Cob and Lime Specialists in Cornwall
- Published: 05 March 2020 05 March 2020
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We, Leslie Cornell Building Restoration Ltd, are Cob and Lime Specialists in Cornwall and it is very important to us that Historic Buildings in Cornwall are preserved and maintained with the utmost care and attention that they deserve. Our specialist knowledge of older buildings and the services we provide plays an important role within the Historic Built Environment as we only provide traditional and sympathetic methods of building restoration to ensure our Historic Buildings in Cornwall are correctly preserved for future generations.
Cob, stone and brick were traditionally used in the construction of older buildings and they need to be maintained with more considerate care than the more modern buildings we see today.
Cob is a mixture of clayey sub-soil, straw and water.
When prepared correctly it will generate a material that is durable, insulative, workable and a sustainable building medium.
For more information about Cob in Cornwall, please have a look at our What is Cob and Cob in Cornwall Website pages. If you would like more information about building with Cob, please have a look at our Constructing with Cob blog.
Stone is a hard and solid non-metallic compact mineral. It is a highly durable and versatile building material that has a high thermal mass.
For more information about building with stone, please have a look at our Stone Masonry Website page.
Brick is a small rectangular block typically made of fired or sun-dried clay. It is a strong and versatile building material that is insulative and has a great thermal mass.
For more information about bricks, please have a look at our Bricks in Cornwall blog.
The above materials are not as commonly used for building with today and so these Historic Buildings in Cornwall will have been constructed many years ago. Due to the length of time these buildings have been exposed to all types of weather, and where appropriate care and attention has not been given to them, there may be occasions where Cob Repairs or Stone/Brick Repairs are required.
Breathability is a term used to describe one of the core functions of traditional building materials. The material enables moisture to enter the structure but also allows it to escape again and Cob, stone and brick all have breathable characteristics. For more information about this process please have a look at our Breathability in Old Buildings blog.
If the breathability of these buildings becomes compromised, damp issues will almost certainly start to occur. There are many reasons why moisture (damp) can build up in the walls of a building, some of which are:
- Ineffective guttering, downpipes and/or facia boards
- Ineffective roofing components
- Ineffective or non-existent drainage
- External ground level/s being higher that internal ground level/s
- Vegetation and/or climbing plants/shrubs
One of the more common reasons, we see, for excessive levels of moisture in walls is non-breathable claddings, e.g. cement. Non-breathable materials allow moisture to enter the structure, but do not allow it to escape again. Our Lime services offer a traditional breathable method for damp limitation in Cornwall.
A Lime pointing application is introduced to act as a bedding between the stone or brick and helps to maintain the breathability of the building. This application can be used both externally and internally.
Lime render is usually introduced to the walls as a 3-coat application and helps to maintain the breathability of the building. During the Lime render process the character of the building can be maintained by picking out quoins, stones and lintels.
A Lime Bag-rub application covers the stone and fills the joints, whilst still showing the characteristics of the building. This too helps maintain the breathability of the building.
Lime plaster is introduced to the internal walls, usually as a 3-coat application, and helps to maintain the breathability of the building. This process follows the existing contours of the wall to enhance the building characteristics.
As well as inappropriate claddings, many readily available paints can trap moisture within the wall as they are an impermeable material. For internal and external painting on traditionally built walls we would always recommend using a Lime or Mineral Paint System as they are water vapour permeable, meaning they are breathable.
If you own an Historic Building in Cornwall and are thinking of undertaking a project that requires our specialist help, please Contact Us.
For more photographs of the traditional and sympathetic restoration works we undertake, please have a look at the Gallery page on our Website.
Cob and Lime Specialists Cornwall – Historic Building Specialists Cornwall – Breathability Specialists Cornwall – Damp Specialists Cornwall