Flat Felt Roof FAQ's
Why do flat roofs cause so many problems?
The main reasons are:
- Use of inferior quality roofing felt
- Structural movement
- Bad design - not having sufficient fall on the roof or adequate outlets for water to drain from the roof
- Settlement - the roof retains water because the timbers supporting it have sagged and consequently allow water to pond away from the pre-set outlet
- Lack of maintenance - solar-reflective chippings or paint haven't been updated regularly to prevent sun damage from blistering and splitting the cap-sheet
- Puncturing - individuals walking and/or working on the roof without taking care. Heavy objects left standing in one location
- Poorly installed upstand flashings - flashings not fully returned into adjoining walls
- Poor workmanship - the roof covering not being installed to the manufacturer's recommendations and specifications
Why do typical traditional flat roof s only last around 10years?
Basically because poor quality materials are used and inexperienced installers fitting the covering. Most flat roofs fail in three main areas, they either split along the gutter drip flashing, expansion cracks appear between the decking joints, or the wall upstand flashing fails at the chase.
When we install a felt roof we always use a venting layer which eliminates expansion cracks, prime any brickwork and use either lead or GRP cloaking flashings and bond the second layer down onto the drip batten.
Can anything be done to improve the insulation and u-value?
Certainly. When updating a roof covering is an ideal time to upgrade. The added benefit is the reduction in energy costs at the same time providing a warm interior in the winter and cool in summer
How long will a new felt roof last?
This depends on the quality of material selected and which way the roof faces in relation to the sun. Our SBS 3layer systems will last in excess of 20years.
How many different types of roofing felt are there?
Approximately 20 ranging from basic Standard 2mm felt to High Performance Polyester 6mm cap sheets with intermediate layers of 3mm, 4mm and 5mm. Any system can be permutated to suit the required durability and your budget.
Are guarantees available?
Most certainly. They range from a 10year Company guarantees to 20 years insurance backed guarantees which cover materials and workmanship. All can be passed on to the new occupant if the property is sold which is an added selling point.