Delaminations

The repair of delaminations is designed to prevent further detachment of stone, to establish a cohesion between exfoliated layers, and to prevent the penetration of water. Whether an edge detachment or a full detachment (in single or multiple layers), conservation treatments are typically the same.

Loose stone particles and other debris in the void behind the delaminated layer are carefully removed using a low pressure air wand. When necessary, the interior is cleaned by flushing with a wetting solution.

For sandstones, to ensure adhesion of grout within the void interior, surfaces are treated with a consolidant before filling. After complete curing of the consolidant, a flowable grout pigmented to match stone is gravity fed or injected into the void. Grouting is done from the bottom up, using a temporary backer rod. With large voids, grouting is done in “lifts”.

Pouring pigmented grout into void caused by delamination.
For slates, open areas are filled at the top edge of the marker using a pigmented filler. Voids along the sides of the marker are left open to allow escape of any water that may enter.