What does an interior doors unit include when you buy it?
The door is not only the door slab, but also the unit for the slab installation into the rough opening(door-frame, casings, extensions) and hardware, that ensures the door operation.
Door slab and hardware choice, in general, depends on taste and financial possibilities of the client.
The number of components is determined by the rough opening size.
In this article you will find out how to measure the rough opening and how many components you need. You can measure the rough opening yourselves, but we would recomment to call a builder to make the measurements.
This article is about standard and extra unit to have a common perception about necessary elements set when you buy an interior door.
Minimum interior door unit
Standard Belwooddoors unit includes:
- Door slab: it’s the core of the door in the shape of rectangle without jambs, hinges and casings;
- 5 or 2,5 casings on the both sides: it is represented by strikes that are installed around the perimeter (on the edges) of the rough opening on the both sides. It is used to mask the gaps between door-frame and rough opening;
- Jambs (door-frame girder): with the help of it the door is fixed into the rough opening: one strike/lath is in the right, the other is in the left and a half is for the upper(header).
It’s a minimum door unit.
A number of manufacturer add hardware, but it’s more like exception. In this case you need to buy hardware yourselves.
If desired, for some models, instead of the usual casing, you can order a plinth and mouldings: they are decorative elements in the horizontal upper and lower parts of the rough opening; the prototypes of antique decorations that adorned the columns;
Different elements can be included into the extended interior door complete unit.
The set depends on the characteristics of the room in which the interior doors will be installed, and on the type of doors.
It is one thing to install an ordinary single-slab door, and another thing to install a double-slab swing door. The necessary elements are bought on their own.

Standard Belwooddoors door unit
Standard unit includes the door slab, 5 casings and 2,5—3 jambs.
If desired, for some models, instead of the usual casing, you can order a plinth and mouldings: they are decorative elements in the horizontal upper and lower parts of the rough opening; the prototypes of antique decorations that adorned the columns;
Different elements can be included into the extended interior door complete unit.
The set depends on the characteristics of the room in which the interior doors will be installed, and on the type of doors.
It is one thing to install an ordinary single-slab door, and another thing to install a double-slab swing door. The necessary elements are bought on their own.
Belwooddoors Additional Door Unit
- The treshold is half of the jamb, it’s also the jumper at the bottom of the door-frame, closing the contour.
It’s installed if you want to maximize sound insulation or ensure compliance with the rules of fire safety.
The tresholds are also the main part of the bathroom door. - Extensions are extended plates, made from MDF with upper durability, that increase the size of the door-frame. Necessary if the rough opening is wider than the door frame.
The extensions use allows you to improve the look of the rough opening complex finish and prevent splitting of the door design composition/ Preserve the integrity of the door design composition - Flush bolt is placed in a two-slabs swing door to fix one of the slabs;
- Door closers. The mechanism, due to which the door closes automatically. It looks like a folding grasshopper leg. One end is attached to the door frame, the other to the door slab. As with hinges, it depends on them how smoothly the door closes.
- Astragal is a decorative vertical element, that need in order to conceal the gap in the two-slabs door (between two slabs). Usually made of veneered MDF and the same color as the main design;
- Hinges are fastening hardware with which the door slab is attached to the door-frame. It depends on them how smoothly the door will close. By design type, these elements can be plain, mortise, concealed;
- Set of door handles and locks — hardware, which is selected by color and style according to the general decoration of the door.
Other articles

Interior doors for small appartments

Interior sliding doors
The main rule of our cooperation is the provision of the most acceptable and beneficial terms for both parties, not only at the start of the partnership, but also
We provide you with a special and truly exceptional product - interior doors from the manufacturer.
The firm "BELWOODDOORS" provides each of its partners with constant assistance in the foundation of their business and will be happy to give the dealers such conditions:
- favorable pricing policy and accumulative bonuses;
- exceptional initial working conditions;
- advertising and information support;
- very large, all-time supported size door storage;
All without exception door leafs, which are presented in the catalog of our company, are made of excellent raw materials. They are very reliable. The doors can be supplied with accessories that include the most resistant types of locks with the newest closing system.
The firm "BELWOODDOORS" occupies favorable positions in the wholesale trade of doors throughout the country. We are ready to work on favorable terms for you and offer the widest choice of interior doors.
We are the manufacturer, therefore the prices at us are accessible. Our staff will always help you in choosing our products.