re: Re flooring an aluminum boat

go with 1/2" ply, the 3/4 is overkill and just adds too much weight.

i used treated plywood and i found its best to leave it natural so it can fully dry. this keeps it from rotting and the plywood lasts a good 6-8 years or more. when i glued carpet to it or painted it it was all rotten in just 2-3 years because it traps moisture and doesnt let the wood dry out after getting wet. and my boat sits outside completely uncovered and exposed year round.

in my boat i just laid it in there and didnt secure it at all. this made it easy to lift the floor to clean out under it when leaves and trash or whatever starts blocking up the drains.

i had a fab shop put in an all aluminum floor in my brand new "basic" vee hull model 17ft x 52" Alweld boat. mainly did it since they were already going to be building storage seats and a casting deck for it too but it wasnt cheap. cost me $1200 including materials to have it done but man does it look and function great, zero maint for life too.