We plan to cut away part of the roof overhang and raise the exterior of the mexi facade up to the same level as the load-bearing inner wall made of lightweight concrete, by building up with leca blocks. We also plan to remove the wooden paneling on the gables and instead build all the way up to the ridge on the gables with leca. In addition, an angled extension of 15 sqm in leca is planned. After that, everything will be plastered.
Is it possible to mix materials in this way? What should be considered to avoid future cracks in the plaster? Should we instead build with mexisten instead of leca?
How should we proceed to avoid cracks in the plaster at the junction between the angled extension in leca and the mexisten on the house?
We do not want any joints; it is intended to be a uniformly plastered facade.
We will hire professional masons but need to know which materials work together.
Is it possible to mix materials in this way? What should be considered to avoid future cracks in the plaster? Should we instead build with mexisten instead of leca?
How should we proceed to avoid cracks in the plaster at the junction between the angled extension in leca and the mexisten on the house?
We do not want any joints; it is intended to be a uniformly plastered facade.
We will hire professional masons but need to know which materials work together.
Lecasten and Mexisten have approximately the same bulk density, so I don't think any load problem will arise. They are just half-brick walls without a load-bearing function. Lecasten is manufactured in Sweden, Mexisten is not anymore. It is important to choose the right type of mortar, especially at the transition from Mexi to Leca. Follow the manufacturers' instructions. Some stones need to be clamped on the gable. Everything you need to know about Lecasten can be found at weber.se. An alternative to Leca is lightweight concrete blocks. Unfortunately, these are no longer manufactured in Sweden either.
Many thanks! Do you have any tips regarding the plastering and what type of reinforcement is needed (mainly at the transitions but also on top of the Mexibrick) to avoid future cracks in the plaster? The Mexin is rough-hewn with deep pits, so it probably needs to be plastered once before the final plaster layer of Mexi+leca?
J justusandersson said:
The lecaternary walls on the gables should be reinforced in certain shifts. A special two-wire reinforcement is usually used. You'll find everything you need to know about handling the lecaternary on weber.se. Masonry with 12 cm thick lecaternary requires some practice for optimal results. The Mexistenen has properties that resemble lightweight concrete. It's important not to use a mortar that is too hard (cement-rich). The question is whether you really need to plaster the Mexistenen? If you fill the joints with a light mortar, you'll get a facade that has a plaster character with less effort. Then you can smooth plaster the lecaternary. My knowledge is quite general. There are many threads on Byggahus about these topics that you can search through.