Special Finishing and maintaining of wooden exterior walls

TO FINISH OR NOT?

OPTIONS WITH THE DIVERSE WOOD SORTS

Photo – Chimiver

Wooden walls are exposed mercilessly to increasingly fluctuating weather conditions, certainly in our part of the world. Therefore, those who opt for wooden wall cladding must ensure that the wall is not only finished, but also that it is given the necessary maintenance afterwards.

If we look at terraces, we know that not all wood sorts necessarily have to be finished. The question is whether not this also applies to wall cladding. Does it always have to be finished per se?

Which wood sorts?

According to specialists, some wood sorts can also be exposed to the open air (and therefore to the weather and UV rays). In this case we are talking mainly about western red cedar, douglas spruce, and larch. Since this wood originates from the heart wood of the tree, it is absolutely essential to use only planks with no sap to ensure the durability of the structure.

And so, some sorts show good external resistance before the fitting after a pre-treatment in the factory. Here, we are talking about sorts such as maritime pine (after treatment in an autoclave), robinia (false acacia), and certain European hard sorts such as oak, ash, horse chestnut, or poplar, after a heat treatment. You notice here that the original wood sort shade changes to some extent after this treatment (e.g. poplar changes from white to ‘light chocolate’ and oak takes on a dark brown shade like that of ipe), something with commercial benefits since the assortment is diversified and it becomes possible to raise the value of local sorts which are sometimes undervalued. Finally, pine, larch, and douglas spruce can be treated thermally, resulting in considerable technical benefits.

Ageing

Mechanical resistance doesn’t mean that the wood doesn’t age. Each sort of wood which is exposed to UV light will change in colour to some extent, depending on the sort, the quality of the wood (presence or absence of sap), and the exposure. The architect and/or the client sometimes strive for a slight ageing of the structure, but, understandably, they don’t react enthusiastically to darkening (the result of the penetration of blue fungi on non-resistant and unprotected sorts). Remember that in the vast majority of cases clients want stability in the original wood colour. The fact is that in many cases they choose a sort for its colour and it’s normal to want to preserve it, even if a certain patina is accepted or even desired. Don’t forget, too, that lots of sorts used for outdoor furnishing cannot be glazed durably (such as larch or douglas spruce or red cedar not at all).

Maintenance frequency

When the wooden wall is finished, all systems also have to be maintained, obviously. You can assume the following: glazes (six to eight years before

maintenance),saturation agents (two to four years, depending on the chosen quality), and anti-UV systems (four to five years). A good composition should make it possible to apply a maintenance coat without any other special preparation than dusting (especially the need to sandpaper before the application would be a major handicap).

For that matter, special products aren’t necessary. Protected wood can be maintained with the products or systems which were used originally. For wood protected in the factory, the manufacturer or supplier offers suitable maintenance products.

You don’t need to sand for renovation either. That’s why non-film impregnations and some glazes don’t need sanding (at least if they’re well composed and applied correctly) before the maintenance. It is simply recommended to clean the woodwork with a simple water spray (no high pressure!) in order to remove the deposited dust. Apply the maintenance product as soon as the wood is dry.

Photo – Blanchon

Source: Our thanks are due to the Blanchon Group.

What’s on the market ?

Chimiver

LIOS SUNDECK WOOD OIL Impregnator for outdoor wood LIOS Sundeck Wood Oil is an outdoor wood impregnator particularly recommended for the treatment of outdoor wooden floors (swimming pool edges, verandas, walkways), window and door frames, fences and walls made of wood. It contains natural and synthetic oils, with the addition of UV ray absorbers and special anti-ageing ingredients against the wood decay. It doesn't crack. Also available in LIGHT version, which doesn't alterate the natural colour of wood, particularly indicated for the treatment of south-american species (i.e. IPÈ Lapacho, Tobaco etc.) and other similar types of outdoor woods painted in autoclave (usually green colour).

Osmo

Optimal coating for timber cladding – the choice is all yours More and more often, natural raw materials like wood are chosen for the cladding and decoration of house frontages. The demand for modern greys as well as for colourful accents on window shutters and wooden beams is increasing. Osmo offers various products to protect wood optimally. For a modern grey stained wood cladding, Osmo Natural Oil Woodstain in various shades of this colour is the optimal choice. Colour accents are added with Osmo Country Colour in different colour tones. By treating wood surfaces with Osmo products, optimal protection is achieved after two coats. With or without UV protection, matt or satin sheen – the choice is all yours; Osmo has the right choice of products.

RIGO Verffabriek

ROYL Olie Exterieur

The master oil makers of RIGO Verffabriek have been making ROYL floor oils from 100% vegetable oils for almost 40 years. ROYL Olie Exterieur was developed and added to the ROYL range for the protection of exterior wood. Just like ROYL OIL, Exterieur protects the wood from the inside out. Finishing your wood with ROYL Olie Exterieur will enhance its durability and longevity by impregnating and nourishing the wood, seeping deep into its pores and polymerising into a tough, dense protective layer inside the wood. ROYL Olie Exterieur gives wood a beautiful, highly water and dirt-resistant surface. ROYL Olie Exterieur can be tinted with separate colour pigments. Besides, adding a colour pigment will also protect the wood against aging caused by sunlight. ROYL Olie Exterieur comes in 24 authentic wood colours. Treat your wood regularly with ROYL Olie Exterieur for long-lasting protection and to prevent weathering. ROYL Olie Exterieur can be used for both vertical and horizontal surfaces.

Tover

Outdoor wood (cladding, windows, shutters, barriers, etc.) requires protection against the atmospheric agents to which it is constantly subjected; the sun, rain, frost but also moss and mold accelerate the process of aging and degradation. Tover offers a water-based impregnation product: waxed Xilocolor available in transparent and coloured versions (wood colours, white, black, dark green). This stain is applied by brush or spray in two coats. It does not turn yellow over time and compared to solvent-based products is extremely easy to renew as the product does not flake off. As long as you clean the surface and apply a new coat, no sanding is necessary. However, it is possible to further increase the resistance of the product by applying Xilolak water-based protective lacquer available in matt and glossy versions.