One option to protect the door and the threshold includes adding a canopy over the door. The canopy should broadly deflect water away from the door, the gaps around it, the threshold, and the jamb intersections. Canopies that are large compared to the height of the door can be effective, assuming they extend far enough to shelter the door, threshold, and exterior edge of the operator. In contrast, more modest canopies or designs with no canopies fail to protect doors and thresholds from wind-driven rain. If there is no canopy or a shallow canopy, wind-driven rain can strike the wall above the door, ultimately washing over the door and its threshold. Therefore, protecting the waterproofing at the threshold is vital.
Terminating waterproofing at doors with in-floor operators
Some designs try to keep all the waterproofing on the exterior edge of the operator, but the operator typically extends into the exterior space beyond the door. Terminating upturned waterproofing outside the building wall is an ill-advised practice without extensive precautions. Continuing waterproofing under the operator requires designing, installing multiple penetration details, and providing conditions that allow the operator to function by rotating a heavy glass door. Running waterproofing under the door operator is the better strategy, but the designer must first understand the operator and its requirements.
How in-floor door operators work
To effectively waterproof a threshold with an in-floor door operator, one must first understand how a door operator works. An in-floor door operator consists
of an electric motor that rotates a vertical axle at the hinge side of a door. The axle rotates when triggered by a switch or small opening force applied to the door. The bottom of the axle usually terminates within the operator’s housing, but some designs allow it to extend through the bottom of the housing. If the waterproofing is directly under the housing, wrapping waterproofing around a rotating axle is difficult, if not impossible.
Large doors require robust operator housing and electric motors not only to operate the door, but also to hold it in place when it is not operating. Operator design considers the use frequency and factors in weather exposure and wind resistance to prevent slamming. To open the door, the motor quickly applies torque to the door axle. An all-glass, full-size entrance door can weigh on the order of 453 kg (1,000 lbf). When the motor applies torque, the motor and housing need to react against a rigid anchor. Soft surroundings, such as thick waterproofing membranes or unintentionally flexible anchorages, cannot provide the rigidity these operator anchorages require.
As door operators are electrically powered, wiring is necessary. The waterproofing strategy discussed ahead involves putting the operator above the waterproofing. However, electrical power must penetrate the waterproofing to reach an operator above it.
Thanks for the well written and helpful article Dan and Matt
This article on waterproofing in-floor door operators is a must read for anyone involved in construction and waterproofing. The detailed steps and considerations it outlines ensure both the functionality and longevity of door operators in wet environments. It’s a valuable resource for professionals aiming to achieve robust waterproofing solutions.