ARTICLE FOR GUERNSEY PRESS 2005

In recent years, the environmental impact of modern building techniques and products has caused a great deal of concern. Synthetic paints, plastics and plasters have led to indoor pollution on a staggering scale and the number of allergies is at an all time high. Statistics show that there is commonly 10 times more pollution inside a modern home than outside, due to the materials that are used in its construction and maintenance. To address problems such as these, a local company called Limeworks was set up five years ago by Leigh Le Noury.

Limeworks sells a wide range of natural products for use in the construction, restoration and maintenance of all types of buildings. The company was initially set up to sell natural hydraulic lime from a company called St Astier, from the Bordeaux region of France. As a building material, lime was commonly only associated with the restoration of historic buildings, but nowadays St Astier natural hydraulic lime is used extensively in new-build because of its flexibility, breathability and environmental benefits.

Since Limeworks began in 1998 literally hundreds of properties have benefited from the use of natural building and decorating materials. Many local churches ie; Forest, St Saviours, Castel, Vale, St Sampsons and St Peters

Leigh explains that there is a dynamic relationship between the health of buildings, people and their natural environment: “If we use environmentally damaging products in construction work, we affect the environment, the health of people and the health of buildings. Ecological products, by contrast, work with nature to enhance health, as well as providing social and cultural benefits to individuals, communities and society at large.”

The control of moisture in buildings is one example of how conventional and ecological approaches can differ. Excess moisture leads to the development of bacteria and mould that affects both human and building health. The conventional approach is to use synthetic barriers, mechanical extraction, pesticides, fungicides and impervious materials all of which can be damaging to the natural environment.

From a building ecology point of view, Leigh considers that a better approach is to maximise the fabric’s ability to absorb and regulate moisture by using natural hydraulic lime that allows the building to breathe. Leigh explains: “This eliminates condensation and draws moisture away from wooden windows, lintels and beams, thereby protecting them. Unlike cement and gypsum, natural hydraulic lime does not contain harmful salts, which so often damage interior and exterior paint finishes.”

Lime plasters take on the colour of the sands used, and so create beautiful finishes without the need for additional decoration. However, they can also be decorated with a wonderful array of colours by blending natural earth pigments with traditional lime washes. The lime wash is made from lime putty slaked by Leigh on the island.

Wood is a prominent feature in many natural houses and Limeworks stocks a top quality range of wood finishes from OSMO. All the products are made from a blend of natural oils and waxes to protect the wood and enhance its natural beauty. There is a wide range of colours available, as well as natural clear oils. Cleaning products such as wood soap and wax cleaners are also available.

In the last year, Leigh has extended his range of natural products, through a partnership with UK company, Natural Building Technologies. They provide ‘NBT Paints’ to complement the St Astier range, but they are also pioneers in many new products for the construction of ‘eco-friendly’ buildings, such as natural wool insulation, earth plasters and reed boards and mats.

Earth Products

These products are suitable for both historic building repairs and for new build applications. They are extremely low energy materials, from sustainable resources and are entirely healthy. They are eminently suitable for breathing constructions and have been in use for thousands of years.

In the UK there are hundreds of thousands of buildings with earth in their construction. Many of them date from the middle ages and are still functioning well. Earth products are easy and pleasant to use for the professional and the amateur alike. They are capable of creating a stunning appearance, are durable and easily maintained.

· Self-coloured earth plasters are available in bags and are mixed with water in a conventional mixer. They are mainly used for interior work.

· Clay boards are an alternative to plaster board. They provide all the environmental and building health qualities of lath and plaster or daub, but at much less cost and much quicker.

· Earth blocks are a natural alternative to concrete blocks and can be used internally or externally with adequate protection. They can be finished by plastering with earth or lime.

Reed Products

Reed products are particularly suitable for timber frame buildings. Reed is itself a historic building material which was commonly used in lowland areas for ceilings, walls and suspended lime and earth floors. The modern reed mats and boards continue a tradition that uses natural breathing materials, but is adapted to today’s market.

