Construction Systems
Everything You Need to Know About Eco-Friendly Timber Homes
Today, we would like to discuss how to build eco-friendly timber homes and their viability in a country where construction has traditionally used brick or concrete.
While it is true that wood is a traditional building material in Northern Europe, where tall and slender fir trees are available for construction, we have often discussed the availability of local timber in Catalan forests for building eco-friendly wooden houses in Barcelona and, of course, in other provinces.
A few months ago, we visited a company dedicated to building eco-friendly timber homes. They started their activity producing wood for construction and had expanded their business to specialize in building wooden houses where, they told us, it was very easy, using a sealed and very well-insulated construction system, to achieve adequate comfort levels indoors. By the way, the company is called Fustes Sebastià and is located in the Catalan Pyrenees, in the town of Rialp.
If the house is built correctly, the interior temperature remains so stable that we achieve a house that does not require heating.
But let’s look in detail at what we should consider when building eco-friendly timber homes:
What should we know to build eco-friendly timber homes?
One of our clients’ biggest concerns is whether a wooden house is as durable as one made of brick or concrete, as they worry about threats such as fire or termite attacks.
And while it is true that wood is a natural and living material for which we must take precautions to avoid future problems, in Catalonia and other provinces, we have excellent construction companies that treat wood following ancestral knowledge and carefully manage every detail of the process to achieve durable wood that they themselves guarantee for life.
How are eco-friendly timber homes built?
The first step to building these homes will, of course, be finding a suitable plot of land and contacting an architect specializing in timber house construction. Since we have already covered these topics in depth in previous articles on this blog, and they are also valid for eco-friendly timber homes, we refer you to them.
– How to find land to build a house?
– Steps to build an eco-friendly house
Thus, we want to focus on the durability of wood for building eco-friendly homes in Barcelona: what kind of wood should be used for construction to achieve a house that lasts forever and does not present any problems with humidity or insect attacks?
Well, let’s go step by step. A good eco-friendly timber home begins in the forest. When and how we cut the wood will be a key factor in ensuring its durability, but immediately afterward, the treatments applied will determine its structural and biological resistance.
Wood for Eco-Friendly Homes
When do we cut the tree to extract wood from the forest?
This is part of traditional wisdom; if you ask any countryman when to cut a tree to obtain wood for construction, the answer will be unanimous: the tree should be felled after winter has passed, when there is no snow in the forests, and before summer begins.
Also, just before it snows, to be able to access the forest without problems, although this inconvenience only applies in Catalonia where forests are difficult to access. In Finland, for example, flat forests and advanced machinery allow timber to be felled even when there is snow in the forest.
And why is this?
Trees should not be felled in spring to avoid the sap that is actively flowing during the spring and summer months.
Furthermore, the tree should be cut when the moon is furthest from the earth, which is when the tree is inactive and has no sap. The specific moment would then be during a new moon (also called a dark moon), which is when we cannot see the moon.
Why is sap detrimental to wood intended for house construction?
Sap is detrimental to wood intended for house construction (structures and furniture) as well as wood intended for burning.
The amount of sap a tree contains determines its moisture content, and as we know, moisture is wood’s main enemy.
Drier winter wood will be easier to dry for construction use because it will not contain as much water.
What do we do to prevent insect attacks on wood intended for construction?
To prevent insect attacks on wood, it is necessary to remove the bark immediately after it arrives at the sawmill. This is necessary because insects are born between the bark and the trunk.
It’s not that the wood already contains insects, but it’s where they could settle first to extract the natural sugars that are their food.
But in addition to preventing insects, we want our wood for house construction, whether eco-friendly or not, to be as straight as possible and free of cracks.
How do we achieve straight, crack-free, and insect-resistant wood?
Well, let’s follow the process at the sawmill. The wood has arrived, and its bark has been removed. This wood can be stored for up to a year (traditionally, it was stored for one or several years to dry; nowadays, we have industrial dryers).
Once the bark is removed, the wood is sawn in half, longitudinally, to avoid the heartwood. Cracks originate from the heartwood, in the center of the trunk. Thus, if we saw the trunk in half, cracks no longer form.
The next step to obtain durable wood is drying.
As I mentioned, this process was traditionally done naturally, protecting the wood from rainwater and waiting several months or years before it could be used. Nowadays, we have drying kilns.
When wood arrives at the sawmill, it has around 60-80% moisture, and it must be sold with a moisture content of 17-20%.
How do we quickly reduce all this moisture?
In a drying kiln.
First, a water tank is filled, in which the log is submerged so that the wood stabilizes its moisture, and then it is introduced into a drying kiln, which is essentially a large sealed chamber with temperatures reaching 70-80 degrees Celsius. The drying process can last several days or even weeks, depending on the type of wood and the size of the logs.
What have we achieved?
After this process, we obtain wood that is:
– crack-free
– does not twist and remains straight
– free of insects because there is no longer any food (sugars present in the sap)
From this point, if we want to build eco-friendly timber homes that are also healthy, we must consider the type of protection for the wooden beams.
It should be noted that Spanish regulations mandatorily require:
– Applying an insecticide-fungicide treatment
– That wood for house construction has a 10-year warranty
But what happens after these ten years?
A house will last more than 10 years. For this reason, even if we are going to build eco-friendly timber homes, it is important to ensure that the wood comes from a reliable sawmill that guarantees an ideal felling, sawing, and drying process to ensure the wood’s durability.
Is it necessary to protect wood for building eco-friendly timber homes?
Although the CTE construction regulations require wood to be protected with chemical treatments that are eventually emitted into the indoor environment, if the client requests it, the sawmill does not apply chemical treatment to the wood.
We are very much in favor of this alternative, although it is true that there is still a long way to go in the field of indoor environmental health in our homes, and many clients are reluctant not to protect the structure.
As always, remember that if you are considering building eco-friendly timber homes, you can contact us.
In our studio, we work on eco-friendly timber home projects in Catalonia and throughout Spain, creating custom projects for all types of families and budgets.