WHY USE LIME MORTAR?
If you possess a home that was designed utilizing lime mortars it is really important to appreciate that the professionals who designed and built your house had knowledge of what lime could certainly do. Its breathability is an important element of the way the property copes with moisture from the ground, rain and from the activity of day-to-day lifestyles. Its ability to cope with movement is a fundamental aspect of the design of the property.
Buildings constructed with lime usually tend to be generally on much lighter footings than today’s sand/cement and concrete constructions.
They were generally built with a “Step foundation-footing" no more than 400mm below ground and were generally designed to move with the heave and fall of the land. This strategy is not shoddy or bad practice in any kind of way. It is not necessary to endeavor to maintain a building established with slaked lime mortar inflexible as lime can move without cracking.
Due to the fact that cement mortar minimizes the passage of moisture there will also be a localized build up of moisture in the lime construction leading to rapidly accelerating degeneration, recognized as “sick house syndrome".
Using modern plasters, cement renders and non breathable paints can lead to damp issues as they seal the walls not permitting them to breath.
If you have a period property experiencing from damp, cracking or timber decay, please consider that many of those problems are easily dealt with by allowing the building to function as it was designed to do. The long-term repercussions of using modern materials without due consideration on traditional buildings can surely be devastating and expensive. If you have a period property I would definitely always recommend using a skilled period building contractor.
If you have problems with rising damp, check the ground level outside, over time it may likely well have been raised. Examine the pointing to see if it is cracked, falling out, lifting or too hard, this will incite moisture levels to increase in the wall.
Check your air bricks (if you have any) are not obstructed.
Walking round your property when it’s raining, check the gutters are working and water is not pooling against the walls.
The Real Benefits Of Lime Mortar
Natural lime was used traditionally as a binder in mortars, renders and plasters up until the 19th century when Ordinary Portland Cement was introduced. Ironically, modern insight has revealed substantial benefits of natural lime over the modern cements that dominate the building industry today.
It is breathable (vapour permeable), absorbing and evaporating moisture coming from surrounding masonry. This also helps to safeguard the masonry, there is less risk of salt and frost deterioration.
It has a low modulus of elasticity. This means it is extremely flexible and allows for movement and thermal expansion.
It is softer than modern cement, a softer mortar will definitely not wear out the surrounding masonry over time. Bricks and stones are also reclaimed more easily if dismantled.
It is more eco-friendly, the lime manufacturing procedure produces less carbon dioxide than ordinary cement. Furthermore, it re-absorbs carbon dioxide thus lowering its carbon footprint even further.
Appealing traditional appearance, pale in colour. Natural limes have a tendency to reveal the colour and characteristics of the aggregate with which they’re mixed. This is a real benefit of using lime mortar.
Here at Brick Repointing UK Ltd we confidently carry out lime mortar expert works on a regular basis covering Hertfordshire, Bedfordshire, Buckinghamshire and North London.