other things, for example, a taller basement.
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Wugler19788 May 2019 15:58CoolCat schrieb:
What is your wall structure there: 17.5cm (7 inches) calcium silicate brick, 20cm (8 inches) ETICS, and 2.5cm (1 inch) mesh and plaster?ExactlySimilar topics