Terraces, sandstone and old brick buildings
Heritage Rising Damp Treatment
Old Buildings Need a Different Approach
Sydney’s terraces, cottages and sandstone buildings were built with soft bricks, lime mortar and damp courses of slate, lead, bitumen, or nothing at all. After a hundred years or more, many of those damp courses have cracked, corroded or been bridged by later works, and the walls start drawing up ground water.
Getting it wrong on an old building does real damage. Hard cement render and cement mortar trap moisture and salt, and push the damage into the soft brick and stone, which then spalls and crumbles away.
My quotes cover the inspection, DPC injection with Silonexx into the mortar bed, and repairs using materials that suit the original building.
Treating Heritage Walls
The new damp course is injected into the mortar joint, not the brick or stone, so the original fabric is left intact and the holes are repointed to match. Where salt damage has already started, the affected render or plaster is removed and replaced with a breathable, salt resistant system that works with the old wall instead of against it.
The old damp course matters too. Read about slate, lead and bitumen damp course failures.
Spalling brick and crumbling sandstone are often the first sign that salt is the real problem. Once the damp is stopped, the salt has to come out as well. See salt removal for spalling brick.
Heritage work I do:
- Rising damp diagnosis on terraces, cottages and sandstone buildings
- DPC injection into lime mortar beds
- Repointing injection holes to match
- Removing cement render that traps moisture
- Breathable, salt resistant render and plaster
- Salt removal from spalled brick and sandstone
If the building is heritage listed or in a conservation area, check with your council before any work starts. I can give you a written method statement to support the application.