fiberglass shower installation Home › Forums › Public Forums › General Plumbing › fiberglass shower installation This topic has 1 reply, 2 voices, and was last updated 21 years, 3 months ago by Retired plbg1. Viewing 1 reply thread Author Posts 4 Jan 2003 at 5:28 am #276160 MasterPlumbersKeymaster what is the recommended material to fill the space between a one piece fiberglass shower and the concrete slab it is to be installed over? 4 Jan 2003 at 12:33 pm #293523 Retired plbg1Participant Some people put cement,sand, styophome and I heard that spray foam you buy in a can. Check with the manufacture of your product and see what they recomend. Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In