Pleat your greenhouse
Here are some photographs of a small polythene greenhouse before
and after the application of valley cables.
This greenhouse doesn't pleat terribly well.
The cover was not properly tensioned originally resulting in
the pleats causing large deflections.
Also, the roof fabric has three corners to it in the path of
the cable where the force is concentrated.
The application of the cables increases the tension in
the fabric -and decreases its tendency to flap about.
However, it causes stress points, fabric creases and
makes pools in the creases likely to form.
The net effect is not very positive - but it made an