A door that protects
and stays beautiful

RC2 is often a sensible baseline when confirmed burglar resistance is required. Whether it is mandatory is set by the project, the risk and the client's or insurer's requirements — not by a blanket rule.

No. Without data on the frame, lock, hinge side and installation, thickness does not prove burglar resistance.

A certified, convenient system that belongs to the tested configuration and allows safe exit from inside is better. The number of mechanisms alone does not answer the question.

Yes, if it is compatible. For an RC or fire door, check the permitted model, length, projection, class, protective rose and how the change affects the documentation.

Warning phrases:
— «armoured door» without RC;
— «EI30» without a classification document;
— «40 dB» without Rw and a test report;
— «class 4 lock» without naming the standard;
— «100 % frost-proof» without conditions;
— «three seals guarantee smoke control»;
— CE called a state quality certificate;
— door class inferred only from metal thickness.

Do not force it. Check:
— whether the lock works with the leaf open;
— whether the bolts align with the strike openings;
— whether the leaf has dropped;
— whether seal compression is excessive;
— whether the cylinder is dirty.

If the lock works easily with the leaf open, the problem is usually geometry or adjustment.

Assess the risk that the key can be identified and replace the cylinder or re-code the system if that is provided for. For an RC door, choose a compatible cylinder and keep the protective rose.

The latch holds the closed leaf and usually does not replace locking. Protection is determined by the lock and the whole doorset.

No. EI30 is confirmed by testing and classification of the complete doorset.

Sometimes yes, but you must check corridor width, adjacent doors, the project, escape routes and approvals. Do not create an obstruction in the shared area.

The general rule has exceptions. For an ordinary flat you cannot decide from a single phrase alone. Follow the project and do not worsen the escape route.

For an ordinary private flat usually not. Safe opening from inside matters. EN 179 or EN 1125 are chosen according to the exit purpose and the type of users.

Possibly. Check the project, the building's fire-resistance grade and the wall's function. Do not replace an existing EI door with an ordinary metal model.

It depends on the project and the certified configuration. For some apartment doors the rules provide exceptions, but a closer may still form part of a specific fire-door solution.

Not necessarily. Look at confirmed sound insulation, air permeability, smoke control, the threshold and the quality of adjustment.

It is usually not the main parameter for a warm, enclosed stairwell. For a cold lobby, an open gallery or a large temperature difference, the need is assessed on thermal grounds.

Ask for the Rw value and a document describing the configuration. Compare doors on the same indicator and allow for installation.

Possible causes:
— a gap under the door;
— poor seal compression;
— an incorrect installation joint;
— openings;
— flanking through the wall;
— no threshold;
— incorrect adjustment.

Possible causes:
— negative pressure in the flat;
— faulty ventilation;
— a leaky installation joint;
— a damaged seal;
— a gap under the door;
— open service penetrations.

Possible causes:
— a cold surface;
— high humidity in the flat;
— a cold stairwell;
— a cold bridge;
— incorrect door position in the wall;
— weak ventilation.

Yes, if the manufacturer provides for it. An unauthorised heavy adhesive mirror can overload the hinges and change special performance.

For an ordinary door — after checking the construction. For an RC, EI or smoke-control door the opening must be allowed by the documentation.

An ordinary door can be fitted if the manufacturer allows it and the instructions are followed. For an RC, EI, smoke-control or heavy door, qualified installation with documentation is preferred.

They work together. A strong door in a weak wall does not deliver the claimed protection. For RC, the substrate and fixing requirements matter.

For a proper metal entrance system the whole doorset is usually replaced. A new leaf in an arbitrary old frame does not confirm RC, EI or acoustic performance.

Yes. Mass, balance, fire behaviour and sometimes access to fixings change. For a special door use only approved panels and fixing methods.

On an ordinary door — with a compatible profile after checking sizes. On a smoke-control or fire door the seal is part of the confirmed system and arbitrary replacement is not allowed.

For an ordinary door this is not a universal legal duty. Qualified fitting still reduces the risk of errors. For special doors it is especially important to confirm competence and compliance with the instructions.