ºÃÉ«ÏÈÉúTV

Environmental pressures may result in fewer domestic garages being built in the future, but there is still plenty of demand and many existing installations that will need replacing or upgrading.

Since 2005 garage doors have been required to be CE marked to the product standard BS EN 13241, which covers a range of performance and safety issues. However, specifiers should look beyond the CE mark and confirm the level of performance, especially for particular requirements

Types of domestic garage door

One-piece up–and–over This is the most common design and comes in two versions:

• Canopy. Door leaf guidance is provided by vertical side runners and the lifting spring is attached to the top of the door. About a third of the door protrudes when open

• Retractable. Horizontal tracks on top of the frame protrude into the garage space. Lifting springs are located on both sides. This system is preferred for automatic operation but additional clearance is required.

Sectional overhead Doors comprise horizontal metal sections that run vertically in the plane of the door before turning horizontally at the head of the opening into the garage, which reduces the space required for movement.

Roller doors Compact and do not extend into the garage as much as up-and-over doors. The door leaf comprises slats into which clear polycarbonate panels may be incorporated. Guide channels on the edges reduce heat loss and improve security.

Hinged doors Usually supplied in pairs, hung on at least three hinges on each side.

Door leaf materials

Steel door leaf material needs to be protected from corrosion. Typical specification is to BS EN 10326, at least 0.4mm thick, hot dip galvanizing with a minimum 275g/m2 of zinc coating on both sides. Finishes include PVCu and polyester powder paint.

Aluminium extruded to BS EN 755 at least 0.6mm thick provides corrosion resistance. Polyester powder coatings to BS 6496 or with third-party certification should have a life expectancy of 20 to 30 years.

Composite insulated metal garage doors may be specified for improved thermal and acoustic insulation performance. The hollow void is filled with foam insulation.

Timber garage doors may be constructed from solid wood or a combination of solid timber and timber-based panels. The key specification issue is the risk of decay. This can be mitigated by using naturally durable species of timber, a preservative or timber-based product suited for external use.

Glass reinforced polyester (grp) garage doors are built around a galvanized steel frame. Confirmation of impact resistance, good performance in sunlight and colour stability should be sought.

ABS doors are also available and PVCu may be on the market soon. Performance will be similar to grp but at a lower cost.

Other components

Door frames are typically galvanized steel that can be polyester powder coated. Timber is the common alternative. Automatic doors rely on additional components including radio receivers, manual switches and door releases, lights or sounders to warn of door movement, safety devices and motors to operate the door. Enhanced security can also be provided with shoot bolts and multi-latch locking, and improved weather tightness can be achieved with weather-stripping.

Maintenance issues

Typical servicing cycles are based on number of operations (5,000) and six monthly and annual inspections, including lubrication, tightening of fixings and the replacement of worn parts. Springs may need to be replaced after 25,000 cycles or every five years.

Redecoration cycles will depend on the standard of appearance required and the expected service life of the decorative finish. Makers recommend regular cleaning.