Damage to buildings and building support systems from volcanic ash can range from minor cosmetic damage to building exteriors through to catastrophic structural damage in extreme cases. The level of impact will be dependent on the amount and characteristics of the ashfall, the design and quality of the building and building support system and the environmental conditions at the time of and after ashfall.
Damage to buildings may be significantly reduced by taking several key steps before, during, and after ashfall.
The overall level of impact will be dependent on all these elements, as buildings act as an interdependent system. Mitigation measures can reduce and in some cases avoid impacts with rapid and regular removal of ash (when it is safe to do so).
However, clean up of building exteriors and interiors can be expensive, time-consuming and may need to be on-going (on-going ashfall or remobilisation of ash by wind and water)
BE SAFE DURING BUILDING CLEAN UP!
Roof tops may be slippery or at the limit of their load capacity! Be extremely careful when working on a roof, even on roofs with low to moderate pitch, and especially when covered with slippery material. Use personal protective measures when removing ash from roofs. Use a strong ladder, safety harness, filter facemask, gloves, and eye goggles.
For safety and prevention of unnecessary damage to roof material and surfaces, use protective measures during cleanup. For example, use planking, mats, plywood sheets, and pliable footwear to prevent slippage and damage from impact and abrasion; when using shovels, rakes, or other tools, be careful of the underlying roof surface; the full force of water from fire hoses can easily break lap shingles or tear lap roofing material.