How do I attach cover locks to an in ground spa? Mel January 05, 2021 04:48 Updated Follow The lock portions are installed with screws, flat on the surface that the spa in in. We suggest that you use screws suitable for the surface that you are drilling into. See below for examples in Brick and wooden decking. Related articles My spa is in my deck, can I still use a cover? Can you make a cover for an inground spa pool? How do I measure my spa cover? How do I clean my Spa Cover? My spa has a wooden ledge under the edge, How do I measure for a spa cover? Comments 0 comments Article is closed for comments.