Wet Wall


 Uncomplicated. By design.

The All-in-One that Works

The pre-fabricated Wet Wall module contains all the mechanical services that are so time-consuming to install in the field – plumbing waste and vent lines, water lines, heating and cooling ducts, electric conduits and boxes – into an organized, cost-effective unit.

Wet Walls are designed for speed.The modules are delivered to the jobsite, hoisted into location, connected together, and within days, the mechanical systems are ready for testing and inspection!

With all the mechanical components contained in a simple, clean shaft, there are no joists to cut, no beam penetrations with stiffener plates, no soffits, no interference between trades, and no variations from bathroom to bathroom. The Wet Wall modules ship completely tested and pressurized. Designed to stack for multi-family projects, the modules extend above the floor and descend below the ceiling of the room below. The floor-to-floor height does not alter the Wet Wall module, because the interim connecting pipes and ducts are field measured and installed. On-site waste is kept to a minimum.


Wet Walls are available with single side Bathrooms, back-to-back Bathrooms, Kitchens to Bathrooms, as ADA (Handicapped) accessible, in rights and lefts. The basic Wet Wall is non-combustible. Cast iron waste and vent piping, low-sone fans, and copper water piping is standard, but ABS waste and vent and PEX piping is a popular alternate. Note: cast iron is appropriate for multi-story applications for better acoustic control.


What’s Typically Included:

  1. Galvanized steel chassis
  2. H.C. Grab bar backing
  3. Shower mixer
  4. Toilet flange
  5. Main waste riser
  6. Vent riser from below
  7. Vent riser to roof
  8. Cold water riser
  9. Hot water riser
  10. Hot and cold water supplies to fixtures
  11. Washing machine box
  12. Electric
  13. Solar PV conduits
  14. Range hood duct riser from below
  15. Back-to-back medicine cabs
  16. Bath fan and duct
  17. Bath exhaust fan riser
  18. Dryer vent riser


Wet Wall can help with LEED points in several ways:

MR 2.2 Material Efficient Framing – framing, piping and ducting are all cut at the factory, there is very little on-site waste,

MR 3 Local Sources – Wet Wall is manufactured in Northern California. In most cases, the factories producing the various parts are local, reducing the transportation component of the net embodied energy.

EA 7.1 Water Heating, Improved Hot Water Distribution System

ID 1.1 Innovative Design – the Wet Wall is manufactured off-site saving time, and there is no on-site cutting so the waste is minimal.

Wet Wall embodies the three sustainability goals of Malpas Sustainable Design:

  • Obvious – The selection of sustainable or green materials
  • Less Obvious - An efficient process to fabricate and install
  • Non-Obvious -  Elegantly engineered so each component is working at its optimum