Lime Mortar
Bricks Fix WA specialises in limestone repair, mortar repointing and heritage brickwork restoration across Perth, Fremantle, and Western Australia. In this guide, we explain why lime mortar is essential for historic and coastal buildings, when to use it, and how to choose the right type for the job.
History of Lime in Western Australia
Lime mortar has been a key building material in Western Australias colonial history, particularly in heritage structures like:
Fremantle Prison
The Perth Mint
Historic limestone buildings in Fremantle and East Perth
Early builders used lime from local limestone, producing breathable, flexible mortars that are still protecting walls over a century later.
Where Lime Comes From
Locally quarried limestone (burnt to make quicklime)
Imported Natural Hydraulic Lime (NHL) from Europe (used for restoration work)
Suppliers include Lime WA Inc, Saint-Astier, and WA Limestone.
Types of Lime for Heritage Brickwork
1. Lime Putty (Non-Hydraulic)
Made by slaking quicklime in water
Carbonation set absorbs CO from the air to harden
Ideal for historic lime rendering and repointing
2. Natural Hydraulic Lime (NHL)
Reacts with water to set (hydraulic set)
Comes in different strengths:
- NHL 2 Soft (interior or sheltered work)
- NHL 3.5 General-purpose external repairs
- NHL 5 Stronger, for exposed and marine environments
3. Hydrated Lime (Builders Lime)
Often sold in bags at Bunnings
Not suitable on its own for heritage work
Sometimes added to cement but not a substitute for lime mortar
Lime vs Cement Mortar: Why Lime is Better
Lime is the correct material for old brickwork and coastal homes.
Advantages of Lime Mortar:
Breathable: Allows moisture to escape
Flexible: Prevents cracks caused by building movement
Self-healing: Microcracks reseal naturally
Softer than bricks: Prevents damage to heritage masonry
Why You Should Never Use Cement Over Lime
Traps moisture, leading to rising damp
Causes bricks to spall and crumble
Creates rigid, incompatible joints
Can cause long-term structural damage
Coastal Brickwork: Lime Mortar Near the Sea
In suburbs like Fremantle, Cottesloe, and Rockingham, salt damage is common. Lime mortar is perfect because it:
Resists salt efflorescence
Allows walls to breathe and dry out
Matches the softness of limestone and heritage bricks
Bricklaying, Repointing & Restoration with Lime
At Bricks Fix WA, we use lime mortar for:
Repointing historic brickwork
Restoring lime render on limestone walls
New builds using traditional techniques
Heritage-listed site repairs
Projects we've completed with NHL and lime putty include:
Fremantle Prison restoration
Perth Mint conservation
Heritage repointing across Subiaco, Albany, and Perth CBD
Does Lime Mortar Need to Be Replaced?
Yes, but lime mortar is designed to weather naturally over decades. It:
Wears down before bricks do (sacrificial)
May need replacing after 80 to 100 years
Is easier to repair than cement joints
Lime repointing restores your walls strength and breathability without harming original materials.
How We Mix Lime Mortar at Bricks Fix WA
Every job is unique, but here's how we typically mix mortar:
NHL mix: 1 part NHL 3.5 or NHL 5 to 2.53 parts sand
Lime putty mix: Matured for 3+ months, fine washed sand
Additives: Sometimes we use pozzolans for faster set or strength
Colours are carefully matched to the original mortar for invisible repairs.
Lime Safety & Storage
Lime is alkaline and must be handled with care:
Always wear gloves, goggles, and a mask
Avoid contact with skin and eyes
Keep bags sealed and dry
Let lime putty mature in airtight tubs
We follow strict safety guidelines to protect workers and buildings.
Storage Tips for Tradesmen & DIYers
If you're storing lime for later use:
Keep NHL in a cool, dry area
Use within 6 months of opening (ideally)
Lime putty can last years if kept airtight and covered with water
Final Words
Lime isn't old-fashioned if it's just done properly. Using the correct lime mortar protects your building, keeps it breathing, and ensures long-term integrity.
Whether you're restoring a Federation-era home, a limestone cottage, or repointing a heritage wall, Bricks Fix WA has the skill and experience to do it right.
Need Help With Lime Mortar or Heritage Repointing?
Get in touch with Bricks Fix WA today:
Heritage Specialists
Lime Repointing Experts
Serving Perth, Fremantle, and Regional WA