Category Archives: Doors

Flushing door/Flush door – Types and applications

Flushing door or flush doors are internal doors with a basic and elegant form, a level surface, and minimum decoration. The door panels are flush with the frame, hence the name “flush door.” Flush doors are popular in modern architectural design because of their clean, minimalist appearance and adaptability.

Doors obstruct or provide access to an entrance or exit to a building, room, or vehicle. Doors are essential for providing security and privacy. They can be made of various materials, including wood, metal, glass, or composites. They come in different forms. Doors are outfitted with a range of hardware such as locks, handles, hinges, and closers. This is to limit access and facilitate smooth operation. The type of door and hardware used depends on the intended purpose and location. For example, residential doors are typically more aesthetically pleasing, while commercial doors prioritize functionality and durability. Doors are essential in building construction and architecture because they can contribute to the overall aesthetics of a room.

This article is about Flush doors and types of flush doors used in building construction and architecture.

What is a flushing door or flush door?

A flush door is an interior door with a smooth, flat surface and no decoration or raised panels. The door panels are flush with the frame, giving the door its name. These doors have a wooden frame with plywood, MDF, or natural wood fixed on both sides. The top surface is finished with laminated sheets, veneers, paint, etc., resulting in a standardized and straightforward appearance. Flush doors are commonly constructed using wood in residential buildings due to their attractive and rich appearance. Poplar, mango, or pine wood can be used to construct the doors.

Flushing doors

Different types of flushing doors

Flush doors are classified into different types. Classification is based on the materials used, the manufacturing method, the finish, and the location of the application.

The following are a few examples of common flush door designs:

  • Solid Core Flush Doors
  • Hollow Core Flush Doors
  • Cellular core flush door
  • Fire-rated flush door
  • Louvered flush door
  • Acoustic flush door

Let us discuss different types of flush doors in detail

Solid Core flushing/flush Doors

The manufacturers sandwich a solid core between two thin sheets of plywood or MDF. The core is made of particleboard, MDF, or solid wood. This construction provides a flush surface on both sides of the door. They then veneer the door with real wood or decorative laminate. These doors typically consist of robust and mineral-based timber and use a variety of materials. The materials they use include blockboard, laminated core, cross band, face wood veneer, and particle board.

This construction method improves the door’s durability and resistance to damage compared to a hollow core door. Solid-core flush doors find frequent use in both residential and commercial structures. This is because of their excellent sound insulation and privacy features.

Solid core flush door

Solid-core flush doors are popular due to their customization options and affordability compared to solid wood doors. Solid core flush doors come in various sizes and styles, including panel and slab options. They can also be purchased with a range of hardware options, including hinges, handles, and locks.

Cellular core flush door

The cellular core flush door comprises a hollow core made up of a honeycomb or grid-like structure. The core is then sandwiched between two thin sheets of plywood or MDF. This creates a flush surface on both sides of the door. This construction method creates a lightweight and cost-effective door that is still relatively sturdy and durable.

The core of cellular core flush doors generally consists of a honeycomb or grid-like structure. The materials used to construct the core include cardboard or engineered wood, such as particleboard, MDF, or plywood. This structure creates a strong, yet lightweight core. The core provides some insulation and sound dampening, although not as much as a solid core door.

Cellular core flush door

Cellular core flush doors are popular in residential and commercial buildings. This is because they are relatively affordable, lightweight, and easy to install. Manufacturers offer a variety of sizes and styles for cellular core flush doors, such as panel and slab designs. Additionally, these doors are painted or stained to match any interior decor.

Doors made with this construction method may not offer the same level of durability or sound insulation as solid-core flush doors. This makes them more susceptible to damage from impacts or moisture. As a result, they are mainly used for interior residential doors rather than high-traffic commercial or industrial settings.

Hollow core flush door

Two thin sheets of plywood or MDF sandwich a lattice or grid-like structure to create a flush surface on both sides of hollow core flush doors, which are a type of interior door with a hollow core. The hollow core makes the door lightweight and easy to handle. This makes them a popular choice for interior doors in residential and commercial settings.

Hollow core flush doors are relatively affordable, and they are available in a variety of sizes and styles, including panel and slab designs. They are also easy to install, and they can be painted or stained to match any interior decor.

While hollow-core flush doors are lightweight and affordable, they do have some limitations. They are not as durable or sound-insulating as solid core or cellular core flush doors. The hollow core can also make them more prone to damage from impacts or moisture. Hollow core flush doors have a lattice or grid-like structure sandwiched between thin plywood or MDF sheets, making them best suited for interior use where sound insulation and durability are not a significant concern.

Fire-rated flush Door

Fire-rated flushing/flush doors withstand fire and smoke for a certain period of time. People typically use them in commercial or public buildings, as well as in multi-family residential buildings where building codes require their installation in areas that require fire resistance.

Manufacturers typically make fire-rated flush doors from fire-resistant materials, including metal, gypsum, or solid core materials like particleboard, MDF, or timber. The doors are often filled with fire-resistant materials Further they are covered with a layer of fire-resistant material, such as sheet metal, gypsum, or special fire-resistant paint.

