The front door is designed to protect the home from intruders, from external noise, from cold street air, and extraneous odors. Some models of doors have heat-resistant properties, which will be useful in case of a fire outside.
What are the criteria for choosing communal entrance doors? Entrance metal doors are selected in accordance with the following parameters:
Where the door will be installed – in an apartment or a private house
That is, the door will communicate directly with the street, or not.
- Degree of protection. The presence of a peephole, intercom, surveillance camera; device and number of loops and locks; frame design; the number of stiffeners in the frame; the number of metal layers in the door leaf; metal thickness.
- Will a heater be used, what kind and its quantity. Insulation can be: cardboard, cotton wool, polystyrene foam, polyurethane foam.
- Door leaf weight.
- Door design.
- Availability of anti-vandal coating.
- The door frame can be with or without a threshold. More unreliable doors are produced without a threshold.
Steel for doors can be cold and hot rolled
When using cold-rolled sheet, the profiles are bent, which lightens the weight of the door, but at the same time increases its strength and durability. This would be the best option, but also more expensive.
If hot-rolled steel is used, then the structural elements are first cut and then welded together. This reduces the strength and reliability of the door.
The reliability of the door depends on the location and number of stiffeners. Stiffeners can be installed vertically, horizontally, diagonally, or combined. The more ribs, the more reliable the door, but its weight will also be greater. Ribs should be evenly distributed across the canvas.
Loops are internal (hidden) or external (open). Anti-removable crossbars are required for external hinges. They fix the door when it is closed.
If the door leaf is heavy, then support bearings are installed for the hinges – they support the door, facilitate opening / closing, and prevent creaking.
The hinges can be adjusted in height, there are hinges with a built-in lubrication mechanism. As a rule, these are quite expensive models.
To increase reliability, it is recommended to install two types of lock on the door – a cylinder and a cylinder design, this makes it difficult to break into.
There are locks with bolts retracting when closing, this does not leave criminals a chance to cut the lock.
Armored pads on locks can be used to prevent the lock from being shot.
Seals are made of polyurethane, plastic, foam rubber, silicone, rubber. They create an obstacle to the penetration of cold, odors, noise into housing. Reduce the noise when the door is closed. Rubber seals are the most reliable and durable. There are magnetic seals. If the door is fire-resistant, then in addition to the usual sealant, a thermoses is glued.
Mineral wool (for apartment doors), polystyrene foam, polyurethane foam (for private house doors), polyurethane foam, sound-absorbing materials serve as insulation in the door.
The outer coating must be resistant to weather, to damage by the claws of animals.
According to the security class, the doors are divided into:
- First grade. The most unreliable doors, with a small thickness of steel sheet. Easily cracked. Installed in rooms that do not contain valuables.
- Second class. Protection against hacking is somewhat more complicated.
Third class. To open such a door, you have to work hard and make some noise.
- Fourth grade. In the most secure doors, The level of protection is high. Locks with retractable bolts and armor plates are used in such models.
Fire resistant entrance doors
If the door is equipped with fire protection, then it should not melt, deform, should be resistant to high temperatures, open fire, should not let smoke and smell through.
Thus, when choosing an entrance metal door, it is necessary to clarify the requirements for its reliability, purpose, degree of convenience. You also need to decide on the price and external design.