Screens and the insect-load market

The mesh, and what it trades

• Fibreglass mesh: the standard insect screen, low cost, good airflow, excludes insects. It does not resist force.
• Aluminium mesh: stronger, used where a screen takes more handling, at slightly less airflow.
• Stainless-steel mesh: the security grade, resists cutting and impact, at the most airflow loss and cost.
• The aperture and the wire set the airflow-and-exclusion trade, so the schedule names the mesh, not just a screen.

Fixed, roll-down or retractable

A fixed screen is the simplest and the cheapest, and it suits the window that stays closed to the insects and open to the air — the bedroom in a humid market. A roll-down or retractable screen clears the opening when the view matters and stores out of the way, at the cost of the mechanism and the track. The tropical market usually runs fixed on the small openings and a roll-down on the large, because the large opening is the one the room looks through.

Security mesh, where it is asked for

Where the market asks for intrusion resistance as well as insects, the stainless-steel security mesh replaces the insect mesh on the same frame, and the frame and fixings are upgraded to take the load of a forced attempt. The security case is specified as its own line, like the impact case on the glazing, because it changes the mesh, the frame and the fixing — a frame that carries security mesh is not the same frame as the insect screen.

What to put on the schedule

• The mesh type per opening: insect, aluminium or stainless security.
• The operation: fixed, roll-down or retractable, per the opening and the elevation.
• The frame and fixing, especially on the security grade, where the load is taken by the fixing.
• The screen as a line item with the window, so the frame arrives prepared for it rather than drilled on site.