Formwork blocks on the foundation slab in a mortar bed or not?

Hello everyone, I have a base slab and now want to start building with 24 cm concrete formwork blocks on it. (It will be a pool). Do I now lay the first row of formwork blocks in a mortar bed and align them in it, or do I simply align the blocks "dry" and then concretize the first two rows directly, e.g., with concrete and reinforcement? Does that make a difference? Thanks for your answers.

Hi,

first measure how big the height difference of the base slab is. This measurement plus 0.5 cm will then be the thickness of your mortar bed. Of course, mortar goes underneath, otherwise you won’t be able to align the formwork blocks. The more precise you work on the first row, the more relaxed it will be afterwards. Ideally, if everything fits and the formwork blocks are very dimensionally accurate, everything else afterwards is like building with Lego.

okay thanks for the answer.

It could have been that it is also sufficient if I simply place and align the first row so that it fits and then directly fill it with concrete

Hello abc12345

of course it is sufficient if you place the formwork blocks on the board level. But it won’t be quite that simple. I do it this way; measure the height difference with the spirit level. Place the first formwork block on the level (plastic wedges will help you with this) and the next formwork blocks next to it. All on the level. Then mix mortar and press it under the formwork blocks. This stabilizes the blocks more than the unstable wedges. Since I can’t do masonry, I manage this way. It always works.

Steven

The formwork blocks that I have always used are unfortunately (verschiedene Hersteller getestet) not dimensionally accurate. Therefore, it hardly matters how precisely your blocks are aligned horizontally since it will not fit anymore after the third row at the latest. That is why I form the last few centimeters (usually about 3-5 cm) exactly and thus achieve my precise measurement to the millimeter.

) not dimensionally accurate.

Hello

therefore level each row with these plastic wedges.

Steven