How To Lay Decking On Soil Or Grass | Ronseal
Lay the decking on the grass in your decided design and leave the right expansion gaps between boards (5 to 8 mm along the length of timber boards, and 3 mm along the ends). This will show you if you have enough decking to complete the job. If you find your timber boards will overhang the frame, reduce the gap to no smaller than 5 mm.