Hello! I'm trying to redo my patio and expand the area a bit. The old patio has been there for over 20 years, so it was time to fix it. There will be joists against the facade on two sides of the house. (Previously, there were three sides on piers and a joist under the entrance door). On the longest wall side, I've cut the facade batten up to the level that will become the decking surface. As the picture shows, the seam between the facade boards becomes dangerously open to moisture and other unpleasantness, so I'm considering using foundation insulation paper like YEP 2500 TJB (Byggmax).
Is this a correct decision...? Is there anything better or more suitable for the purpose?
From the lower edge, it's 300mm wide up to the sawn batten.
Grateful for expert advice.
