One question we are commonly asked is what the ‘D’ stands for when it comes to adhesives. Many people online find adhesives that look similar but then they see a ‘D2′ or a ‘D4′ next to them. This can seem like jargon but it is a quick way of noting different properties of an adhesive.

The D grading stands for durability.

These gradings are part of the European standard BS EN 204 governing the classification of wood glues for non-structural applications.

There are 4 main types of durability grading, running from D1 to D4. The differences between these are listed below:

• D1 = Interior areas, where the temperature only occasionally exceeds 50°C for a short time and the moisture content of the wood is 15% maximum
• D2 = Interior areas, with occasional short term exposure to running or condensed water and/or to occasional high humidity, provided the moisture content of the wood does not exceed 18%
• D3 = Interior areas, with frequent short-term exposure to running or condensed water and/or heavy exposure to high humidity. Exterior areas not exposed to weather
• D4 = Interior areas with frequent long-term exposure to running or condensed water. Exterior areas exposed to weather

For those interested in the classifications, the bond strength requirement for the different classes is listed below:

We offer a range of products to suit these needs including:

• D3 Water Resistant Joinery Adhesive
• D4 Water Resistant Joinery Adhesive
• D2 Universal Woodworking Adhesive
• D2 Fast Setting Wood Adhesive
• D4 Wood Weld PU Adhesive