Sewer pipelines and storm drains of most residential buildings and public buildings in Estonia have been in operation for over 30 years, constant contact with household chemicals and waste has led to their depreciation. In addition, in pig-iron pipelines, so-called fatigue cracks develop over time, usually occurring at joints or along the pipeline.
Repairing old pipelines no longer means tedious and costly destruction of walls and floors and earthworks. An alternative solution was a special material hardening under the influence of resins, which allows you to embed new pipes directly into the old pipeline. A photo: Terrat
What to do?
There is a solution: today, to replace both horizontal and vertical pipes, you do not need to break walls, floor or ceiling. The quick and clean method does not require cosmetic repairs after replacing pipes, saving both the money and the nerves of the owner of the building.
“The condition of the pipes in the building can be compared with human health: when do we go to the doctor? When faced with a problem. The average life span of a pipeline is between 40 and 50 years, and if your home is approaching such an anniversary, it's time to cast a critical eye on the pipes, ”says Elner Rannu, project manager at AS Terrat.
To assess the situation, of course, it will be necessary to conduct paid research, but it may turn out that the condition of the pipes is by no means so catastrophic, so the partnership or home owners can do nothing for another five years. “As a rule, partnerships are not inclined to prevent problems and the builders are called when the trouble is on the verge. However, Nordic insurance companies strictly require periodic renovation of pipelines, otherwise they do not pay insurance compensation for damage from leaks, ”says Rannu.
Impregnated with resins, the “stocking” was pushed with compressed air through a pipe in the basement to the roof, almost without entering the house. The pipeline hardens with steam heating. After curing, a new, completely waterproof pipe forms inside the old pipe. . A photo: Terrat
But the saddest situation, according to Rannu, is the case when people repair the basement, stairs, courtyard, terrace, and then it suddenly turns out that they forgot to change the pipes laid under the concrete floors and in the yard. The problem of blockages can be solved for some time using a pressure washer, but regular ordering this service will cost too much. And, of course, the situation becomes even more complicated when the physical life of the pipes expires. But there is good news: the renovation of pipelines is no longer accompanied by the tedious and costly destruction of walls, opening floors and earthworks in the house area. An alternative solution was a special material hardening under the influence of resins, which allows you to embed new pipes directly into the old pipeline. The use of this technology allows extending the service life of pipelines by at least 50 years, and in difficult cases, repairs are much cheaper than the traditional method of excavating and replacing pipes used in the reconstruction of a building. For many buildings where pipes are mounted on walls and floors, this is the only way to upgrade the pipeline.
Reconstruction of the installed pipelines of an industrial building. A photo: Terrat
Pipeline reconstruction at the University of Tartu Clinic did not interfere with the hospital
Between October 2017 and February 2018, Terrat reconstructed the storm sewers of the building of the Psychiatric Clinic of the University of Tartu Clinic at 31 Raya.
The cast-iron pipes of the internal storm sewer of the building of the 80s of the last century were worn out, which caused repeated water leaks into the premises. In the course of work, 27 storm sewage risers and main pipelines connecting the risers to the external sewer were reconstructed by a closed method. “It was about the building where the existing hospital is located and inpatient treatment is being carried out – the building was used around the clock, and the renovation was to interfere with the work of doctors as little as possible,” says Peps Pittsner, director of technical services at the University of Tartu Clinicum.
Since storm sewer pipelines are mainly located inside wall structures and under floors, the Clinic preferred a closed reconstruction method. In the announced gostender, the private method proposed by Terrat turned out to be more economical.
Peep Pittsner, Head of Technical Services, University of Tartu Clinic
A feature that should be taken into account when planning and conducting any construction work in our medical buildings is that we cannot move or suspend our activities at this time. The closed method of reconstruction proposed by Terrat allowed limiting to the minimal volumes of dismantling and restoration work, noise and dust, which are so disturbing for patients and staff during ordinary repairs, was much less.
