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.
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.
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?
Ageing
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
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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
