Summary Statement
Roofing work at night increases risks of falls and fires, and reduces quality of craftsmanship. It should be avoided.
“Night roofing,” or roofing work performed after dark, is increasingly popular with building owners and consultants who want to avoid asphalt smells, noise, and disruptions to building operations during regular business hours. There are obvious hazards connected with night roofing, however, and some that are not so obvious. These risks apply equally to building owners and roofing contractors.
Accidents and InjuriesRoofing entails working at heights with molten asphalt and open flames, handling heavy materials, operating power equipment, and other high-risk activities. Workers are potentially exposed to burns, cuts, fractures, and falls. These hazards are compounded by working at night when no amount of lighting can replicate daylight conditions. Shadows, glare, blinding light, and miles of cable increase the risk of personal injury and property damage. The impact of odd working hours and unfamiliar conditions on personnel must also be considered.
Fire Hazards
Some roofing systems require the use of propane torches that may ignite
building material. Fires can smoulder for several hours before breaking
into open flame. During daylight operations a roofing contractor typically
provides a smoke or fire watch for one or two hours after torching work.
This isn’t possible in the dark where smoke from smouldering material
can be difficult to see.
Quality of Work
In addition to safety hazards, working in the dark can lead to poor workmanship
and take longer to complete because of reduced production schedules. Both
factors add considerably to costs. Some roofing system warranties may
not apply to work completed at night. Condensation is another factor to
consider. Whether it appears as moisture or frost, condensation present
during roofing installation can cause serious problems later. The same
is true of rain. Changing weather patterns difficult to detect at night
can bring rain during installation, compromising the future effectiveness
of roofing systems. Water damage to building interiors from unexpected
rain can also be significant when old roofs have been stripped off prior
to re-roofing.
Summary
The combination of safety hazards, poor quality control, and increased
liability for both building owners and roofing contractors makes night
roofing unacceptable. Owners and their consultants should not consider
night roofing a viable option to avoid inconvenience or disruption during
regular business hours. The losses in safety and workmanship far outweigh
any advantages to be gained from night roofing.
Ontario
Roofing Trade Labour-Management Health and Safety Committee
Construction Safety Association of Ontario
Ontario Industrial Roofing Contractors Association