Hello,
My wife and I are planning to build a 1.5-story house. We would like to have a plastered facade and understand that it is technically best to have a frame made of lightweight concrete or concrete. We have taken a liking to leca isoblock 2.0 35, which are leca blocks with built-in insulation, see link below. The U-value according to the producer is 0.13 W/m2. We have sought a lot of information but would like some input from you here on the forum:
https://www.se.weber/files/se/2018-11/leca-isoblock-2.0-35.pdf
1. Price - We have received a quote for the material, but what is the actual cost of the work itself? Does anyone have approximately the price for the actual masonry of leca blocks per m2? And what is the equivalent price for external and internal plastering? We are thinking of a geometrically relatively simple L-shaped house. We think blocks with built-in insulation at least reduce the number of work phases, but it might still end up being significantly more expensive than working with a wood frame and the associated facade?
2. Energy - Are these leca blocks competitive with wood frames + insulation when it comes to the energy aspect? We have no goal of passive houses or similar but do not want to have excessively high energy costs. We understand that the wall will be quite thick, but we can live with that. We think the risk of cold bridges is reduced with leca blocks and that the specific heat capacity is higher, which should improve the indoor climate and reduce energy costs?
3. Moisture - We believe that leca blocks with external and internal plaster are completely safe against moisture if done correctly since the material is inorganic. Does anyone disagree with this?
4. Other comments - Has anyone built with leca blocks before and have any other important insights? Advantages/disadvantages?
Have a great Saturday evening!
/Filiph
My wife and I are planning to build a 1.5-story house. We would like to have a plastered facade and understand that it is technically best to have a frame made of lightweight concrete or concrete. We have taken a liking to leca isoblock 2.0 35, which are leca blocks with built-in insulation, see link below. The U-value according to the producer is 0.13 W/m2. We have sought a lot of information but would like some input from you here on the forum:
https://www.se.weber/files/se/2018-11/leca-isoblock-2.0-35.pdf
1. Price - We have received a quote for the material, but what is the actual cost of the work itself? Does anyone have approximately the price for the actual masonry of leca blocks per m2? And what is the equivalent price for external and internal plastering? We are thinking of a geometrically relatively simple L-shaped house. We think blocks with built-in insulation at least reduce the number of work phases, but it might still end up being significantly more expensive than working with a wood frame and the associated facade?
2. Energy - Are these leca blocks competitive with wood frames + insulation when it comes to the energy aspect? We have no goal of passive houses or similar but do not want to have excessively high energy costs. We understand that the wall will be quite thick, but we can live with that. We think the risk of cold bridges is reduced with leca blocks and that the specific heat capacity is higher, which should improve the indoor climate and reduce energy costs?
3. Moisture - We believe that leca blocks with external and internal plaster are completely safe against moisture if done correctly since the material is inorganic. Does anyone disagree with this?
4. Other comments - Has anyone built with leca blocks before and have any other important insights? Advantages/disadvantages?
Have a great Saturday evening!
/Filiph
2. A structure with higher thermal capacity results in lower energy consumption than one with lower thermal capacity with the same u-value.
3. Not true, it cannot mold. However, the structure can still become damp, and this moisture can be transported to other organic materials if you have them, and the plaster can be damaged.
3. Not true, it cannot mold. However, the structure can still become damp, and this moisture can be transported to other organic materials if you have them, and the plaster can be damaged.
Know-It-All
· Västra Götaland
· 12 296 posts
Well, the matter of heat capacity and energy consumption is not entirely simple. Generally speaking, it is primarily the U-value that matters. Higher heat capacity is, of course, an advantage because it provides a more stable temperature throughout the day and there may be less need for heating during cold snaps. The U-value is still what determines the energy loss through the building envelope.
Regarding thermal bridges, bear in mind that there will be a thermal bridge at the joint between each masonry block, although I don't know how large these are, unfortunately. Iso leca is a smart block, but you could just as easily build two thin leca walls with foam insulation in between; I wonder which would be cheaper in the end. The U-value of the blocks you are looking at is still quite okay.
Keep in mind that plastered walls indoors create a hard surface and a lot of echo, which can result in problematic room acoustics.
Regarding thermal bridges, bear in mind that there will be a thermal bridge at the joint between each masonry block, although I don't know how large these are, unfortunately. Iso leca is a smart block, but you could just as easily build two thin leca walls with foam insulation in between; I wonder which would be cheaper in the end. The U-value of the blocks you are looking at is still quite okay.
Keep in mind that plastered walls indoors create a hard surface and a lot of echo, which can result in problematic room acoustics.
Old thread but I still want to point out that plastered walls actually provide poor acoustics.