Roof replacement is one of the most expensive capi-tal-improvement projects that buildings face. What should co-op and condo boards know going in?Invariably, roof replace-ments are costly, especially when you’re doing a full replacement and ripping out everything down to your deck. But when you do that, you can get a warranty called an NDL, which means No Dollar Limit. In the event of a leak, the manufacturer will repair any defects and cover the cost.What kinds of problems can crop up?At one building we ran into trouble because the roof replacement didn’t meet the height required by the manufacturer. There’s a new code requiring that roofs be built so that there are three or four inches of spacing between the roof and the through-wall flashing. That’s a sheet of copper that allows water that gets inside the parapet wall to drip out onto the roof and make its way to the drain.And what was the proposed fix?The engineer told us that a change order was needed. Those are two words you dread when you’re deal-ing with these types of big projects.Because it means more dollars?Yes, and sometimes it’s a lot. In this particular case, the engineer recommended removing the through-wall flashing and reinstalling it to meet the height require-ments, which would have cost well over $35,000.Yikes.It was a real shock. We asked the roofing manu-facturer to meet us on site with our engineer, as well as the engineer from when the flashing was first installed, hoping to find another solution. The manufacturer came up with a compromise and allowed us to install a liquid mem-brane between the new roof and the through-wall flashing, which would only cost $5,000. He also gave us a full no-exception warranty.Is this a common thing that you would get the manufacturer to come out to the building?No. They always come to do a final inspection to confirm the job has been done to their specifications before issuing their war-ranty, but it’s not common to ask them to come out during the course of a job, since it’s usually because you’re trying to find a way around something.What’s the takeaway for other boards?Always think outside the box.