"Chemical protection and correct construction design are inherent to any project with wood"


Fifty professionals related to wood attended the day 25 February, at the headquarters of the College official de Arquitectos Vasco-Navarro in Bilbao, to the technical conference convened by ANEPROMA to analyze the current state and perspectives of wood protection in construction.


The day, second of the cycle "The Tour of ANEPROMA", that the National Association of Wood Protection Companies wants to take to numerous Autonomous Communities of Spain, It aimed to show wood specifiers in construction the most relevant requirements and trends of wood protection, both in terms of construction design techniques and the diagnosis and prescription of preventive and curative treatments.


The conference was inaugurated by Benoit Jobbé-Duval and José Miguel Solís, President and Secretary General of ANEPROMA respectively, who emphasized the importance of correct design and adequate chemical protection of wooden elements in any new construction or rehabilitation project.


The protection of wood in new construction


Manuel Touza, technician of the CIS MADERA of Galicia, guided attendees on how to determine the correct chemical protection of each wood element, In accordance with current regulations.


"It is essential to understand wood to work with it," warned Manuel Touza.. Rotting fungi and certain larval insects threaten the natural durability of wood, mainly in its most sensitive part, The sapwood. Given the enormous variety of wood species and depending on the use that will be given to them, The right decision has to be made regarding its chemical protection".


The Technical Building Code (Cte) clearly sets out treatment options for the most commercial species, according to its natural durability, its degree of impregnability and the kind of use to which it will be destined in the work. "In the 90% of the situations the prescriber is going to face a kind of use 3 –says Manuel Touza-, I mean, with occasional or frequently wet wood, subdued on catwalks, facades or structures at a humidity higher than 20%. In the works it is usually used sapwood of conifers that, Although it has hardly any natural durability, is easy to impregnate and, therefore, to treat chemically". Also the CTE clearly classifies types and methods of wood protection: superficial, medium or deep.


The rapporteur warned about the necessary precautions to be taken during transport, Handling and assembly of wooden parts: "If we know or foresee that the wood will be exposed to moisture or contact with the ground for a while in any of these processes, It should be taken into account when determining the chemical treatment that will be given".


Manuel Touza also alluded to the abiotic agents that, although they do not affect the structural performance of wood, do harm your aesthetics. "Naturally there are also preventive and curative treatments for these situations".


Touza illustrated with significant examples how to increase the protection of wooden elements through constructive design. "Minimal design details can condition the performance of a construction," he warned..


Prescription of curative and preventive treatments on site


Oriol Munné, CIDEMCO-Tecnalia technician complemented Manuel Touza's presentation by explaining the process to be followed in the prescription of wood treatments in rehabilitation.


For Munné, It is essential to make a correct diagnosis of the health status of the wood affected by an attack of fungi or insects, To determine the bearing capacity of the structure, opt for its replacement or reinforcement for, In the latter case, Perform appropriate chemical treatment.


"Material is often held responsible for these problems," said the CIDEMCO spokesman., when in fact they usually come from design errors or the absence of preventive treatment".


In Spain there is the termite. It must be assumed that it is a threat to wooden structures in the building. In addition, Woodworm acts, whose presence causes greater alarm, Because the galleries through which the insects come out are visible, although they are much less of a concern than termite.


"Identified pathologies, They should be located and the degree of section of wood concerned assessed., to calculate its structural benefits, Munné said.. From there, We will prescribe a curative treatment, if there is an active attack of xylophages, or a preventive one, if we expect it".


To conclude, The rapporteur insisted on the importance of using a product with quality certification and respecting the manufacturer's recommendations regarding dosage and method of application. "Without ever forgetting that using treated wood in the work is always much cheaper than rehabilitating a structure".


Faced with enormous growth potential in new construction and rehabilitation, wood is once again exposed to success or failure in the market. The CTE determines that its correct chemical treatment and constructive design are complementary. ANEPROMA and prestigious technology centers in Spain such as CIDEMCO or AITIM are at the service of architects who trust and believe in this material as the most convenient to carry out their projects.