The boards and mats are made from natural reeds laid parallel and tightly bound using thin zinc wire. They are for both internal and external use as render carrier for walls and ceilings and can be used against a solid background, or over studs or joists. They can all accommodate the curves and irregularities common in historic and character buildings, and can be used as an economic and effective alternative to wooden or metal lath.

· Reed mats are suitable for ceiling lath substitute and supported wall lath.

· Reed boards are particularly suitable for providing insulation to breathing buildings, both externally and internally with comparatively little cost or loss of space.

Natural Insulation

With the present day concern to improve the thermal performance of old buildings, it is essential that compatible insulation systems are used. Unlike most common synthetic insulation material, natural insulation is properly compatible with historic building fabric. It has the same breathing qualities as traditional materials such as timber, earth, and lime.

· Wool insulation comes from a fully renewable resource. It acts to prevent condensation by maintaining the temperature above the dew-point in damp conditions. Unlike some other forms of insulation, it is harmless and can be installed without gloves or protective clothing. It is not irritating to the skin, eyes or respiratory tract. The necessary insect proofing and fire resistance rating is achieved by the inclusion of naturally derived additives and so any fibres which happen to reach the living space will prevent no hazard to health.

· Wood fibre thermal boards are for internal and external use and acoustic insulation on walls and ceilings. They can be used against a solid background or over studs and can receive lime or earth-based renders.

· Expanded clay aggregates are ideal for use as part of a breathing floor system, for example as an insulating sub-base beneath ground floors or as a light weight aggregate in lime concrete slabs. They consist of lightweight, porous ceramic granules formed by expanding special clays at high temperatures. In bulk, this insulation is free-draining and has good load-bearing and thermal qualities.

Natural Paints

Today’s natural paints have developed from the historic paint tradition to take account of the needs of the modern user, the building and the natural environment. They are healthy, easy to use and have excellent technical qualities.

· Casein paint has been around for 5,000 years, it is extraordinarily durable and, properly maintained, can last for several generations. It is coloured by adding pigments and gives a soft matt chalky finish.

· Keim silicate masonry paint has excellent covering properties. It is breathable and exceptionally durable and can assist in regulating the humidity of the internal environment. Externally it is especially suitable for work on historic buildings. Pigments are used to add colour.

· Historic emulsion is for internal use only and is tinted with natural earth pigments. It has excellent covering properties, is wipeable, anti-static and virtually non-drip and is free of harmful solvents.

· Natural wood finishes are unlike other wood paints which form a plastic like film over the surface, these are based on natural plant oils and waxes which penetrate into the wood, allowing the wood to breathe. 2 coats is all that’s needed.

 

Article for The Guernsey Builder;

The great lime revival

The use of hydraulic and non hydraulic lime mortars, plasters and renders, have been in common practice throughout most of the world for at least 2500 years and probably well in excess of 5000 years. The Romans, Greeks and Egyptians made great use of this natural cement by using it as the principal mortar in there bridges, harbour works and great buildings. Hydraulic lime was of great use as it was able to be used under water and could be made into varying strengths depending on the requirements of the architect. Many examples of lime can still be seen today, standing testament to the outstanding durability of this natural binder.

In Guernsey the earliest recorded use of lime was in the 13^th century in the construction of our churches. It might well of been used in small amounts by the Romans when they were here as they were the first people to introduce it to the United Kingdom but unfortunately no Roman buildings have survived in Guernsey.

As Guernsey has no natural source of lime it had to be imported. In the 18^th and 19^th century it arrived as ballast in ships, unloaded and then reloaded with local granite to be exported to the UK. It is not known how we sourced our lime mortars before this period, but one possible way would have been to burn our local sea shells. This might seem strange but sea shells are a very pure form of calcium carbonate and could have been collected off the beach, or saved from the populations dinner plates!

