I need some tips regarding a small extension I'm working on. Building 3x4m in two floors. The lower floor will be a slab on grade and Leca walls, the upper floor timber frame and wooden joists. I have a few questions about the Leca.
The extension is at a corner of the house, it will be one wall of 3m, one of 4m, and a small section connecting to the existing structure of about 1m. The basement floor will not be backfilled against (ground level). I don't have construction drawings since it's such a small simple structure.
My questions:
The basement is uninsulated and will never be able to be insulated due to its construction (built in 1907). The new basement room will also not be fully insulated, as it will be used as a workshop. But what thickness of Leca should I choose? 20 or 25cm?
How should I reinforce the walls? Is there something general that can be said?
Against the slab. Should I lay the first layer in mortar, or something else? Saw someone who laid a sill gasket underneath and claimed it bonded the Leca to the slab.
Should I mortar the vertical joints or is it okay to skip it?
Grateful for all the tips as I have never built with Leca before...
The extension is at a corner of the house, it will be one wall of 3m, one of 4m, and a small section connecting to the existing structure of about 1m. The basement floor will not be backfilled against (ground level). I don't have construction drawings since it's such a small simple structure.
My questions:
The basement is uninsulated and will never be able to be insulated due to its construction (built in 1907). The new basement room will also not be fully insulated, as it will be used as a workshop. But what thickness of Leca should I choose? 20 or 25cm?
How should I reinforce the walls? Is there something general that can be said?
Against the slab. Should I lay the first layer in mortar, or something else? Saw someone who laid a sill gasket underneath and claimed it bonded the Leca to the slab.
Should I mortar the vertical joints or is it okay to skip it?
Grateful for all the tips as I have never built with Leca before...
Can't claim to be an expert, but I recently built a similar structure to yours (in my case an extended entrance), measuring 3.5 x 2 m, slab on grade in the basement (10 cm thick, except at the edges where the footings are 20 cm thick). I chose to make the walls 25 cm (I never even considered 19 cm blocks, it feels too thin for a load-bearing basement wall). Used a sill board between the slab and the first course. This is not to "glue" the blocks to the slab, but rather to control any potential cracking; the wall and the slab can move slightly against each other without cracks forming. If there is significant soil pressure (deep basement and long walls), you must ensure that the wall cannot be pushed into the house, for example with an L-shaped iron at the angle between the floor and the wall (there are other ways too). I reinforced every other course with galvanized rebar, one in each "channel" in the lecablocks. I also mortared the vertical joints. In the top course, I also embedded some protruding threaded rods, which I can screw the sill into (it is also fastened with facade plugs).