Birdair had conducted a regular inspection of the Metrodome roof in April 2010. Its report to the Metropolitan Sports Facilities Commission stated that "the outer membrane is in good condition and still holding up well", and rated the inner liner's condition as "fair to poor". The inspectors also noted that the inner liner of the roof was dirty (mostly due to emissions from automotive events) and had some holes in it, advising that the holes be monitored to avoid large tears from enlarging. Also, Birdair noted some minor areas on the outer membrane that needed repairing, which was done by the time of the Commission's July regular meeting. Overall, Birdair noted the membrane was weathering as anticipated and had exceeded its service life of 20 years; it recommended planning for replacement of the roof fabric and noted that planning and implementation would take an additional five years and cost $12–15 million. In forming their own conclusion, the Metropolitan Sports Facilities Commission staff decided that the outer membrane was in very good shape and that the roof continued to have serviceable life, and planned to schedule another testing in four years; the Commission made no recommendations.