Exterior cladding is a protective layer of materials that separates a building's structure and interior from exterior elements, such as weather and sound. The exterior cladding is often not one material but an assembly of materials, and each material has its own importance in blocking exterior conditions. For example, a contemporary house will have an exterior veneer of cladding or brick, a moisture resistant plastic wrap, insulation and a vapour barrier to protect the interior.
Water is often considered the hardest element to defend against on a structure. Moisture is repelled using siding, waterproof membranes, weeps, sealant, weather- striping and flashing. The cladding or external finish is the first line of defence and is usually the most important element. The membrane, sealant, flashing, etc., protect the structure from any moisture that penetrates the cladding.
Exterior cladding protects a structure from temperature extremes and variations by isolating the interior from the exterior along with a cavity and insulation. Rigid insulation, built-up layers of material, and double-glazing protect the interior from exterior temperatures by creating thermal gaps that do not allow the temperatures to be conducted through the cladding, bridging exterior temperatures to interior temperatures.
The building's structure and interior are shielded from the wind by the exterior cladding. To avoid damage to the cladding, the materials are redundantly and securely fastened to the structure, while allowing minimal movement by the wind. The method of fastening the cladding to the structure is especially important in areas with high winds and cladding must always be considered in the site-specific *structural calculations and thermal design of the subject building.
Exterior cladding deters damage and deterioration from the sun and ultraviolet waves. A structure's exterior elements must be able to resist the harmful effects of the sun. Otherwise, the failing material will provide access to the interior for moisture and tem- perature. Many plastic and wood products are not appropriate for exterior cladding be- cause they can degrade quickly when exposed to the sun.
Many contemporary cladding systems are novel and provide protection from the exterior with a thin skin. Modern systems such as aluminium and glass architectural glazing can insulate and shade a building as well as traditional masonry and wood systems. Other cladding systems are similar to screens, able to filter out the wind and sun, but allowing air to flow through the structure's skin. Eco products are not always suitable as grading, drying and preserving may not be possible. Many new systems require specialist installation and can be very expensive in the long-run*Structural Calculations Are an in depth investigation of all the components that are to be used in or on a building-see page 4
Timber cladding provides a highly attractive and durable external finish which is a wholly ecological choice as it is renewable, reusable, biodegradable and requires minimal embodied energy from forest to site.
For years we have used different types of timber for cladding buildings with different results and life-spans The most economical option is an imported sustainable Redwood that has been grown in a cold climate, harvested from managed plantations and sent to the end user on a certified chain of custody such as FSC approved. It is however imperative that any timbers are treated with a water-born vacuum impregnated preservative prior to use. Tanalith (Copper) and Creosote are no longer an acceptable method of preserving external timbers that do not have ground contact.
Other popular cladding timbers are Larch and Western Red Cedar both of which have a longer lifespan that Redwood but are around 40% more expensive.
To day in a age where we are all ecologically aware of the irreparable damage to forests new technology has enabled us to supply sustainable softwoods that have been modified to raise them to the same durability level as Mahogany and Oak but at a fraction of the cost.
ThermoWood has become a very popular choice for many external applications which starts life as Pine/Spruce/Fir. ThermoWood® is produced by heat treating Finnish grown pine and spruce to temperatures in excess of 200 degrees centigrade. During the heat treatment, chemical and structural changes occur within the timber which alter and improve some of its basic characteristics. The resulting product is an altogether more durable and stable timber, an ideal cladding material for use in exposed areas such as external walls. The finished colour of ThermoWood-D (pine) is affected by the treatment temperature and time. The higher the temperature the darker the appearance.
Accoya Accoya® wood also starts life as a sustainable softwood and undergoes an acid modification process from the surface to the core and has measurable consistency throughout. The result is a durable, stable and beautiful material that won’t rot, twist, warp or shrink. Think of Accoya wood as having the performance characteristics of the most durable tropical hardwoods.
Iroko Ipe & Garapa Etc South America & Africa supply a host of very dense hardwood timbers that are extremely durable and will provide a long life. You should be sure that these timbers have entered the UK legally and have been certified for sale by the exporting governments.
Composite Fibre and UPVC are an alternative to timber and many are supplied in a range of colours and finishes. They can be expensive if they require specialist installation but are usually maintenance free.
Profiles Most of the above are available in different profiles such as Shiplap, Waney & Featheredge, T & G & Half-log. The machine finish sizes vary but the minimum sizes should not be less than 19mm thick x 119mm wide. It is more economical to buy a profile and grade from a merchants stock although most will machine a batch with the profile of your choice
Cladding is easily installed as treated battens are fixed to the external timber frame @600mm centres (the wall panels have a vertical marker tape to show you where to nail)
The cladding of your choice is installed over the battens and this creates a 50mm clear air cavity so your building can breathe.
MOST TIMBER CLADDING can be installed vertically or horizontally
Structural calculations are a very complicated set of figures based on applied tests to prove that a building has the necessary integrity to meet the high demands of Building Regulations. Structural Calculations are prepared by professional chartered structural engineers and can easily run into 50-60 pages of information that are specific to the site and the exact building which will sit on it.
If the supplier of your proposed building can’t deliver a set of structural calculations specific to your address and relevant to the exact building you wish to purchase, then it is not likely to comply with the high quality of homes expected in UK and should be considered a temporary or garden building. We automatically supply Structural Calculations with every building we design and manufacture.
A thermal design dictates the U value (carbon emission) of each component in your new home and can be controlled by using a combination of several different types of insulation and membranes. The lower the U value the less fuel you use and the lower the carbon emissions (and your fuel bills). We will supply a thermal calculation and design on request.
Savolit wood wool boards consist of long wood fibres, stabilised by chemical impregnation and bound by cement-binding agent into a compact coherent structure. The mineralisation process strongly increases the fire resistance of wood wool.
The composition and performance of the boards make them ideal for many different applications in building constructions. Produced in accordance to standard EN 13168 (FIW München). Savolit boards are manufactured from 100% FSC certified wood