Skip to Content


Importance of Interlocks

Usually a sliding security door will have a bottom pip or train-line type of track that is raised so as to locate the bottom rollers. This will normally not be in a U channel but in some instances it can be depending on the design of the door extrusion. There are many different types of extrusions in Australia with many companies adding their own special touch to the design; having said that, most will have top and bottom tracks to accommodate a sliding screen or sliding security door. Usually the top track will consist of a U channel that will be over 20mm in width and up to 20mm in depth, sometimes having an opposite pip track so as to locate the rollers in the door on the track. This will avoid any slip or movement in the top track so as to allow the lock to engage exactly where it is measured and designed to go without sideways movement.

Interlocks are a form of locking the door to the opposite side to the lock of a sliding security door. It is not necessary in the case of a sliding fly door as there is no need to lock the door on both sides given the nature of the door is not a security product. Having said this, there is frequently a receiving interlock on the fixed glass panel of most modern extrusions and it would make sense if this was in place to have the frame interlock included on the back of the sliding fly door as opposed to installing a bug seal as it will give a degree of certainty exactly where the door will stop, particularly with centre-opening French-style sliding fly doors.

Most modern extrusions will have a receiving interlock. This is usually located at the back or glass side of the fixed glass mullion aluminium section. It is designed to receive the frame interlock which will be located on the back of the sliding security or fly sliding door. If there is not a receiving interlock then one should seriously consider adopting a receiving interlock prior to measuring or installing one at the same time as you would install a sliding security screen door.

A receiving interlock will allow it to connect with the frame interlock that is located on the back of the sliding security screen door at the precise moment it is slid into the closed or locking position. This is a simultaneous action that is designed to lock the door on both sides without any additional actions required by the person closing the door. In other words, by closing the door it will effectively lock the door into the fixed glass panel on the opposite side to the lock automatically.

Interlocks are extremely important if any measure of security is required for your sliding security screen doors. The reason for this is so that the sliding door will lock on both sides and render it extremely difficult to remove and this will have the desired effect of the owner being able to leave their sliding glass door open to receive fresh air, all with a relatively high level of security, depending on the installation and type of sliding security screen door chosen. Both a receiving interlock with a well-fitted frame interlock on the back of a sliding screen door will engage together at the exact point the door is placed in the closed position, effectively stopping insects and making it more difficult for removal by unwanted guests. It will also minimise or eliminate the gaps completely between the door and the fixed glass panel.

When considering a Seconline sliding security door, if your needs are to have this as a measure of extra protection then you should always ensure that you install interlocks to the back of these doors.

Back to top