ᐅ Concrete Formwork – How Is It Done Correctly?

I want to cast a ring beam on a sand-lime brick wall and am uncertain about how to proceed with the concrete formwork. Is it sufficient to dampen the wood beforehand, or should it be primed with release agent or form oil?

I’m bringing up this topic because other users might have the same question.

For my concrete formwork, I used wood panels called formwork panels. Particle boards are not suitable because they absorb too much moisture. Before pouring the concrete, I coated the formwork with formwork oil.

This makes it easier to strip the formwork later, and the concrete does not stick.

Materials for Concrete Formwork Non-absorbent materials that can be treated with a release agent are suitable for concrete formwork. Examples include formwork panels made of wood (commonly used on construction sites; usually yellow), coated wood boards, acrylic glass (plexiglass), PVC panels, expanded polystyrene (Styrofoam) panels, extruded polystyrene (Styrodur) panels, and similar. Absorbent materials are NOT suitable for concrete formwork, especially uncoated chipboard, MDF boards, or materials that lose a significant amount of their strength due to water absorption, such as cardboard. Aluminum sheets are strictly forbidden for concrete formwork because a strong chemical reaction occurs between wet concrete and aluminum, causing blistering.

Exactly, aluminum should not be used as concrete formwork. I use these formwork panels, which can also be easily cut with a circular saw. Before pouring the concrete, the formwork panels are coated with form oil. I use a broom for this. It works quite well.

For the ring beam, I simply used wooden boards. They were treated with oil beforehand, which made it easy to remove them after the concrete was poured.

I purchased formwork panels directly. I also lend them to friends and family. To ensure durability, the formwork is oiled before each use. Special formwork oil is used for this purpose. After the concrete work is done, the formwork is dismantled and thoroughly cleaned. Then it is oiled again.