Green lime mortars show their true colours

Roger Shroff, sales and technical executive of Lime Technology Limited, explains the benefits to using increasingly popular lime mortar, both internally and externally.

One of the joys of embarking on the journey of becoming a self-builder has to be the thrill associated with researching and evaluating the spectrum of building materials and products that an individual, family or couple will ultimately specify to turn their dream into reality.

Internally the primary debating points usually centre on the all important kitchen, bathroom, wet room or, more specifically, wall and floor finishes, lighting and heating, and soft furnishings.

In relation to the exterior, it tends to be more heavyside products such as bricks, stonework, cladding, roof finishes, door and window furniture, and landscaping that come to the fore.

But choice today is not solely related to what many would term the main building ingredients. The same is equally true when it comes to the substance that is used to bind brick and stone-work together, both internally and externally – mortar. And here we are talking lime mortars.

A rainbow of colours 

As you are about to discover, not only do mortars tick all the boxes when it comes to green, environmental and technical credentials, you no longer have to stick the old Henry Ford adage of: “You can have any colour you want, providing it is black”, or as is often the case with mortars, beige or grey! Today it is all about being adventurous and occasionally bold. Above all, it centres on personal choice and a break from the norm should be encouraged among even the most conservative self-builder.

The spectrum of lime mortar colours available today is impressive. In essence they range not only from a variety of shades of blacks to grey, beige to buffs and creams to vanillas, it is quite feasible for a customer to ask a supplier to create a bespoke colour match. Such is the sophistication of today’s blending and manufacturing process. Indeed many suppliers are seeking to raise the bar further by increasing the romantic appeal of lime-based mortars.

As with any project, many would argue that its success often rests or falls on attention to detail. It is against this backdrop that the choice of lime-based mortar colour should be firmly on the radar, and for more reasons than one.

Green and technically proven

Not only do lime mortars come in a range of colours, they have a long and rich heritage here in the UK. They have been used for centuries and while it is only in the relatively recent past that cement-based mortars have populated the building and construction scene, it is certainly a case of what goes around comes around, as lime mortars are once again enjoying a marked revival. The difference this time around is, given that the green agenda is set to increase in significance, lime mortars are set for a long and successful renaissance.

So what makes it the preferred choice of their existing tribal following? Standing as an environmentally sensitive alternative to cement-based mortars, its soft, porous and flexible nature has long been universally recognised as being vital to maintaining the breathing performance of a building. Key benefits can be summarised as follows:

  • It uses less energy to produce
  • It reabsorbs some CO2 given off during the firing process when it sets
  • It reduces the need for expansion/movement joints
  • It’s durable, permeable and breathable
  • It allows masonry to be recycled when a building comes to the end of its life
  • The aesthetic attributes of lime mortar enhance the character of other materials used in construction, predominantly brick, stonework, lintels and door and window furniture
  • Workable for up to 24 hours, lime mortar is more porous than cement giving it an unrivalled breathability
  • Instead of trapping water into buildings and causing water ingress, they allow full vapour permeation that limits the risk of water damage to buildings

In summary, lime mortars are easy to work with, kind on the environment, incredibly flexible and an increasingly colourful bunch. No wonder they are set to become the best friend of an increasing army of self-builders.