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.
Specification options
| Capital cost £/ door | Net present value for 60 years £/ door | Expected service life years |
|
| One piece up and over canopy garage door | |||
| Galvanized steel with polyester powder paint finish | 427 | 2,000 | 20 - 50 |
| Galvanized steel with PVC (Plastisol) coating, 200 microns nominal thickness. | 478 | 1,960 | 30 - 50 |
| Timber door; External grade plywood to BS EN 636-3 with paint finish. | 960 | 2,800 | 30 - 50 |
| GRP faced garage door with galvanized steel chassis. | 1,346 | 3,700 | 20 - 30 |
| Other garage door types | |||
| One piece up and over retractable door. Galvanized steel with polyester paint finish | 491 | 2,100 | 20 - 50 |
| 4 panel (slat) galvanized steel hollow core sectional overhead door with PVC (Plastisol) coating, 200 microns nominal thickness | 853 | 2,390 | 30 - 50 |
| Aluminium slat, polyurethane foam insulated roller door with PVC (Plastisol) coating, 200 microns nominal thickness and remote control automatic operation | 1,406 | 3,790 | 40 - 60 |
Table notes
A discount rate of 3% is used to calculate net present values.
Costs are for installation of doors only. Door width 2,134mm, height 1,981mm. All doors manually operated unless stated to be automatic. Ancillary work such as electrical supplies and preparation of opening and door frame is not included. Costs in use include replacement, annual servicing, minor repairs, and recoating finish.
Costs are indicative and represent the average of a range. A cost analysis based on project specific information is essential for a realistic best value appraisal.
Made to measure garage doors, fancy patterns and special decorative finishes such as textured or wood effect finishes will cost extra.
Service lives are taken as average of the ranges and assume spare parts can be obtained for the door mechanisms.
First published in Building, 2008
Further information
BLP provides latent defect warranties for buildings www.blpinsurance.com
Further information contact peter.mayer@blpinsurance.com or telephone: 020 7204 2450