Does creating a screw hole weaken the item with the hole? The simple answer is yes. Screw holes remove material from the item – which by definition reduces the material available to carry load through the structure. Does this cause any issues with greenhouse frames covered with rigid Solexx twin-wall plastic? The answer is absolutely not. In fact the frame/panel combination is significantly stronger than the frame was by itself. Any slight reduction in strength of the framing members is dramatically compensated by the shear strength and stiffness added by the Solexx panels to the greenhouse frame.

In fact, greenhouse construction is surprisingly similar to other stiffened panel construction used in house framing or modern aircraft. If you have ever put plywood sheathing on a wood framed building, you know firsthand that the structure increases in rigidity and strength the moment you start nailing plywood sheathing on the outside. This strength increases dramatically despite the small reduction of the stud strength by the holes created with the fasteners.

Yes, the fastener holes do slightly weaken the backup stringers but the combined strength of the panel and the stringer is much higher. Consider the following examples of stiffened panel construction and notice the similarity to greenhouses. Fasteners are a critical element in these structures to carry the shear load developed in the skin into the backup structure where it can be effectively distributed to the base of a building, the footings of a bridge, or the wings of an airplane.

For additional information and technical drawings, contact us at info@adapt8.us