We’ve talked in detail how the profile of external cladding effects the appearance of a garden office, but your choice of cladding material will also have a significant impact on the buildings appearance.
As well as having an aesthetic influence, your choice of external cladding material will also effect the amount of on going maintenance the garden office will need.
The most common material used for garden office cladding is wood, but this obviously comes in different grades of durability, and as low maintenance garden offices have become popular, other cladding materials such as WPC and colour coated steel have appeared in the market.
Properties of a durable cladding
A good external cladding for a garden office will not only protect the building from the ingress of moisture, but be durable to rot, insect and fungal attack. It will also have a durability towards UV light. Protection from these risks will create a longer lasting finish, that needs less on going maintenance.
Some cladding materials have a natural durability to the risks outlined above, whilst others can be easily treated to protect them, and finally you have the option of choosing a engineered product which have been designed to have a long maintenance free lifespan.
Common woods used in external cladding
The entry level timber cladding used on garden offices is pine cladding, in its natural state it is a honey colour. It machines easily so can be used for all profiles of cladding.
Pine cladding does need protection against rot, insect and fungal attack as well as protection from UV-light, as in its natural state its not a durable cladding, there are a few key ways of doing this:
The most basic form of protection is to apply a paint or stain to the wood, this will protect the wood from UV-light, which if left untreated will turn the wood silver.
Rot and fungal and insect attack are a big concern with timber cladding’s and normally pine cladding will be treated against these attacks. The best way of doing this is in factory conditions where the wood is impregnated with preservative at high pressure. This treatment is available in clear finishes which allow the natural colour of the wood to show through, or if the Tanalised treatment system is used the wood will have a greenish tint. Some suppliers will apply preservative by brush, whilst this is better than nothing it won’t penetrate into the wood in the same was as preservatives that are applied by pressure.
Another preservative treatment used on pine cladding is heat treatment, known as Thermowood. In this case the wood is heated at very high temperatures which preserves it. Thermowoods are often left without a decorative finish, although they take them well, and weather to a silver colour over time, some people consider the weathering of Thermowoods more even than that seen on untreated pine.
Many pine clad garden offices are painted, which not only repels moisture, but offers a uniform colour – some people find the grain and knots in softwood cladding ‘busy’. People’s fear with painted garden office cladding is that it is going to need a lot of maintenance, and whilst it will require a repaint every 5 to 10 years – depending on the buildings exposure, garden office designers tend to choose paint finishes that have a long maintenance free lifespan, that will age well, with the surface biodegrading rather than flaking.
Western red cedar cladding is by far the most used material when it comes to garden office cladding. The reason for this is because it is a dimensionally stable wood, so won’t swell or shrink like other woods, it has a natural resistance to insect and fungal attack, and as a rule doesn’t need a decorative finish.
Cedar starts out a reddish brown colour, but with exposure will weather to a silver colour, whilst the silver looks lovely, it will have a dramatically different appearance from the new building, and in a sense ages a building.
If decided at the design stage you can preserve the natural redness by applying a oil which protects against UV-light, but this needs to really be applied before the wood is exposed, so if preserving the initial colour is important to you, think about it early on.
Cedar cladding needs non ferrous fixings, the resins in the wood can corrode other fixings which will weaken the fixing and stain the face of the wood, so check with your supplier that non ferrous fixings are used.
Larch is another wood that has a natural durability making it a good garden office cladding, this is thanks to the resins in the wood which make it resistant to rot and fungal attack.
Left untreated larch will weather to a silver grey colour. Larch cladding has visible knots which add character to the building.
Siberian larch is commonly used as garden office cladding, but if you are looking for a UK grown and sourced product then you might consider Scottish larch, this would be a particularly interesting choice if you are designing a eco friendly garden office, because its carbon footprint will be smaller than other cladding options.
Engineered Timber Cladding’s
Engineered woods have been used as garden office cladding’s from the early days. Exterior grade plywood has been used successfully on some of the most popular garden office ranges for more than a decade – this speaks well for its durability as a cladding.
It is important that an exterior grade plywood is chosen, as it has waterproof glues in the build up, if interior grade plywood is left outside it will swell and bulge, with the layers of wood coming apart.
Plywood cladding has a smooth finish, and is normally painted to give a more attractive decorative finish. As we mentioned above the paints chosen are designed for longevity, and depending on the exposure of the building will only need repainting every 5 to 10 years.
We are seeing MDF products being used as used as cladding on more and more garden office designs. Peoples first thought is that MDF is an interior product, and will not stand up to the rigors of external use, but external grade MDF’s are very durable thanks to the resins used in its production. MDF makes a very good cladding as it comes in large sheets, so there are few joints. Unfinished exterior grade MDF has a green hue, but its smooth surface takes paint finishes well.
Recycled boards made from waste materials are new addition to the list of garden office cladding options. We’ve seen boards made from recycled wood fibers mixed with resins used on garden offices. Other products are made from recycled plastics. In both instances large sheet materials are produced which have a smooth or wood grain finish. These boards are normally pre-coloured to further enhance their eco credentials, and have a long maintenance free lifespan.
Composite Plastic Cladding
Known as WPC wood plastic composite cladding has many of the visual qualities of natural wood, but with the durability of an engineered product. WPC comes in several popular profiles such as tongue & groove. Polymers and ground hardwoods are mixed together to create the boards. The boards stand up well against heat, cold, moisture and UV-light, and suppliers estimate a 50 year lifespan. WPC cladding’s come in a natural colour palette, from cedar colours to shades of grey through to black.
Metal cladding is used widely in industrial building, but we can only think of a couple garden office suppliers who use them. Metal cladding is a durable option, some brands come with 25 year maintenance free lifespans. Metal cladding normally takes the form of smooth steel sheets which have a coloured paint finish, which is baked on at high temperatures, often these finishes have a slight leather grain texture.
Some of the architects are using corrugated sheets as a finish for both the walls and roof of the building. They have taken inspiration for this from farm buildings and it looks rather sleek using just one material palette for the exterior of the building.
Cement Board Cladding
Over the last couple of years we have seen a trend for the use of cement board cladding on garden offices. Cement board cladding is very durable, rot and fungal attack resistant and low maintenance in the long term. It comes in traditional cladding profiles such as shiplap, and has a wood grain texture. It comes pre-finished in a wide range of colours. The durability and maintenance properties are one reason that cement board cladding is becoming popular as a garden office cladding, but the other reason is that it is a low combustible material.
The Building Regulations state that buildings sited within 1m of the boundary line need to be built from non-combustible materials, and cement board cladding helps a garden office comply with this ruling.
PVCu is not widely used as a garden office cladding material. Some suppliers use PVCu as a covering for corner posts of the building, as well as the fascia and soffit boards, but mix this with other wall cladding materials such as metal sheeting.
PVCu cladding is available though, often in shiplap or tongue & groove profiles. The colour palettes available are minimal, with often white, black or oak effect to choose from.