FAQ: The abbreviation FENSA stands for FENESTRATION - SELF ASSESSMENT.
The uk dictionary definition of the word fenestral or fenestrate is " belonging to or like a window" The word fenestration is "the arrangement of windows in a building". FENSA is used by double glazing uk trade companies to certify that their replacement windows and doors installed comply with Building Regulations Document L (and more), actually checking av. 1% of all replacement windows installations.
Did You Know?
When people ask "does PVC-U fade" it is likely that they have seen a rogue door panel that has gone off colour, like this one. Either that, or they have most likely heard 'stories'.
In the early days door panels were made out of fibreglass (GRP = glass reinforced plastic). It was a simple and natty idea, instead of fitting double glazed sealed unit(s), make a feature panel and fit that instead, so that a PVC-U door looked more like a traditional wooden door. Great idea, but not long after their introduction, and to the horror of the industry, they did not hold their colour, and yellowed. They could not be made to be U.V. stable and were quickly discontinued, but not before a lot of people saw them and thought that it was PVC-U that was going off-colour.
Next to come was thin sheets of PVC-U vacuum formed to give the same effect. An indoor sheet and an outdoor sheet are formed to shape and then glued to an insulating foam core, job done. The problem was that most of the early ones only held their colour for about twice as long as the early fibreglass ones, because the U.V. stability had been ruined by the heating up process necessary to vacuum form them. Following much testing and research it was concluded that a lot of the problem was being caused by only one side of the PVC-U sheet being heated, and also being heated up too quickly.
Now that this is all old hat and well known in our industry, the up to date recognised methods of manufacture and machinery means that it is very rare nowadays to hear of new door panels discolouring.
If you fancy just getting out the paintbrush, see: