Winter Weather - Impact on Buildings
It’s important to consider how heavy snowfall, freezing temperatures and strong wind chills might seriously damage your business’s premises and to be prepared for such conditions. Snow and ice on a roof can exert vertical loads that can cause a roof to deflect or bow downwards. These extremes in weight load can also transfer horizontal forces through the structure that can cause walls to deflect outward at either the top or base of the wall. In addition, melting snow combined with rainfall can overwhelm building drainage systems as well as local drainage systems in the area which can result in flooding and damage. It is important that a full risk assessment is carried out and a safe method of work established, preferably by qualified and competent contractors. To protect against the likelihood of snow related damage to your property, it is important to develop a timely prevention and maintenance programme before, during and after the winter period. These simple practical measures should form part of your building maintenance programme.
MAINTENANCE BEFORE THE WINTER WEATHER BEGINS
Regular and systematic building inspections are a key part of any maintenance programme in order to help identify problems promptly and keep track of maintenance regimes, identified problems and actions taken.
Rainwater Removal - Gutters, Gulleys, Downspouts and Drains
Prevent damage caused by heavy snow and ice dam formation by doing the following:
- Inspect all gulleys, gutters, downspouts and drains and repair any damage
- Inspect and clean accumulated debris such as leaves, vegetation and silt from all roofs, roof drains, gutters, valleys and downspouts so that water will flow freely
- Inspect and clean accumulated debris such as leaves, vegetation and silt from the underground drainage system around the property to ensure that it will effectively remove water away from the building
- Inspect the structural elements of the building for accidental damage that may detrimentally affect the structural strength e.g. damage caused by impact from forklift trucks, high loaders etc.
Keep a record of identified problems and actions taken.
STEPS THAT CAN BE TAKEN DURING WINTER WEATHER
- Try to keep roofs, gutters, downspouts and drains clear of ice so water can freely drain away
- When clearing snow from yards, driveways and footpaths you should make sure that snow is not deposited against the foot of any downspouts as this may interfere with effective drainage
- Only where it is safe to do so, chip and channel any ice dams to ensure that water can flow freely
- Be watchful for signs of stress of the roof and wall structure such as cracking, splitting or twisting, particularly in trusses, purlins, joists, beams and girders
- Roof failures can occur at the exterior wall connections particularly in buildings with flat roofs so it is important to check the connections for signs of cracking, twisting or deflection
- Be alert to any unusual sounds emanating from the building such as cracking or creaking from the roof
- Specialist advice should be obtained if considering the removal of snow from roofs and this should only be undertaken if it is safe to do so and by a competent person following a risk assessment
- Keeping attics well ventilated can reduce the build up of snow and formation of ice dams
- If portable heaters are being considered you should first seek approval from your insurance company and comply with any additional requirements that may be required. In addition, heaters must be adequately maintained, staff must be trained to use them safely and ensure that fire risk assessments are updated to reflect the additional hazard.
Key Action Steps
- Do you know and understand the snow load designs for all the roof sections of your building(s)?
- Does your building maintenance programme include measures to ensure that your buildings are not compromised by snow events?
- Are you prepared for such events and is your business able to respond effectively to deal with such events?
Effective precautions are required for all work on roofing surfaces, no matter how short the duration, whether the work concerns construction, maintenance, repair, cleaning or demolition.