Hello!
I am going to build a small basement that will serve as a foundation for a conservatory adjacent to my new vacation home. The basement will be built with lightweight aggregate blocks 19x19x59cm on a cast slab. The size is approximately 7.5x2.5x1.6m (LxWxH), i.e., 12x4x8 blocks.
I have read the documents available at Maxit and Finnja, and searched a lot of threads on this forum, but I still have a few questions before I begin, which I hope someone can help me with:
1. Sliding layer. It seems there are as many people who think you can skip the sliding layer as there are those who think it is necessary. Therefore, I thought I would skip it and build directly on the slab. Is that OK?
2. Anchoring to the slab. Do I need to anchor the first row to the slab in any way (besides mortar of course since I'm skipping the sliding layer)? There are many suggestions there, drill rebar into the slab to which the blocks are attached, groove a "ditch" for the first row, cast a ledge around it, cast an "inner sole" after building, etc.
3. Pillars. The main building stands on pillars, three of which are on the same slab that the basement will be built on. Should I build the wall directly against the pillars, or is it better to leave a space between the pillar and wall (and thus also between the house wall and the basement wall, if you understand what I mean...)?
4. Floor structure. On top of the basement wall, I plan to cast a concrete floor structure. Again, there seem to be different schools of thought; my idea was to build a mold and cast directly on the top, so the floor rests on and is cast into the lightweight aggregate wall. Is that a good idea, or should there be a sliding layer, etc., between the floor and the wall? I originally planned to use composite decking for the casting, and then the manufacturer recommends casting directly on the wall; it should be the same principle if you build your own mold, right?
5. Floor structure again. I haven't used a structural engineer for strength calculations, but from what I have calculated and read myself, it seems to be quite over-dimensioned if I cast a 10cm floor with rebar at the bottom and reinforcement mesh in the middle. Since the free span is only about 2.20, that should be enough, right? Or do you think I should hire an engineer for the calculation...
I would be very grateful for help with this!
Best regards,
Fredrik Thunved
