An unserem Haus haben wir vor vier Jahren eine Holzterrasse aus Riffelhölzern (board spacing approx 0,5 cm) built. The whole on a solid wooden construction, because the ground around the house is about 40 cm lower. After heavy rains, as has often been the case lately, the space between the terrace and the floor resembles a mud bath, the ground is washed away and the construction begins to shake.
Can I fill the gaps between the boards with a joint compound (Silicone o. ä.) Mistake, so that the rain masses no longer run through the cracks, but pour into the garden?
Unfortunately, we have no experience with the treatment of wooden terraces, as you intend. But it could work with natural wood. You should try one or two joints. So you the silicone (Also available in different shades of brown) doesn't fall through the cracks, you should first clamp a round sealing cord made of foam and spray and smooth the silicone on it. Achieve better adhesion to wood, if you treat the contact surfaces with a primer beforehand. The terrace must of course have a slope, so that the accumulating water can be discharged in a collecting channel.