Hazard of temporary warehouse
1.INTRODUCTION
Temporary warehouses (tent warehouses) can be constructed at low cost and in a short period of time, and can be easily dismantled and expanded. It can be designed to suit the intended usage and the shape of the land, therefore many industries utilize the temporary warehouses. On the other hand, there are potential risks such as aging deterioration of membrane sheet, damage to storage goods due to temperature changes, and severe damage due to fire spread. This article describes the basic structure of temporary warehouses, major risks, and key points of loss prevention measures.
2.CONSTRUCTION
Temporary warehouses have a “membrane structure” in which a metal framework is covered with a membrane sheet. Exterior wall material is composed by membrane sheet, and the warehouse is much lighter than other constructions. The structure supporting the membrane sheet is also lightweight, allowing large spaces to be built without pillars.
As the warehouse can get stuffy and hot, attention should be paid to avoid storing precision products which are sensitive to temperature changes and hazardous materials which could initiate/start unplanned fire. In addition, ultraviolet rays can cause deterioration of the membrane sheet, and it is important to select proper materials.
Typical tent structures include fixed type and push-pull type (bellows tents).
3. POTENTIAL RISKS
Temporary warehouses often contain many combustible materials and have high fire loads. In the event of a fire, the combustible and membrane sheet becomes additional fuel for fire to propagate and spread. In most case, firefighting equipment such as fire detectors and sprinklers are not installed. If automatic detection/suppression system is not properly installed, there is higher probability that initial emergency response and subsequent firefighting activities might be impaired in the event of a fire.
Strong winds can blow away the membrane sheet and other structure components, causing damage to surrounding facilities. To minimize such risks, the tent warehouse should be firmly anchored to the ground and the membrane tightly secured. If aging or minor damage of the components is left untreated, the warehouse will be more susceptible to the effects of rain and wind. Damage to membrane sheet might cause/allow rainwater to enter the warehouse and damage storage goods.
4. LOSS PREVENTIVE MEASURES
The main loss prevention measures for temporary warehouses are listed below.
- Prohibit or restrict storage of hazardous materials such as flammable liquids and chemicals in the warehouse and comply with handling rules.
- Install fire extinguishing equipment in accordance with fire risks, and implement periodic maintenance to ensure reliability and effectiveness.
- To prevent the electrical fire, do not place the combustibles directly under lighting fixtures. Also, battery should not be charged in the warehouse.
- Smoking should be prohibited in the warehouse, and control the hot work management strictly. Temporary warehouses should be included in the safety audit route to check the management condition periodically.
- Use non-combustible fabric/materials for membrane which meets flame propagation performance (refer to NFPA701). Periodically check for deterioration of membrane sheet and other structures, and promptly repair even if minor damage is detected.
- Erect tent warehouse with minimum clearance of 3.7m (12ft) to all structures and other tent warehouses (refer to International Fire Code 2021, Chapter 31).
- Ensure adequate unobstructed access to the tent warehouse for manual firefighting.