Once in a while, every one of us in Tecta is fortunate to have an opportunity to be part of a project that turns out to be a great deal of fun - more than anything the challenge is the fun part.

The project we call, The Cliffs, is owned by Marfield Belgarde & Yaffe (MBY) Enterprises in Minneapolis, Minnesota. The Cliffs is an upscale apartment complex with many of the tenants being professional athletes. The buildings were originally built in two phases and are only 10 to 15 years old.

The Cliffs consist of 6 buildings, each with a unique identifying architectural feature of round half dome roofs over the main living area of the top floor units. These domes hang over the private balcony decks of each unit below. There are 26 dome roofs on each building for a total of
156 dome roofs throughout the entire complex.

The Problem
The relationship between The Cliffs and Central Roofing Company (CRC) began 3 years ago when CRC started servicing and maintaining their roofing systems. However, time and time again, during certain times of the winter months, tenants would experience leaking from the dome
roofs to built-up roofing connection areas, even though all the built-up areas appeared to be in satisfactory condition. CRC started replacing base flashing at the bases of many of the domes. MBY's costs continued to increase each year for service and maintenance of these roofs. Water entry into the building continued to pop up in areas where maintenance had been completed that appeared to be water tight. When we water tested areas there would be no water entry. We began to speculate that the domes may not have been originally insulated properly, and that there could be a condensation problem.

Working closely with MBY, CRC hired an outside roofing consultant, Terry Thone from Roof Spec, Inc., and decided to investigate the problem. Deciding to open up the domes was a big decision. Once the dome areas were opened up and the connections to the flat roof areas were exposed,
our speculations were confirmed. The problem was diagnosed as being condensation and an insulation problem at the dome roofs. Along with the condensation leaks, were the beginnings of a mold problem too.

Best Practices
The tough part was not only finding a good solution, but being diligent to repair only what was needed while meeting a tight budget. Initially, we specified a complete removal of all dome roofing and decking, followed by fully insulating the joist cavities. With 156 domes to open up, every little change made significant budget differences.

Our pricing ranged from 1 to over 2 million dollars depending on what MBY and Roof Spec, Inc. decided would be the best solution. MBY requested a proposal to open up and apply urethane foam at the connection cavities in order to close off all sources of air infiltration into the cavities. Before being awarded the project, we tried this solution on two domes as a trial and waited through one winter season. The test roofs performed well.

The budget meetings with Chris Johnson, a partner at MBY, were long, tedious and little fun. We explored different roofing systems and budget scenarios. They wanted the best solution without jeopardizing quality at a reasonable cost. We ended up insulating key areas, checking other areas and reroofing all 156 domes with a 60-Mil fully adhered EPDM. The dome joists were spaced at 12" on center and filled solid with batt insulation, except at the base. The warm to cold transition at the deck overhangs and base connection was determined to be the air infiltration problem. Because of the infiltration and the fact that these critical areas were not insulated properly, the dew point temperature was achieved with the joist space resulting in condensation of moisture vapor within the joist space. Water would enter the building appearing to be a roof leak.

Safety was key to setting up for the beginning stages of this project. We set up extensive safety requirements and consulted with our safety expert, Ryan Romer. We were already aware of the dangers on these buildings since a competitor's roofer fell during the original construction and was killed. The buildings were built tightly on the sight and the only access for the overhanging dome roofs was from the roof.

The Solution

First, we needed to tear off all the shingles from the 156 domes. Second, we scudded back the built up roof (BUR) areas around the domes in order to cut open the decking and insulate tightly at the connection. Next, we cut out decking at the base tie in areas and the end walls, then finished with solidly spray foam insulating the joist cavities. New decking was installed as required, and we overlaid the entire dome roofs with a layer of 1/4" Densdeck board to achieve a good, bondable roof surface. We then had to again tie-in the BUR and be careful not to damage the existing BUR that already had many patches and repairs. Finally, we applied the new 60-Mil fully adhered roofing system and all new sheet metal flashing.

The Cliffs project is another great example of dedication and teamwork of a Tecta America company.