Mortar joints carry hidden history — what binder was used, what aggregate, what cycle of repairs. Analysing them before repointing prevents the most damaging conservation mistake: incompatible repair mortar.
What analysis reveals
- Cement vs lime binder
- Hydraulic vs non-hydraulic lime
- Aggregate type, grading, colour
- Additives (clay, pozzolans)
- Mix ratio
- Historic repairs (different mortar phases visible)
Why match
- Visual continuity
- Mechanical compatibility (don't make harder than masonry)
- Breathability matching
- Frost resistance matched to bricks
The lab tests
- Acid digestion (separates aggregate from binder)
- Microscopy (binder type, additives)
- Sieve analysis (aggregate grading)
- Colour matching for replacement spec
Cost
- Basic analysis: R3,600–R7,000 per sample
- Comprehensive analysis with colour match: R8,000–R16,000 per sample
Sampling
2–3 samples typical for a domestic building, more for larger or historically complex. Take from inconspicuous areas. Conservation officer may specify sampling.
Specification output
Analysis report becomes the basis for repair mortar specification:
- NHL class
- Aggregate spec
- Mix ratio
- Colour expectation
MCFAR commissions mortar analysis on heritage projects.
Need expert engineering on your project?
MCFAR GROUP has been delivering structural engineering, building, and plumbing services since 1998. Talk to our team about your build, retrofit, or renovation.
Request a QuoteFrequently Asked Questions
Do I need lab analysis for repointing?
For heritage-heritage-listed buildings, recommended. For unlisted heritage, helpful but not essential — visual match by experienced specialist may suffice.
Can I just colour-match the mortar visually?
Colour is one component. Strength and breathability matter more — analysis confirms both.