Not the Underground, but the Underdoor. The gap underneath the bottom of a door lets in sound, smoke, light, draughts, toxic gasses etc.

It is so easy to seal this gap with a dropseal that it is fitted to the bottom of the door and automatically drops down each time the door is closed (adjustable drop up to 25mm). The mechanical unit requires no electrical power to operate, and works on a hinge side plunger with flat spring mechanism that drops the neoprene gasket in a scissor like motion for a tight seal without any drag, even on an uneven floor. As the neoprene seal compresses, it forms a tight secure bond against the threshold or floor. The door seal retracts automatically when the door is opened.

Zero dropseals have been tested to five million cycles and are available surface mounted (for retrofit); semi morticed or fully morticed in three architectural finishes. The product is available in stock sizes from 305mm to 3497mm in 152mm increments, and may be cut down by up to 152mm from the non operating end to suit exact door widths. Units are not handed, and operate from one end only so they can be used on pairs of doors.

Special purpose dropseals are also available: with intumescent for fire doors, with light springing for disabled users, with lead lining for X-ray doors, and with carbon filled silicone rubber gasket to combat electromagnetic/radio frequency interference.

These units ensure an effective seal at the bottom of the door against air and smoke filtration, or penetration by sound, light, flames, toxic gasses, electromagnetic and radio interference or X-rays. Used in conjunction with other Zero frame seals they form part of a total door kit. There are sets for negative and positive pressures and other product combinations that can achieve acoustic ratings up to 53STC.

“Zero – when nothing else is good enough for long enough.”

For more information contact Ken Drake on 01785 282910.

Posted on 9th September 2000 at 12:00 am