Fire rated flush door

The rating of a fire-rated flushing door is determined by the length of time it can withstand a fire before it begins to fail. Fire ratings typically range from 20 minutes to 3 hours or more, and the required rating will depend on the building code and the specific application.

Fire-rated flushing doors may also have additional features, such as intumescent strips around the edges or fire-resistant glazing, to help contain fire and smoke. These doors can also be equipped with special hardware, such as self-closing hinges and automatic door closers, to help ensure that the door remains closed during a fire.

Ensuring the correct installation of fire-rated flush doors in accordance with local building codes is crucial to guarantee the required level of protection in case of a fire.

Louvered Flushing Door

A louvred flushing door is a type of interior door that has a series of horizontal slats or louvres inserted into the door panel. The manufacturers can make the louvres from wood, glass, or metal, and they usually fix them in place. However, some designs may permit adjustable louvres.

Louvred flush doors find their usage in areas that require air circulation or ventilation, such as utility rooms or closets. They can also be used in rooms that need privacy or light control, such as bathrooms or bedrooms.

The design of a louvred flush door can vary widely, from traditional styles with solid wood louvres to more modern designs that incorporate metal or glass louvres. They are also available in a variety of sizes and configurations, including single or double doors, and with different hardware options, such as hinges and handles.

Louvered Flushing Door

Manufacturers can make louvred flush doors from various materials, such as wood, MDF, or metal, and they can paint or stain them to match any interior decor. They can also paint or finish the louvres in different colours or textures to add an extra design element to the door.

Overall, louvred flush doors provide a unique combination of ventilation, privacy, and design that make them a popular choice for a variety of applications in residential and commercial buildings.

Acoustic flushing door

People often use acoustic flush doors in commercial settings such as recording studios, theatres, and conference rooms where privacy and sound isolation are important. The manufacturer selects materials with soundproofing properties to construct an acoustic flush door, and they usually build it with a solid core that dampens sound waves.

The name “flush” door comes from its design, which allows it to fit within the plane of the surrounding wall, creating a smooth and seamless surface when closed. This helps to prevent sound from leaking through gaps around the edges of the door.

People often use acoustic flush doors in commercial settings, such as recording studios, theatres, and conference rooms, where they require privacy and sound isolation. Homeowners can also use acoustic flush doors in residential settings, particularly in homes with open floor plans or in rooms where noise levels need to be controlled, such as home theatres or bedrooms.

When selecting an acoustic flush door, it is essential to consider factors such as the sound transmission class (STC) rating, which indicates the door’s ability to block sound, as well as the material used for the door’s core and surface. Proper installation and sealing of the door are also crucial for optimal soundproofing performance.

Types of doors – Top 7 door types explained

Types of doors commonly used in residential, commercial, and industrial construction depend on the application area, durability required, the purpose of the door, etc.

What is a door?

A door is a movable barrier or mechanism for opening and closing an entranceway or a building/room. The purpose of the door in this urban environment is security and privacy. Apart from security, safety, and privacy, an aspect of art, beauty, and elegance is associated with it. The entrance door acts as a warm welcome to the areas inside.

This article is about the types of doors popularly used in civil construction.

  1. Classification of doors in Civil Engineering
    1. Types of doors in civil engineering– location based
      1. Exterior door
      2. Interior door
    2. Types of Doors – Based on Materials
      1. Wooden Door/Timber Door
        1. Demerits of wooden doors
      2. Glass Doors
      3. Metal Doors
      4. Types of Doors – Flush Doors
      5. PVC Doors
      6. Types of Doors – UPVC Doors
      7. Types of Door – Aluminium doors
  2. Conclusion

Classification of doors in Civil Engineering

Doors come in a number of types. The selection of a door type, on the other hand, is determined by the location, purpose, aesthetic needs, material availability, security, and privacy. Doors types are typically classified as follows.

  • Location based
  • Based on material
  • Based on operation mechanism

Types of doors in civil engineering– location based

The doors types are classified as follows

  • Exterior Doors
  • Interior Doors

Exterior door

An outside door is one that allows entry to a building/house. An outside door’s main function is to safeguard the building as well as the security and privacy of the occupants of the building. While selecting an exterior door, style, colours, finishes, and aesthetic looks to match the architectural theme must be considered.

Interior door

Interior doors provide access to interior spaces like bed, kitchen, special functional rooms, toilets, etc. However, choice of material and type depends on the nature of privacy, security, and purpose of the room. Interior doors used to be lighter than exterior doors.

Types of Doors – Based on Materials

The door choice is confirmed based on the material to be used. For that, we should have a better idea of the readily available, durable, and aesthetically matching materials. Following are the popular choices of doors based on materials used in construction nowadays.

