The hardness and low porosity of the cement plaster is incompatible with adobe, since it does not allow it to transpire moisture or "breathe." Testing of the adobe in the Peregrine Chapel revealed high moisture content, especially in the bottom two courses, where there was loss of cohesive strength throughout the width of the walls.

The Conservation Team removed the cement plaster from all exterior surfaces and replaced it with a softer, more compatible lime plaster, which was finished with a pigmented limewash formulated to complement the existing east wall of the Serra Chapel.

Following removal of the cement coating, the underlying adobe was assessed for strength and integrity.

Loose and delaminated material was removed, while severely deteriorated adobe was replaced with new blocks.

A trench was dug around the perimeter of the Peregrine Chapel in order to install a French drainage system, which will re-direct sub-surface soil water away from the building.

Wooden components of the roof system were in poor condition; the ends of the sheathing were close to failure, as were some of the rafter tails and beams. Much of the damage was caused by termite activity and, to a lesser extent, water infiltration.

Most of the existing historic wood was retained and repaired with an epoxy resin. Where damage of wooden components was extensive, replacement was necessary.

The Conservation Team matched the new wooden elements in species as well as in existing shapes and profiles. In order to keep the roof water-tight, a new waterproofing membrane was installed and broken or missing tiles were replaced.