I made the swing out of old deck boards. The pressure treated 6×6′s are cemented 4 feet in the ground. The top two boards are 10 feet long by 3 inches thick by 10 inches high I used large 10,000lb bolts for the weight and look (yes over kill)..lol . I sewed water and bed bug mattress cover on cushions then outdoor material over top. I used our old original queen size foam mattress from our camper. I bought large springs for more comfort but haven’t put them in the chain yet. I have one coat of gel stain and about 5 coats of urethane. I used tools and hand carved the ends and routed the edges.