FA info icon.svg Angle down icon.svg Project data
Authors Justine Cook
Location Arcata, California
OKH Manifest Download

This is the Operation and Maintenance (O&M) manual for CCAT greenshed west wall. Please refer to it and keep it up to date with any O&M changes.

Summary[edit | edit source]

The CCAT greenshed west wall is a straw clay slip wall that was constructed using a wooden frame and filled with a straw and clay mix. Twenty-nine 'liters of light' are dispersed along the wall. The wall was finished using a lime plaster. The wall was well built, leaving very little required maintenance.

WestWall photo 1.jpg

Bottle wall.jpg

Operation[edit | edit source]

Fig. 1. Straw clay slip wall inside
  • IT IS NOT RECOMMENDED TO MOUNT OR HANG ANYTHING DIRECTLY FROM THE STRAW CLAY SLIP WALL. Objects should be mounted to the wooden frame instead (Figure 1 shows wooden frame where things can be hung from).
  • AVOID STACKING ITEMS AGAINST THE WALL that would prevent the wall from being able to breathe.

Maintenance[edit | edit source]

Fig. 2. Minor crack in plaster
  • REPAIRING CRACKS AND FISSURES (See Instructions section below): Overtime, the straw clay slip wall will be subject to deterioration due to weathering. Minor cracks in the plaster do not pose a serious threat to the structural integrity of the wall. However, it may be beneficial to patch minor cracks with a plaster to prevent the inside from accumulating too much moisture, preventing mold growth and insect infiltration. The straw clay slip wall needs to breathe, so a lime plaster is recommended. Refer to this page for detailed steps to recreating a similar plaster.
  • PLASTER TOUCH-UP (See Instructions section below): Touching up the plaster is more for aesthetic reasons and not absolutely necessary. It can be helpful if the plaster is beginning to wear away or fade.

Instructions[edit | edit source]


Patch up any cracks or faults first


Prepare a lime wash (lime putty, water, and desired pigment)


Dampen the wall with water as evenly as possible using a spraying mechanism. This step is important in preventing the wall from absorbing water from the lime wash.

Test patches

Do a test patch of your lime wash to make sure it is the color you desire


Use brushes to apply lime wash and let dry thoroughly

Cob wall fissure

If fissure is deep but not large or wide enough to bother making a straw clay slip fill, carefully ram dry straw into the fissure. If crack or fissure is minor, proceed to next step.

Plaster preparation

Prepare a lime plaster. Use a similar one to the one listed on the CCAT greenshed west wall page.


Dampen the immediate area with an even spraying mechanism to prevent the wall from too quickly absorbing the water out of the fresh plaster.

Applying plaster

Evenly apply plaster and allow to dry.

Schedule[edit | edit source]

  • Check for severe cracks or faults in the wall
  • Check for severe cracks or faults in the wall
  • Decide whether or not the plaster needs a touch-up
FA info icon.svg Angle down icon.svg Page data
Part of Engr535 Development Technology
Keywords ccat, ccat active project, ccat building, earthen plaster, alternative building
SDG SDG11 Sustainable cities and communities
Authors Justine Cook
License CC-BY-SA-3.0
Organizations Cal Poly Humboldt
Derivative of CCAT greenshed west wall
Language English (en)
Related 0 subpages, 4 pages link here
Impact 165 page views
Created April 22, 2014 by Justine Cook
Modified January 29, 2024 by Felipe Schenone
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