FLAT ROOFS ( TORCH DOWN)
There are many types of flat roofs materials and applications. Torch down is one of the most popular and common types of application used in Ontario.
In torch methods, sheets of modified bitumen
membrane are rolled out onto the roof, heated
by a propane torch until the seams are melted
together to create a waterproof seal.
Bitumen is made from asphalt, a tough
material that is used in many roofing applications.
This type of roof can expand and contract without melting or cracking during the change of seasons.
1.Cap sheet: the finish bitumen granule cap sheet. granules add fire resistance, colour options and UV protection. The torch is used heat the bottom of the cap to the top of the base sheet. When the two layers are pressed together, they form a seal.
2.Base sheet: this is the first layer of modified bitumen membrane torched down.
3.Overlay board: supports the roofing membrane.
4.vapour barrier: prevent condensation and moisture.
5.Insulation: applied first, attached with screw and plates. retains heat in the structure.
6.Roof deck:
There are two main types of torch down roofing; two-layer and three-layer systems.
Both systems have a base and cap sheet, but in the three-layer system, after the base sheet, it’s applied a smooth cap sheet, and finish with a granule cap sheet. This extra layer helps extend the life of the roof and usually enhances fire resistance and energy efficiency.
ADVANTAGES
• DESIGNED FOR ALL CLIMATES,
• EXPANDING AND CONTRACTING WITHOUT MELTING OR CRACKING
• LONG LIFESPAN.
• RESISTANCE TO UV RAYS
• REFLECTIVITY TO KEEP THE BUILDING COOL
• ENERGY EFFICIENT.
• EASILY REPAIRED.
DISADVANTAGES
• DIFFICULTY ON INSTALLING THESE SYSTEMS.
• RISK OF FIRE
• REQUIRES SAFETY TRAINING
• SLIGHTLY EXPENSIVE BECAUSE OF THE EXTRA TRAINING, INSURANCE AND EQUIPMENT COSTS INVOLVED
