The Door slab
is the the operating part of a door, it’s the part of a door which swings open and closed. On one side of the door there are hinges which connect the slab to the frame permanently, on the other side of the slab there is the hardware or handset. The door slab operates within a frame which fits the door exactly providing a continuous contact point around the entire perimeter of the slab.
Construction of the slab is critical to a high security door. The slab needs to have a strong internal framework, upon the framework there will be a skin which is the tactile surface of the door. A door slab frame and skin need to connect with each other in an extremely durable and dependable manner. It is common for the empty space between the skins of a door to be filled with insulation. The skins of a security door will be made of material which is resistant to impacts or penetration.
As mentioned before the slab of the door has hardware connected to it, hinges and the handset. The integration of the hinges into the door slab is critical for the security of the door. For example, the internal framework of the door slab should be connected directly to the hinges and handset. This provides for a continuity of the strength of material used. The idea that a chain is only as strong as its weakest link works here, and in the construction of a security door the link between the door frame and the hardware is just such a point of either strength or weakness.
On the other side of the door from the hinges is the handset which is manually operated.
can be very sophisticated and will only be examined lightly here. The handset is part of the hardware and it is manually operated by people. As with the hinges it is critical for the handset to be well connected with the framework of the slab. Additionally the connection with the door frame is critical. The handset – door frame connection is the most vulnerable part of a door.
Therefore particular emphasis needs to be put on this critical connection. Here is the reason why. All handsets will have some type of bolt or latch (sometimes called the “throw”) which retracts when the handset is operated. The idea being this, when the door is closed it is best to have a solid connection between the slab and frame. But to open the door the connection bolt or latch needs to be retracted into the door to allow the door to swing open.
This action of the bolt, for it to retract into the slab or extend out from the slab requires a number of moving parts, which is the achilles heal of the handset. Moving parts are always more difficult to secure than stationary parts. Moving parts need to operate together without fail and be able to withstand a lot of abuse. If this weren’t enough, the hardness of the materials themselves is another factor when considering the security of the door.
A window or “see-through” part in a door is called a LITE, people can see in and out of the door as well as light being able to pass through. The type of glass and the hardness of the glass in a door lite is essential for high security. Particularly, if the door has a large lite, sometimes called a FULL-LITE when it goes all the way from top to bottom, the glass makes up most of the slab. In this type of door design, which is typical for balcony or deck walkout doors, there needs to be specific engineering into the strength and impact resistance of the lite itself. And as you probably expected, the connect of the lite with the rest of the door slab is also very important.
the door frame serves two functions.
1. it holds the slab and connects with the slab when closed
2. It connects to the building envelope.