Wednesday was a big day. First thing in the morning, we unloaded the liner and unrolled it. A 50 foot by 40 foot liner like this weighs over 600 lbs! Once the liner was unrolled, we had some last minute prep left. The Urban Escapes crew rented a 14″ concrete saw and cut some shallow channels in the floor of the vault. When the vault was installed it was level, but on Wednesday the level bubble hugged one side of its marks. Water pooled on one side of the vault so extra drainage was necessary.
The first step was to get the liner positioned in the pond. The four Urban Escapes workers were able to stand the roll up on its side against the pond wall and we slowly unrolled it along that wall. Once it was off the cardboard roll, we used the trackhoe to to pull it up over the edge of the vault and started to unfold it. To anchor one part of the liner, we moved the old waterfall rock into place on the east side of the pond. The rock now cantilevers out over the pond about 18 inches and gives me mild vertigo standing on the edge looking down at the bottom. Cool.
After lunch two of the Urban Escapes crew built a beautiful wall using some of our sandstone rocks. The other two workers and myself attached the three bottom drains to the liner in the bottom of the pond. Once the bottom drains were installed, we used batten bars to attach the liner to the front of the vault. This was a little tricky because the front of the vault has a 45 degree slope in front of it. We ended up standing in the vault on ladders and bending over the front to screw in the stainless steel screws. The crew applied a liberal bead of of 100% silicone caulk between the liner and the vault wall.
We finished up the day by installing the bulkheads. We used an approach similar to bottom drain installation to make sure everything was water tight. Unfortunately, my fear that the holes in the vault wall were too small was warranted. While the bulkheads fit fine, the holes didn’t leave enough room to for two hands to tighten the bulkhead nuts as much as I would like. I’ll probably apply an extra bead of caulk around the pond side of the bulkheads to help prevent leaks. Overall I am happy with the progress though, and I wish I had a little more vacation to see this through to the end of the week.
Tomorrow the Urban Escapes crew will started placing our sandstone boulders around the pond. We’re so close!