Different Types of Door Cores
There are many different types of door cores and choosing the correct door core is important from the point of view of both price and performance. Generally, the more materials used in a door, the more expensive it will be and conversely, the less materials used, the more a door will be liable to warp and the less effective it will be to prevent heat loss or act as a noise insulator.
Metal Door Cores
Even metal doors have many different types of door cores but the five most common ranging from most expensive to least expensive are temperature rise, steel stiffened, polyurethane, polythene and honeycomb.
The temperature rise door core is resistant to fire and is a laminated construction which slows down the movement of heat from one area to another, providing valuable escape time for a building's occupants.
Steel stiffened door cores have steel ribs welded within the door skin and are often used as security doors, being difficult to break through or cut. The steel ribs add strength and stability to the door which increases the lifespan of the door.
Like the temperature rise, fire resistant door core, Polyurethane door cores are also a laminated construction which makes them especially suitable for use as exterior doors in locations with cold weather conditions.
Also featuring a laminated door construction, the Polystyrene door cores offer good insulation properties and are especially suitable for doors which require a U-factor or an R-rating. The U-factor indicates the rate of heat gain and loss and the R-rating measures the rate of heat transfer.
The last of the many metal core types is the honeycomb core which can be used for interior and exterior doors where there is no requirement for good insulation. This door is generally the least expensive and the least secure option.
Wooden Core Types
Moving on to wooden doors, there are solid wood doors available made wholly from lumber, but these are an expensive option compared to doors where wood or other laminate veneer is fixed to one of the numerous different types of door cores that are available for wooden doors.
The lightest and most affordable option are the hollow core doors, though they are somewhat misnamed since they are not actually hollow but are built around a wooden frame with veneer attached. The "hollow" doors being made stable by a honeycomb or inner frame of cardboard or foam with solid wood being used in the area where the handle, catch and locking mechanism are located. Hollow core doors are often used for internal doors such as bedroom and bathroom doors in residential houses where heat insulation and strength are not so important. Of all the different door core types, hollow core doors are the lightest and easiest to install. They open and close easily with a minimum of effort, only require lightweight hinges and do not have good insulating properties.
Situated between solid wood doors and hollow core doors on price are solid core doors. These are doors with a solid core which can be made from a variety of materials, often coated with a real wood veneer which achieves the look of a solid wood door but at a more affordable price. Heavier and providing better insulation than hollow wood doors, solid core doors still come in a range of different types of door cores which vary depending on the use to which the door will be put and the characteristics required of the door for insulation, security, fire resistance etc.
Some of the more popular solid cores for doors are particle board core, timberstrand core, stave or composite lumber core and an agrifibre or mineral core. Particle board core are prevalent, widely used and the most popular of solid door cores due to its good all-round performance, coupled with excellent availability and affordable price. Particle board cores are made from ground-up wood from offcuts and recycled timber, mixed with glue and pressed into shape. Depending on the particles used, the glue used and other additives, particle door cores can be fire rated at twenty minutes, thirty minutes or forty-five minutes.
The strongest of the solid door cores is the timberstrand core made from strands of different species of tree combined with special resins to create a much stronger door than those with a particle board core. Often the choice for solid core doors requiring windows or panels within the door, this is the heaviest of the solid door cores.
Also widely used among the different types of door cores, is the stave or composite lumber core which uses blocks of wood or "staves" from the same species of wood. The staves are finger-joined and glued to give a strong stable door that weighs less than the particle board doors and offers impressive durability.
Fire Resistant Solid Door Cores
Last but definitely not least, are the fire resisting agrifibre or mineral, solid door cores. Lightweight and easy to handle but not easy materials into which screws can be inserted, these cores require blocking around the areas where fixings and fixtures such as door handles and locks are going to be attached. On the plus side, the agrifibre and mineral cores do provide excellent fire resistance with the agrifibre offering fire resistance of between three quarters of an hour and an hour while the mineral core is fire resisting for between an hour and an hour and a half.