Formwork plugs and cones: how to seal tie holes

2026-10-20

What cones, plugs and spacer tubes do, how they work together and what to consider when choosing them.

When pouring walls, formwork panels are tied with rods that pass through the concrete. Spacer tubes, cones and plugs let you remove the rods and seal the holes neatly.

Spacer tube and cone

The tube keeps the panels apart and protects the tie rod; cones at its ends fix the tube and form a clean hole entrance.

Plug

After stripping, the hole is closed with a plug that keeps moisture out and improves the surface finish.