This would of produced quite a weak non hydraulic lime, which could have been used for internal plaster and lime washes. If a stronger lime was required then the addition of crushed local brick could have been added to produce an artificial hydraulic lime. This type of lime would have had many uses from external renders and pointing which protected the earth mortar from the elements, to durable lime concrete floors.

Lime has been making a strong come back in recent years after the realisation by many conservation groups including English Heritage, Historic Scotland, The Society for the Protection of Ancient Buildings and The National Trust of the damage caused by Portland cement.

The problem with cement is that it is too hard and dense, so it cracks when the building moves. These fine cracks allow moisture into the wall where it is unable to escape causing salts to become activated so damaging interior paint and plaster. Beams and lintels that have been there for centuries all of a sudden start rotting, all because we try to “seal” our home which is the worst possible thing you can do as this also creates condensation and mould. By using these modern materials you are in effect living in a polythene bag!

When our ancestors built houses they used natural materials - earth, wood, stone and hydraulic lime. All these materials are breathable; in other words they do not trap moisture. These buildings have been around for hundreds of years, moving and breathing with the environment and the changes in season. As soon as you put an impermeable coating on a solid wall building, i.e. cement or modern masonry/emulsion paints, then you stop the ability of that wall to breathe which is why today we have so many problems with our old buildings.

Hydraulic lime sets just like ordinary portland cement but is a natural building material. During curing lime re-absorbs the CO2 given off in its production, so making it more ecological. Its ability to regulate the humidity of the internal environment and eliminate condensation have a great benefit to human health and the building itself. Lintels, beams and wooden windows are also protected as the natural hydraulic lime draws the moisture away from the wood, thereby protecting it. Natural hydraulic lime does not contain harmful salts unlike cement and gypsum. You can even mix it with sea water without affecting its strength. Lime takes on the colour of the sand used so creating beautiful coloured render/plasters. It is particularly beneficial in a marine environment as it does not contain gypsum, which reacts badly in a salty & damp atmosphere.

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• Elasticity, essential for building without construction joints.
• Permeability, great benefit to the living environment.
• Salt resistant, Sulphate attack and alkali-silica reactions impossible.
• Autogenous (the ability to self heal).
• Available in a range of colours.
• Natural antisceptic.

Limeworks was established in 1998 to supply natural hydraulic lime to the building industry and help undo the damage caused by portland cement and synthetic paints to our historic buildings. These natural building materials are now produced with modern technology giving a consistent product expected in todays world. They are produced in 3 strengths so offering the specifier different choices for a given situation.

Since then we have added many other products to our range all of which are natural, breathable, healthy, ecological and all out perform modern equivalents in many ways.

Since 1998 we have been involved in many high profile and award winning projects including L’Escargot (Architect-Andrew Dyke) which has a natural hydraulic lime render and paint finish and won a design award. The same year Les Fries Barn which has been totally restored using natural hydraulic lime and natural oil paints, was highly commended. Recently La Concha (Architect Jamie Falla) won the latest design award. This has been renovated using lime. Limeworks products were also used in the repairs to St Appolline Chapel where the use of Portland cement for the external pointing was having a detrimental effect on the 14^th century frescoe.

St James has benefited from Limeworks natural products including the external paint finish, plaster and render repairs and the bedding of the portland stone driveway. By bedding the Portland stone driveway in hydraulic lime it will be possible in the future to move or reuse these beautiful stones without destroying them, so making them recyclable in the process.

Limeworks and the Natural House Shop offer a large range of alternative building products many of which have been in use on the continent for many years. As governments become increasingly aware of global warming due to CO2 emisions it is increasingly important that the building industry becomes more ecological in its approach to building. By using low energy re-cyclable and re-newable materials for natural paints which are healthy, breathable and tinted with natural earth pigments giving unsurpassed colour and vibrancy. Many other products are available.