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Transporting damp materials in bulk can be difficult and dangerous if not done correctly. Moisture can add to the weight of material being transported, so it’s important to properly calculate the weight so that the right bulk bag can be used.

By utilising high-quality bulk bags and in accordance with proper procedures, you can assure the safe and efficient transport of moist materials. Custom Bulk Bags is a leading manufacturer and supplier of bulk bags in South Africa. We produce up to 3.5 million bulk bags per year. 

Our products can safely hold between 500kg and two tonnes of material per bag, depending on your specifications. We also offer numerous optional extras, including UV coatings and inner liners that improve the performance of the bulk bags for damp products.

What do we mean by damp products?

Damp goods are those that have a high moisture content. To maintain quality and safety, some damp products require specific handling and transportation procedures. Construction materials such as cement, sand and clay, are common examples of moist products that can be transported in bulk bags. 

The water content will add to the weight of the material, so a cubic metre of river sand will be heavier than a cubic metre of dry sand. Understanding these products’ qualities is critical for selecting the suitable bulk bags and ensuring their safe transportation.

Choosing the right bulk bag

Choosing the right bulk bags and speccing them properly is essential. Custom Bulk Bags has a variety of products developed exclusively for this purpose. For example, waterproof bulk bags are coated or laminated to provide an extra moisture barrier. They are suitable for products that require moisture to be kept in the material, such as cement.

In addition, UV-resistant bulk bags are coated with chemicals that protect against ultraviolet (UV) radiation, guaranteeing that sunlight exposure does not damage the bags or their contents during transportation and storage.

When moving viscous liquids, such as lubricants or molasses, bulk bags need to be able to fully contain the liquids. This requires a special inner liner that prevents the liquid from seeping through the gaps between the woven polypropylene tapes in the fabric of the bags.

Best practices for handling damp products

To ensure the safe delivery of damp materials, proper practices must be followed. Firstly, proper stacking techniques must be used. Make sure the bulk bags are properly stacked, using appropriate stacking patterns and maintaining stability from the base layer. This will protect the bags and the items inside from damage.

Next, secure and protect the bags by using straps or other securing methods to keep the bags in place while they are being transported. Also protect the bags from sharp objects or harsh handling that could cause punctures or tearing. 

Remember to inspect the bags on a regular basis for evidence of damage or moisture infiltration in the polypropylene tapes. Address any concerns as soon as possible to avoid further damage.

Transporting damp materials in bulk quantities necessitates careful preparation, the proper equipment and adherence to best practices. You may ensure the safe and efficient transportation of your items by using high-quality bulk bags and following the advice offered by Custom Bulk Bags. 

Our expert consultants will guide you through the ordering and specification process to ensure that you receive the perfect bulk bags for your needs. For more information about our bulk bags or to get advice on the ideal design specifications, please contact us today.


Custom Bulk Bags is a leading South African manufacturer of woven polypropylene bags for various industries, such as mining, chemicals and food. We are able to produce over 3.5-million bulk bags per year, keeping our customers in stock at all times. Our bags adhere to the highest levels of quality as a result of our stringent in-house testing and quality control programmes.

Custom Bulk Bags holds ISO 9001 certification and we currently have a number of UN-certified designs. We are a Level 2 B-BBEE manufacturer and supplier and fall under the ownership structure of Deneb Investments Limited. For more information on our products, contact Follow us on Facebook, LinkedIn and Instagram for our latest news and industry insights.