Repair options, from the lightest touch upwards
Good stone conservation removes as little original material as possible. We work through the options in order:
- Mortar repair (plastic repair): cutting back the damaged area and building it up with a colour-matched, breathable lime-based mortar. Suitable for small losses.
- Indenting (Dutchman repair): cutting out the damaged section and letting in a new piece of matching stone, leaving the rest of the original unit in place.
- Full unit replacement: where the stone has lost structural integrity, using stone matched for type, colour and bed orientation.
- Pinning and consolidation: securing delaminating faces with stainless steel pins and, where appropriate, applying a consolidant to friable surfaces.
- Cramp replacement: cutting out corroded ferrous cramps and replacing them with stainless steel.
Choosing a cleaning method that does not damage the stone
Cleaning stone badly causes more harm than leaving it dirty. High-pressure water and abrasive methods can strip the surface skin and open the stone to faster decay.
We select the gentlest effective method for the substrate — DOFF cleaning using low-pressure superheated water, TORC or JOS swirling vortex systems for controlled removal, nebulous water misting for heavy sulphation crusts, or poultice systems for staining. We test on a small trial area first and agree the result with you before proceeding.
Listed buildings and conservation consents
A significant share of our stone work sits on listed or locally significant buildings. Our teams work alongside conservation officers and heritage consultants, and provide written method statements and material specifications to support consent applications.
Rope access has a practical advantage on heritage stone: it leaves the streetscape clear, and it puts no scaffold ties through the façade. On a stone elevation, every tie hole is a future repair.
Book a stone survey with RAIL
If your stone façade shows open joints, cracking, spalling, staining or delamination, contact RAIL for a site survey and a schedule of repairs.
