There are several different styles of entrance and exit doors designed for residential properties:
Residential Doors – Residential door is the term given to ordinary single doors, including PVCu doors, timber doors and composite doors and generally refers to the main front or rear entrance / exit door. Residential PVCu doors often have one or more fixed side panels or an attached ‘flag’ window.
Double Doors – Double PVCu doors are often referred to as French doors and can be manufactured to open either inwards or outwards. They have a main (first opening) door and a secondary door. For wide ‘brick to brick’ openings one or more fixed side panels need to be included in the design.
Patio Doors – Two types of patio PVCu doors are available. Tilt and slide patio doors offer ventilation by tilting the door inwards without having to slide the door open whereas an in-line patio door only offers the slide function. Both types of patio PVCu doors can be manufactured in 2, 3 or 4 sections.
Bi-fold Doors – Bi-fold doors can be manufactured with as many as seven sections or door leafs, each up to one metre wide. This means that bi-fold doors provide the widest opening of all door styles. They can also be designed so that some or all of the door sections move to one side or the other.
PVCu is the abbreviation of Un-plasticised Polyvinyl Chloride and is exactly the same product as uPVC.
In day to day use the terms have become interchangeable but officially PVCu has been used since the late 1980’s, bringing the UK into line with the rest of Europe. This is simply because in most European languages the noun (PVC) is placed before the adjective (unplasticised).
Polyvinyl Chloride (PVC) is a chemical compound of chlorine, carbon and hydrogen originating naturally from petroleum, natural gas and sodium chloride (common salt). PVC is commonly used in ‘plastic’ sports bags and some shoes after being modified by softening it with the addition of ‘plasticisers’.
Un-plasticised Polyvinyl Chloride means that the product has not been modified and therefore not softened, but in its pure form it is still not entirely suitable for windows and doors. Stabilisers and additives are required to improve the longevity, and ensure that it is UV stable and does not discolour.
The amount of these additives differs from one manufacturer to the next to form different compounds, though two common additives are acrylic to harden the compound and Titanium Dioxide to make it appear whiter.
As a result, PVCu: –
• Does not biologically decompose or rot and can be recycled
• Is resistant to weathering
• Is low maintenance
• Is tough on impact
• Retains its shape in normal climate conditions
• Can be reshaped and formed at high temperatures so can be extruded to form window and door profile and even bent to form arched windows
The term PVCu profile refers to the cross section (shape or profile) of the various extrusions and there are hundreds of different types of PVCu extrusions for windows and doors.
PVCu profiles for PVCu doors are also available in a wide range of colours including 6 different shades of white, woodgrain effects attempting to replicate, mahogany, oak and rosewood among others, and solid colours such as red, blue, black, green and cream.
When specifying white PVCu doorss it is important that the frames and sills are made from the same compound and therefore are the same shade of white. O1 is the ‘whitest’ shade of white but it would be unsatisfactory to fit it onto a ‘creamy’ coloured white sill.
The issue is highlighted when it comes to conservatories as many installers use conservatory roofs and frames from different manufacturers. This could result in the frames being a different colour white to the roof spars – and sometimes a different white again from the sills and trims.
Companies manufacture their own PVCu profiles for the many types of window and door frame, conservatory roofs, trims and sills are therefore at a distinct advantage as they can offer a colour match across the full range of products.