Material
Timber bifolding doors:
this material will need to be painted or stained every five or so years and swelling and shrinkage may stop the doors from operating correctly.
PVCu bifolding doors:
sections are normally bulky and can suffer from expansion and contraction, which can hamper the functionality of your doors.
Aluminium bifolding doors:
thermally efficient, the slim line sections are still very strong. Available in extensive colour options, they are also easy to maintain.
Glazing
U value:
the thermal rating given to the sealed unit (lower value gives better rating), a good benchmark is a u value of 1.1.
Sound:
triple glazed units assure better sound insulation benefits than double glazed units.
Cleaning:
all units can be finished with a self-clean coating, reducing dirt levels and thus keeping the product cleaner.
Security
The recognised British Standard is Pass 11 and the European Standard is W2.