The buildings were completed in 1972. The façades of the prefabricated apartment buildings are made of painted washed concrete The buildings include a total of 98 apartments housing a couple of hundred inhabitants.
The renovation of the housing association's sewage pipelines was discussed already in 2015, when structural problems were observed in the buildings’ plastic sewage pipelines during the renovation of the water pipes.
‘The light grey plastic pipes had deteriorated over the years. They had to be protected already during the pipe renovations’ (link to pipe renovation content when available), says Harri Saloranta, Chairperson of the Board of the housing association.
‘A couple of years later, we ordered a sewer condition survey from LTV Virta Oy in Tampere. At the same time, the possibility of repairing the pipes using the CIPP lining method was assessed. ‘
Ruptured and leaking pipes had already been detected in the buildings in the past, so their renovation was clearly necessary.
Housing Association As Oy Poppelikatu 11–13,
City of Lahti, Southern Finland
In-House CIPP Lining project in Finland City of Lahti requiring strong expertise
At the end of 2020, the plastic sewage pipelines of four apartment buildings in the centre of Lahti were lined over the course of about two months. The project and schedule were challenging, so having access to Picote’s skilled installers and efficient CIPP lining methods was essential.
Fast action following a tight schedule
CIPP lining (link to the CIPP lining page) was chosen as the method as it seemed like a functional and inexpensive repair method. In 2019, repair plans were drawn up and a tender was held. Picote Oy, which had extensive experience in various CIPP lining projects, was chosen as the CIPP lining contractor.
Since 2008, the Picote method has been deployed in a large number of CIPP lining contracts in over a thousand sewer renovation projects. Picote’s CIPP lining method also holds the product certificate EUFI29-20004643-C, issued by Eurofins Expert Services Oy.
The corona pandemic slightly delayed the decision-making process at Poppelikatu, but in the summer of 2020, the decision to embark on the CIPP lining project was made at an extraordinary general meeting of the housing association. Project supervision was ordered from LTV Virta Oy.
The actual CIPP lining began in October.
‘We wanted the work to be completed by Christmas, so the schedule ended up being rather tight. In the end, however, the project was completed a week ahead of schedule’, Saloranta points out.
‘The tight schedule meant that several vertical lines had to be fixed simultaneously. Residents were kept informed of the progress of the project at all times, so they could follow the work schedule.’
Most residents stayed in their apartments during the renovation, although the use of water had to be restricted during 1 to 2 weeks in each apartment. The showers, toilets and water points in the basement sauna facilities were of course available to all residents during that time.
Complicated pipe structures
The housing company’s sewage pipelines are composed of 110 mm diameter plastic pipes, which were insufficiently supported in some places.
‘In some parts, the pipes had no lower support other than pipe collars. Let’s remember that current practice advocates the use of supporting casts under pipes’, Saloranta points out.
‘Some hidden sewers, i.e., line reserves made in the past, were found during the renovation work, which had not been completed nor marked in the drawings. For this reason, some of the Y-branches of the pipes had to be re-lined.’'
According to Saloranta, the CIPP lining project was successful. ‘Competence is central to the quality and completion of repairs. Professionality is key, as it avoids situations where renovations have to be carried out continuously. The project was successful. The post-renovation cleanup was also handled in an exemplary manner.’
‘The price of the CIPP lining contract compared to other repair methods was also a positive surprise. The price of the renovation (CIPP lining) was only about one third of what would have been the cost of new pipes, less than one hundred euros per square meter,’ Saloranta estimates.
‘Also, Picote’s installers displayed a good attitude. Residents must be taken into account in such projects, where renovations are carried out in people's homes.’
CIPP lining of sewer pipes is a durable solution (CIPP lined pipes are durable)
Ilkka Pollari, the technical manager of the housing association and the managing director of Saksalan Huolto Oy, points out that the project schedule was really tight. The CIPP lining was carried out in the course of about two months.
‘In the tallest building, renovation of the elevator was scheduled to start at the turn of the year, right after the CIPP lining project was scheduled to end, and therefore the CIPP lining could not be delayed.’
‘The old-fashioned plastic sewer pipes that had in fact suffered a few pipe ruptures in 2019 also produced some challenges’ (link to repair services), Pollari recalls.
‘We had previously considered that CIPP pipe lining could be a good repair method. Along with the sewer condition survey, we also requested a report from LTV Virta Oy on whether the sewer pipes of the property could withstand renovation. The report stated that CIPP lining would be possible.’
‘Picote Oy, which we were not familiar with before, but which we had heard had solid experience in the CIPP lining industry, was chosen as the contractor. We saw that the company's personnel were highly professional. Picote took care of the job as they were supposed to,’ Pollari says.
Importance placed on project managers
Mikko Saarijärvi, who acted as site supervisor in the CIPP lining project, had previously worked as a designer and supervisor at LTV Virta Oy for a total of five years. He recently joined Picote Oy as a CIPP lining specialist.
‘There were several challenges in the Poppelikatu project. First of all, the property was relatively large’, says Saarijärvi.
‘Also, the housing association wanted to get the repairs done on a fairly tight schedule. As a result, many installers had to work on site simultaneously. We also knew that broken sewer pipes had already been found in different places.’
The work had to be done on schedule and well, so the role of project managers became very important.
‘At times, there were up to three project managers supervising the work at the same time. This made things easier, as did the fact that all the installers were skilled professionals.’
‘Often, you have to start thinking about the next stage of work already during the CIPP lining phase. This is why project managers must have both know-how and experience’, Saarijärvi points out.
