Abatement by Encasement: Safeguarding People while Saving MoneyTM

Ice Arenas – Rochester, MN

Case History

Property:

Ice Arenas

Location:

Rochester, MN

Challenge:

Two indoor ice arenas that are part of the Rochester Recreational Center have ceilings constructed using cementitious coated pressed wood fiber acoustical panels similar to a well-known product having the trade name “Tectum”. These panels, which sit on purlins and other steel structural members that support the roof above, offer excellent acoustical properties as their construction leaves significant interstitial space. These 1970 era rinks, with the years of dirt collected in this interstitial space, along with a few roof leaks that occurred along the way, and of course the continual source of humidity from the ice and ice-forming system, created a poor indoor air quality state, with unacceptably high counts of stachybotrys and other fungi. From the ice surface one could see the dark yellow and black staining throughout the surface of the panels. Also the structural members were showing their age under such conditions with visible corrosion throughout. The cost of remediation options involving removal and replacement was estimated to be in the millions of dollars, out of the question for this community to bear. A single coat system to seal off the surface of the panels was considered, but abandoned as it utilized a pesticide as it’s means for passing ASTM D3273/D3274, the test for mold resistance of a coating. The inclusion of a pesticide requires specific signage and posting of this fact, plus parental notification to all the school districts that use the facility, also applicators must have current pesticide applicator licenses. Moreover, the use of a pesticide is always accompanied by the potential risk of occupants having allergic reactions, as previous incidents with this particular pesticide (IPBC, iodine containing) have shown. Also this coating system is not designed for metal surfaces, necessitating the use of an entirely different system for the steelwork, making the project logistically more difficult and thus more expensive. For these reasons this alternative was not chosen.

Solution:

SAFE Encasement Systems was chosen for two of the many advantages that it offers, namely the ability to provide a mold-resistant surface without the use of a pesticide, and long-term corrosion resistance without necessitating sand-blasting (see ASTM salt spray and humidity cabinet data showing its appropriateness for use over metal surfaces). All panel surfaces were HEPA-vacuumed to remove loose contaminants, and all metal surfaces were scrubbed with a water solution of Chlor*Rid to remove corrosion-inducing soluble salts. All panel surfaces were sprayed with SE-110 surface stabilizing primer, while all metal surfaces were sprayed with the corrosion inhibited version of this primer, SE-110-CI. SE-120 Protective-Skin topcoat was then spray applied over all metal and panel surfaces. After the project got underway using the aforementioned method, it became obvious that inordinate amounts of encasement materials would be required to achieve a pinhole-free continuous coating over the panel surfaces. A decision was made to spray the panels first with an inexpensive elastomeric block filler followed by the SE-120 topcoat. This minimized the consumption of the more expensive encasement materials and resulted in a remediated facility (final air tests for the presence of mold were negative) for less than 25% of the cost of the removal and replacement option. This environmentally-friendly coating system was installed by Veit Environmental, Inc, of Rogers, MN.

Before

Before

After

After