I have some decking for which I've built the frame, and the main "floor" decking already but haven't done the sides for yet. The decking goes right up to the edges of the subframe that it sits on.
For the sides, i'm going to screw some more decking boards horizontally onto the side of the sub frame. However, I'd like there to be a 5mm gap between the decking top and the side, to allow for some expansion, and also to allow for a consistent flat surface for the boards on the side.
How i was thinking i might achieve this is by putting a 5mm plastic strip between the boards and the frame, where i'm screwing it in. (I was thinking plastic just for ease of cutting it up into the required size) I would then glue the strips to the board, in line with where the screws would go, before putting it onto the frame and screwing it on.
Does this seem like a sensible approach? Does anyone know of a product like this? Or a simpler way to do it with some cheap material?
EDIT - i just thought of one solution: buy a bag of nuts and bolts (or just nuts if they can be bought without the bolts) where the nuts are 5mm thick. This should be cheap and easy. Then, yuse the nuts as spacers. Ideally i would screw through the middle of each nut, but this might be tricky to manage.