self build waterproof basement formwork membrane concrete kickers

No Kickers

Kickers leak and are Very Difficult to Repair

There are several simple alternatives

First, an explanation of problems with kickers.

This image is taken from the web site of a company that sell the hydrophylic tape you see on the top ....

Of a kicker still with laitance on the top,
With holes at the bottom
and clearly soaking up water like a sponge.

You won't have much success waterproofing concrete with kickers.

If a hydrophylic strip worked it should be under the kicker as well.

But hydrophylic strips often fail because the problem is voids in the concrete itself.
self build basement

kicker and tape

How might the workforce above have produced such poor concrete in their kicker?

This image is taken from the Grace Adprufe System BBA Certificate 06/4319.

The concrete is being segregated (bleeding) by the poker held still and obviously any concrete in the kicker is sinking into the slab.

kicker So the concreting gang will tend to leave the kicker empty or fill it later when the slab is setting.

With what is anyone's guess. I would say the same concrete set aside until it is stiff and setting itself and out of time is the most usual.

If you pokered 100mm high good, fresh concrete in a kicker hours after the slab was formed. Everyone would be splattered from head to toe and the kicker almost empty.

You cannot form a waterproof kicker, so kickers are banned if you want a waterproof structure.

You might think that if you get a guarantee with your waterproof concrete

For instance at an extra £80 or so a m³ from Cementaid for Caltite

Or an extra £1200 plus £40 or so a m³ from Pudlo (typical for self builders)

that they will come and repair your kickers for you.

Don't be silly. They aren't that daft.
cementaid caltite

cementaid caltite

Kickerless Formwork.

All these ways to avoid kickers are acceptable.

kickerless props kickerless kicker from ROM form bolted down fastform
These timber props are fixed to the slab and made of 4x2 that is eventually reused in the building, making it very cheap. Another kickerless kicker.
Others are available.
Doka from Mabey bolted down. FastForm. Also bolted down.

All kickerless formwork needs bracing to keep it upright since it cannot be clamped to a kicker.

If kickers have any structural benefit at all it is preventing grout loss. But expanding foam is even better. prevent grout loss

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