Metal buildings were introduced to the Bahamas over 75 years ago. Some of these buildings are still standing and being used, and many are squeaking by with leaks and holes that need to be repaired. Our proximity to the ocean and tropical weather tends to age steel buildings faster than we would expect.
Depending on the age and condition of the building, there are essentially three ways to solve your leaking metal roof problems:
Repair – the least costly option, this usually involves patching with scrap pieces of roof sheeting or coating with a roof membrane. This will buy you some time, but is essentially (and literally) just putting a patch over the problem.
Retrofit – If your existing R-panel is in need of replacement or repair, TMC offers two low-cost retrofit solutions to renew the existing roof. These reroofing options allow the existing roof to remain in place, which saves on labor costs while minimizing the chance for water entry into the building during the roofing process and providing for a safer working environment. Existing roof top equipment, vents or light transmitting panels can be accommodated by either system.
Renovate – this is the most costly option. Typically, if a roof has had many and major leaks over the years, the substructure may need replacing. TMC can remove the existing roof and the secondary framing, and replace with new, galvanized secondary framing. At the same time we clean and reinforce the existing frame columns, and can repaint if required. New high R-value insulation systems are usually installed at this point as well.
Our recommended solution is to Retrofit. This option usually works in 3 out of 4 cases – the 4th case requiring a full Renovation.
For a Retrofit over R Panels, there are typically two solutions:
Solution 1: A New Standing Seam Roof
The first option for retrofitting over an existing R panel roof is one of our trapezoidal standing seam roof systems. The 24-inch wide Double-Lok roof panel is a mechanically field-seamed system. It requires a minimum slope of ¼:12. Double-Lok is UL-90 rated and FM Global rated. When choosing the Double-Lok option, high clips are used to provide clearance between the Double-Lok
panel and the major ribs of the existing R panel.
There are two options to increase the energy efficiency when using the Double-Lok panel over an existing R panel. The first is adding two-inch unfaced fiberglass insulation between the existing R panel and the new Double-Lok panel. The second is to vent the cavity between the old and new roofs by adding a vent strip at the eave to allow air intake and a vented ridge to provide for air exhaust. This method works well with roof slopes of 3:12 or greater.
Solution 2: The Retro-R Panel
The second option is using TMC’s Retro-R panel over the existing R panel. The Retro-R panel has rib spacing 12″ on center with a rib height of 1-1/16″. The minimum slope for the Retro-R panel is ½:12. The existing lap screws must be removed from the R panel roof before the Retro-R panels are installed. The screws that attach the existing R panels to the purlins do not have to be removed. The Retro-R panels are attached with special shoulder screws that fasten through the existing R panel major ribs and into the existing purlins. Once the Retro-R panels are installed, new lap screws are installed through the Retro-R ribs and into the existing R panel side laps.
The downside to the cheaper Retro-R solution, is that insulation cannot be installed.
Whichever method you choose, TMC Engineering Ltd. can provide a free estimate to get the process started. Call or email us for more details or to schedule an on-site appointment for a free analysis!