In the media, the cause of moisture and mold damage is presented as a simple truth: the carelessness and incompetence of the builder. It is intellectual dishonesty to target a rather wide cause-and-effect chain on one party, of course the builders are not flawless either. During my career (RI 1977) I have been involved in building and renovating several public administration properties and here are a few considerations.
According to the standards, the buildings are designed for constant temperature conditions, with an indoor air temperature of approx. 21 degrees and ventilation on all the time. A large part of the problems would be eliminated if users took care of even these two basic things. The building is a complex technical entity, but no one seems to be responsible for the use and maintenance. The car maintenance instructions are followed.
In order to save energy, the ventilation is stopped and the temperatures are lowered for the night, weekends and holidays. Particles accumulate in the IV channels and machines, which partially flow back into the room air when the machines stop. At start-up, the moskas are dusted again. Contaminants do not move in and out of the filters as designed. Internal temperature changes cause the dew point to move in structures to places where condensation causes damage to the structures. Saving creates conditions for mold.
The public administration is surprisingly sensitive to go along with challenging, experimental and innovative solutions, despite the risks. The most famous example is probably the facade of Finlandia Hall. Solutions unsuitable for Finland are used in the shapes and materials of water roofs and facades. Any comments made by contractors about risks are not taken as true. If the designer keeps his head, especially the lay decision-makers will not believe the construction contractor. Even the planner may have requirements unsuitable for winter conditions. The accessibility with its slope may cause problems for the height of the floor in relation to the environment.
The Procurement Act governs public projects. A bid submitted contrary to the request for bids can be rejected despite the risks brought up, therefore the contractor should not even present sustainable solutions in the bid phase. Reasonable alternatives can be taken into account in private financing projects - property management is also often on a different level.
In school construction, it often happens that a decision is made on the construction project in the budget process, and at the same time that the new facilities must be ready next fall or, in a larger destination, the following fall. Clinging to the beginning of the semester destroys many projects already in the starting scaffolding. The legislator should definitely require a planned implementation schedule of the construction in connection with the building permit, with which the applicant for the permit shows that sufficient drying times have been reserved for the structures. A concrete rag can only dry in 24 hours, even if all employees work in three shifts. The schedules set by the customer sometimes even require implementation against concrete standards. Assigning "moisture consultants" to the construction site is almost a joke.
Two qualities have partly emerged for construction companies – the so-called in our own production, we try to choose schedules, structures and materials in such a way that complaints and warranty work do not arise, because it is the lifeblood of the company. In contract production, the customer defines the schedule, design solutions and materials, sometimes putting the contractors in a "forced gap". The ten-year liability of the General Terms and Conditions of the Construction Contract does not obligate the contractor to anything, if the plans drawn up by the customer are followed exactly. I've sometimes had to register a reservation about this kind of thing, so that our company can't be held responsible for an invalid solution afterwards.
The law on public procurement unfortunately leads to the fact that a cheap designer and a cheap implementer are chosen for public construction. As a rule, no other criterion is used in the selection than the price. You rarely get good for cheap.
I hope that the authorities and legislators could sometimes listen to those of us who have worked in the field for a long time without passion and without prejudice - something has certainly been learned that would be useful now and above all in the future.
Mikko Kurtti
Construction engineer, managing director
Rakennusliike M. Kurtti Oy
The text has also been published In Kauppalehti 24.4.2017.
The house built by M.Kurti for Taova in Kemi in 1997 had to be repaired 17 years after its completion. The leaks themselves started a good 10 years after completion.
"In order to save energy, the ventilation is stopped and the temperatures are lowered for the night, weekends and holidays." This is exactly what happens. Not even all the toxins in bad indoor air come from mold.
Add plastic and air conditioning ducts to Finnish construction in a damp and cold climate, and mold problems will become commercially viable. As far as I remember, I didn't even hear that there were mold problems in schools when ventilation took place in schools and hospitals through windows. In schools, the windows were opened during recess and closed when the recess was over. Now, long mechanical air conditioning ducts are good breeding grounds for mold problems, and that's the air the employees breathe, so something should be done. It probably has its share in the widely used plastics in wall structures. Plastic does not breathe like previously used cardboard materials, but collects moisture in structures and later mold.
How do all these reasons explain the water leaks of an award-winning building when it was new, or the danger of a new bridge collapsing, or the generally poor quality of the construction industry. Bad construction is bad construction, whatever the reason. If a reputable construction company considers that it cannot build a decent one, it should withdraw from the project.