At the time of the Discoveries, Portugal was one of the biggest western producers and exporters of hemp. The plant was used for ships' sails and ropes.
Today, hemp is starting to take its first steps in the construction sector. The first building to debut the innovation is the local accommodation Paraíso 331, located in Porto.
"The sustainability of the material and the fact that it is ecological [are some of the reasons that make hemp a new choice of material in the construction of houses]. We had also heard about its soundproofing qualities and that it was very good at thermal and acoustic terms", said, to SIC, the manager of the company Lovely Memories, João Santos.
Despite belonging to the same family, the hemp plant is a distant cousin of cannabis, that is, it does not have pharmaceutical purposes.
"Industrial hemp, let's call it that, is used to make clothes, civil construction, oils, for food. It is different from pharmacy hemp, there is no psychedelic associated with industrial hemp", explained, in an interview with SIC, the architect, Francisco Fonseca.
What distinguishes hemp block from traditional concrete
"It presents an alternative to non-structural materials, which are the insulating materials, the ceramic bricks, the cement blocks that we find in construction. Hemp is actually hemp concrete, the hemp block that is the only material in civil construction that complies with thermal, fire, acoustic regulations, in a single material in 25 cm or 23 cm of wall", added the architect.
"We are talking about a plant that reactivates, restructures deserted soils, poor soils and, therefore, has a very exuberant carbon capture", described Francisco Fonseca.
But, the investment is still 25% higher than traditional construction. This is because, for now, there is not enough production in Portugal. But two years ago, a company based in Alentejo decided to revive the market, based on the idea that you can build a house with walls made from nature.
"This year we are going to have 100 and a few hectares of national hemp plantation. It will be an experience for us to try to understand the profitability and the best way to do it so that they can collaborate with us in the future", said the operational director of Cânhamor.
From the hemp plant it is possible to remove fiber, flax and wood, the material that is of interest to build houses.
The first process is in a machine that crushes the plant. Then it goes to the mixer, where the wood is mixed with lime and clay. A dough that takes 10 minutes to be ready and that will then give rise to three blocks of hemp.
"It is the only vegetable fiber that has an absolutely surprising behavior with water, it does not lose mechanical characteristics in contact with water", explained the architect Francisco Fonseca.
Worldwide, the construction industry is responsible for 10% of global greenhouse gas emissions.
Source: SicNotícias