  • Wooden Doors
  • Glass Door
  • Metal Door
  • Flush Door
  • PVC door
  • Aluminium Door
  • UPVC door

Wooden Door/Timber Door

Wooden doors types are the most common and premium choice for both external and internal doors. They are the preferred choice due to their classy and elegant looks, high durability, and ability to match any architecture theme. Moreover, they are aesthetically pleasing and are widely available on a reasonable budget. Wooden doors can be custom-made for any functional requirements and design. They are the oldest material used and never lose their sheen even after long years.

wooden door
wooden door
  • Easily available
  • Easy working
  • Best material for front doors due to its high durability.
  • Used for any functional requirement.
  • Wooden doors are mostly polished rather than painted for exposing the natural grain looks.
  • Simple and easy installation.
  • Carving works are easily done on wooden doors.
  • Wooden doors are soundproof, got high thermal insulation capabilities and are strong.
Demerits of wooden doors

Even though wooden doors are superior materials they have their demerits also. However, needs periodic maintenance to retain the sheen and looks.

  • Needs periodic maintenance to retain the sheen and looks.
  • Wooden doors on long exposure to moisture may deteriorate.
  • Prone to termite attacks.
  • May sags

Glass Doors

Glass doors are for areas where the availability of natural light and open feeling is the main functional requirement. They are mainly used in areas where privacy is not a prime factor-like back yard, balcony doors, cabin doors, etc.

Glass doors are elegant and give an enhanced look to the house. However, the main problem with glass doors is the safety and privacy factor and the possibility of glass breaking. The glass breaking problem is managed by using small glass pieces for front doors. The glass should be safety glass or toughened glass.

Metal Doors

Steel is one of the preferred and favorite alternatives to wood for both external and internal doors. Mild steel or Galvanized steel is used for the manufacturing of doors. These doors are manufactured in solid and hollow types and are a safer, durable, and stronger option when compared to wooden doors.

metal door
metal door

Steel door frames are usually combined with wooden, PVC, steel, and flush door shutters. Steel door frames are manufactured by pressing steel sheets, angles, channels, etc. Holdfasts and hinges are welded to the steel frames.
Steel frames are popular and are used for residences, factories, industrial buildings, etc. They are economical than conventional wooden frames.

Metal door shutters are manufactured from high-quality cold-rolled Mild Steel (MS) sheets, with a steel face and rock wool or foam insulation. Steel is a more economical and stronger option compared to other materials even though steel may not look as attractive as wooden or glass doors.
Metal doors are available in different tones and shades. They are durable, have minimal maintenance, and provide excellent security.

Types of Doors – Flush Doors

The flush door is made of a timber frame covered with plywood from both sides. However, the hollow core is filled with rectangular blocks of softwood just like block boards. Flush door surface finished with decorative finish by fixing veneers. The flush door is usually laminated or veneered to match the architectural themes. These doors are usually hinged type and have one side opening only. The frame can be of wooden, PVC, or steel.
Flush doors got a seamless look and are economical, look elegant, and are easily available in the market.

flush door
flush door

While providing these doors for toilets, baths; the inner face of the door should be covered with aluminum sheets to protect against water.

PVC Doors

PVC or polyvinyl chloride doors are a very popular choice for doors. They are available in a range of colors and styles. Furthermore these doors have high resilience, are anti-destructive, termite-proof, moisture-resistant, lightweight, etc. As a result they are best suited for areas with moisture chances like bathroom areas.
Polyvinyl doors come in a variety of designs types. colors, style and looks beautiful. Similarly these doors do not corrode like steel or disintegrate like wood and do not need much maintenance.
They are very simple and easy to install and are scratch-proof. These doors are not preferred for front doors due to their lightweight characters and inability to resist environmental conditions. These doors are cost-effective when compared to wooden and metal doors.

Types of Doors – UPVC Doors

uPVC stands for Unplasticised Polyvinyl Chloride. It is a form of plastic that is hard and inflexible, also known as rigid PVC. UPVC doors are a preferred choice of architects and home owners due to the superior qualities they offer when compared to other door materials like wood, metal , PVC etc

  • Easy to clean and maintain – UPVC doors can be cleaned by simply wiping with a soft cloth soaked with mild detergents even though they may not peel or cracks after years of usage.
  • UPVC Profiles are manufactured to accommodate double glass units (DGU) in fact provides excellent thermal and acoustic insulations. Furthermore glass panes can be substituted with reflective glass to reflect sunlight and keep the rooms cooler in summers.
  • Durability – UPVC is a highly durable material, in addition to that allows for the construction of doors and windows that are long-lasting. In addition to all above they are dust-proof, termite-proof, moisture, and weather-resistant.
  • Ease of installation – Similarly UPVC doors are very fast and easy to install.
UPVC doors
UPVC doors

Types of Door – Aluminium doors

Aluminium doors due to their excellent and durable qualities are the most preferred option for designers and architects. They are durable, strong and maintenance free material. The fabrication and installation is very easy and got the choice of using as member for DGU units for thermal insulation applications. Aluminium is expensive, however considering the superior qualities aluminium is preferred in most of the areas.


Apart from the types described above there are a lot of doors varieties available in the market to cater each and every situation and applications. However, these door type selection has to be in line with the requirements.