Repair, Maintenance and Refurbishment
From diagnosis to intervention
Repair and refurbishment follow diagnosis. You must know the repair hierarchy (prevent, maintain, repair, replace) and how to specify appropriate, compatible interventions.
Key concepts:
- Maintenance regimes: planned preventative maintenance (PPM) vs reactive; condition-based vs time-based.
- Compatibility: matching materials to the existing fabric (e.g., lime mortars for historic masonry, breathable finishes).
- Refurbishment risks: asbestos (survey before disturbance), hidden defects on strip-out, structural alterations and Building Regulations upgrades triggered by work.
- Conservation principles: minimum intervention, reversibility, like-for-like repair, recording before alteration.
Traps in questions
- Over-strong repairs: cement pointing or renders on historic fabric trap moisture and accelerate decay.
- Ignoring asbestos in pre-2000 buildings before refurbishment - a legal and safety trap.
- Assuming refurbishment is always cheaper than replacement; whole-life cost and disruption matter.
- Forgetting that alterations can trigger Building Regulations compliance for the whole element (e.g., thermal upgrade on a replaced roof).
Worked rule of thumb
Use the compatibility test: before specifying a repair, ask whether the new material is weaker, more permeable and more reversible than the existing. If not, reconsider. For historic fabric, default to lime-based, breathable and like-for-like.
Example: Repointing a soft-brick wall with cement mortar causes spalling; the correct repair is a weaker lime mortar, raked to a suitable depth, matching the original.