“A feature that should be taken into account when planning and conducting any construction work in our medical buildings is that we cannot move or suspend our activities at this time. The closed reconstruction method proposed by Terrat made it possible to limit the minimal volumes of dismantling and restoration work, noise and dust, which the patients and staff are so worried about during normal repairs, was much less, ”says Pittsner.
He emphasized the flexibility, patience and ingenuity of the Terrat team during the course of their work: “The pipelines turned out to be“ children of their era ”and were completely out of line with the drawings. Over the decades of their existence, they have been patched and rebuilt several times. In the course of the work, new surprises were discovered, and miracles of deduction had to be shown in order to understand the intricacies of pipes. But in general, I can safely recommend CIPP technology for the reconstruction of pipelines in existing buildings both from the point of view of a gentle working process and from the point of view of the final result. The installation of the “stocking” inside all the bends of the existing pipeline was extremely successful.
Pipe repair in Old Tallinn between sewer wells. A photo: Terrat
Housing partnership: Terrat saves the nerves and money of residents
Residents of a 1980 apartment building built on Liivalaia Street were concerned about the leakage of a storm sewer on the roof – during heavy rains, the walls in the apartments got wet, water flowed from the sixth floor to the basement, and it was not possible to find the leakage site. “The flat roof, parapets with a height of 1.60 meters and the fact that cast-iron pipes were laid parallel to the ventilation shafts in the bathrooms complicated the problem of replacing pipes. Most often, ventilation shafts in bathrooms are built up. To replace the pipes, it would be necessary to break the walls in apartments located in the repair zone, ”Peeter Keari, chairman of the board of the apartment association Liivalaia 40, describes the situation.
The only option was the method proposed by Terrat. The Terrat team has already performed work in neighboring houses, having proved themselves well, and in the summer of 2018, specialists came to the house to inspect the pipes using a camera.
Peeter Keyari, CT Chair Liivalaia 40
With the help of compressed air, the “stocking” impregnated with resins was pushed from the basement pipe to the roof by as much as 20 meters. In one day the pipes became as good as new, the specialists completed the work without dismantling the walls and without entering the house.
“And they got down to business! It was necessary to choose a day without precipitation and make way for cars with equipment in the parking lot. Impregnated with resins, the “stocking” was pushed with compressed air through a pipe in the basement to the roof for as much as 20 meters. And in one day the pipes became as good as new, experts completed the work without dismantling the walls and, in fact, without even entering the house. The project cost 3000 euros, and we consider it a great investment, since we saved the nerves and money of the residents.
Timely reconstruction of pipelines prevents excessive repair costs
Pipes are damaged by corrosion and humidity, as well as chemicals and waste entering them. Therefore, horizontal pipes should be washed every 3–5 years, carried out their tele-inspection and, if necessary, renewed. Diagnosis of the riser by specialists takes about an hour. Horizontal pipes before examination are cleaned with a pressure washer. Reconstruction of the riser by a closed method takes an average of 1 day.
The technology of pipe reconstruction using soft materials has been used since the 70s of the last century and is constantly being improved. An elastic fiberglass fabric, the so-called “stocking”, is impregnated with resins and placed inside the old pipe with compressed air. The material impregnated with resins hardens under the influence of ambient temperature; to accelerate this process, the pipeline is heated with warm water or steam. After curing, a new, completely waterproof pipe forms inside the old pipe.
Established in 1992 on Estonian capital, a construction company specializing in environmental construction. He is engaged in the design and construction of water supply and sewage pipelines, their reconstruction using the trenchless method, the construction of hydraulic and environmental structures, parks and fountains. Terrat has developed and implemented an integrated quality, environmental, health and safety management system in the company that complies with the requirements of ISO 9001: 2008, ISO 14001: 2004 and OHSAS 18001: 2007, which has received the necessary recognition and approval from certification firms Det Norske Veritas and Bureau Veritas Certification.
Additional information and advice: project manager Elner Rannu; +372 518 2656, firstname.lastname@example.org