We use Lime mortar on our modern stone structure repairs and building work. Lime mortar has better properties than straight concrete mortar.
These qualities help structures withstand weathering and aging better than before. If your stonework has an ordinary concrete mortar between the stones, you will have probably noticed cracking, pitting and crumbling.
Over time, concrete struggles to maintain its hold. So there are a number of extra benefits for adding lime to mortar:
1. The lime mortar mix is more workable
By adding hydrated lime to the mortar mix, the mortar has a greater plasticity. This means that we find the mortar easier to work with and shape for an elegant finish.
By adding water to the lime mortar mix, this activates the calcium oxide in the lime. But this does not turn the mix into putty or a paste.
So the mix becomes more workable and less “slushy” which also helps keep the stones clean and the immediate area clean.
2. Sand and cement do not separate
The lime in the mortar allows the cement and sand mixture to remain strong. This is important to stop the mortar from crumbling over time.
So the lime-based mortar is able to withstand more from the harsh elements like freezing and heating. Mother Nature cannot yield her damaging erosion as easily.
3. Lime mortar has better waterproofing
Traditional concrete only mixes were prone to taking on moisture from the atmosphere. This caused the mortar to expand and contract as it heated and cooled.
Also the water in the mortar would be susceptible to freezing. All this would mean your mortar, over time, would crumble.
Lime mortar reduces this water intake and reduces the chances of crumbling. So your new lime pointing will last longer from the effects of moisture.
4. Shrink cracking is eliminated or minimized
As the mortar with lime has greater waterproofing, this has the added bonus of withstanding shrink cracking. As mortar expands and shrinks due to the freezing and heating of moisture, the mortar will crack over time as it shrinks back down.
This cracking can spread as more moisture soaks into the mortar, which will eventually lead to stones moving and they will eventually fall.
So lime helps maintain the integrity of your new stone structures for many years to come.
What does this all mean?
For you, our valued potential customer, this means that your building work will be more durable to weathering and aging. Your structure will be stronger and have a seamless fit within your original stones.
Hence, your investment will have a better longevity and nicer appearance than before. You will have greater peace of mind.
You will not have to worry about future issues for many decades to come. Hence why we always use lime mortar.