Whether it's made from block paving or wooden decking, weeds love your terrace! Wood is a living material, and when constructing your terrace you must leave a gap between planks to allow them to expand. Weeds will take advantage of these gaps to benefit from a soil that is damp and cool all year round, and from the light that falls through them - a right little paradise! The weeds are generally well hidden amongst the wood, and it's difficult to get them all out.
To eliminate weeds once and for all, a great solution is to use one of Roundup's ready-to-use Weedkillers for Patios, Driveways and Terraces. The weedkiller reaches even the deepest roots, ridding your decking of weeds ready for you to get started on your barbecues!
Your Roundup weedkiller will not stain the wood, but if you are in doubt, conduct a test by applying your weedkiller to a part that is not visible, and leave it to dry for 24 hours before treating the rest of your decking.