- ila The Order of THG's bathtub, tub spout / filler is 10 - 12 weeks The Order of Waterworks / Aero Thermostatic Control valves is 14 - 16 weeks The Order of Stone materials is 8 weeks The estimated duration for on-site construction is appr. 6 weeks including of Protection, Demolition, Plumbing & Fixture, Carp