Betonnen statische zuiger Superior 1 lange rechte zijde, 3 afgeschuinde zijden

Superior static cowl in concrete with one long straight side and three chamfered sides, for a flue from 15 x 15 to 20 x 50 cm with another flue next to it. The straight side is vertical, so the cowl fits tight against the flue that runs alongside its long side.

The other three sides are chamfered and deflect rain and wind. On the straight side the external size is therefore smaller than on the version without a straight side. The build-up is the same as every Superior: a base ring, two profiled intermediate rings and an open crown with bird mesh and deflector, in natural grey concrete. The rings turn rising wind, side wind and downdraught into negative pressure above the flue outlet, so the draught stays stable and flue gases do not blow back. There are no moving parts and no power supply.

Each flue gets its own cowl. Order by the internal size of the flue and look up the matching type in the table.

Stack the rings dry and staggered on a clean, flat chimney top, so that the crown sits level.

Why is the external size not square on a square flue? Because one side is straight. Type 3A for a 20 x 20 cm flue measures 36 x 42 cm externally.

I have two flues side by side. Which version do I take? For each of the two flues a cowl with one straight side, with the straight sides against each other. A flue between two others needs two straight sides.

What is a tiratrek? A Flemish name for a static cowl, like bemalkap and bemal. It is also called an anti-downdraught cowl or chimney cowl.