This is an
excellent, highly insulate material, which
from little or no external maintenance. It is
available and well tested and is usually the
lowest cost option of all three materials. It is mainly seen in white but also
available in Mahogany and Oak woodgrain styles. PVCu is by far the most popular
material for windows and doors today.
There are many well-proven PVCu extrusions available. Problems with
discoloration are virtually unheard of and most suppliers will warrant against this.
The design of the windows varies from company to company. Here are a few of
the main points. You may like to raise them with your supplier.
Internal or Externally glazed windows
Most PVCu systems will now give you this option. As a generalisation Internally
beaded windows (where the glass is held in from the inside) are considered more
secure and burglar resistant. That said there are a lot of satisfactory externally
beaded PVCu systems about - many of which feature either internal wedge
gaskets or a "double sided" tape which holds the external bead firmly in place.
You should investigate this particular issue with your supplier.
Thickness of PVCu walling?
Most PVCu systems for window and door construction are "multi-walled" with
internal reinforcement by means of either Aluminium or Galvanised Steel box
section. Wall thickness can vary from system to system - most are around 3 - 3.5
mm thickness. Generally speaking the "thicker" the walling - the stronger the
section. Ask your supplier for an example section and enquire if the frames
are fully reinforced. Note also that the greater the number of internal walls - the
greater the strength.
Depth or thickness of frame
Actual depth of frame extrusion varies from as low as 50 mm to a number at 70
mm and above. Most are in the 60 - 65 mm region. Clearly this does have an
effect on the structural strength of your replacement window or door. This is
especially worth bearing in mind wh