I RECENTLY FINISHED up the largest project on which I’ve ever bid and been accepted. It was a large (13,000-sq.-ft.) snow-melt system for a major player in the retail business.
This project was located in the Rocky Mountains of Colorado at the 9,000-ft. altitude level, where there are two seasons, construction and ski. The line between these two seasons is thin and is constantly changing.
The boiler room for the snow-melt system is located on the opposite end of the building where the snow-melt was schedule to be installed. The owners could have saved a substantial amount of money by moving the physical plant closer to the targeted area but, due to certain store standards, it was left in the area where it was originally slated to go, some 600 ft. away from the snow-melt area.
With an internal ceiling height of 20 ft., and a finished ceiling height of 14 ft., this left 6 ft. of vertical space in which to cram all the other necessary mechanical, electrical, communications, life safety and HVAC systems.
The subs agree
The coordination and allocation of vertical spaces was left up to the subcontractors. We held weekly progress meetings between the general contractor and the subcontractors, and we had one initial coordination meeting between the affected subs in the limited space.
The fire protection contractor was required to be the lowest, with all his piping located closest to the finished ceiling for obvious reasons. Next came the plumber, who said that as long as everyone maintained a flat profile that he would just “work around” everyone else’s systems.
Next came the electrician, who said that all his piping materials would stay at the level he had already established, and that he too would have to work around whatever happened in the field.
Then came the HVAC contractor who was required to stack his supply and return ductwork, which left the lowly hydronics contractor (us!) the last 8 in. of space in which to install 225-lb., 21-ft. long lengths of 4-in. schedule 40 grooved steel pipe. A challenging task for sure, but not impossible.
So, the vertical space was allocated, with the hydronic system being the highest, HVAC ductwork below it, and plumbing, electrical and fire protection coming in below that.
The building is approximately 1,200 ft. by 800 ft., and the concrete slab was poured beginning from the center, then starting on the outside and working around the building in a clockwise fashion. Unfortunately, the slab portion that we needed to have poured (so we could use our man-lifts to hoist the pipes) was one of the last sections to be poured, and our piping ran parallel to the longer dimension of the building.
Even more unfortunate, the fire protection and HVAC systems ran in the opposite direction to the hydronic piping, with their mains and rooftop units starting from the middle of the building. This meant that the fire protection and the HVAC contractors got a substantial jump on us on the installation of their mains and branches. They were waiting at the edge of the un-poured slab that we needed to get on first like a bunch of vultures, salivating over some curing carrion.
Unfortunately, due to summer vacation schedules and a very busy work summer in town, I had a limited work force on the jobsite, and all my manpower was tied up in the back of the building installing a snow-melt system for the loading dock when the front critical slab was poured. Consequently, all the other trades had their mains and branches installed before I had the chance to get my large, heavy, long pipes installed at the highest point, as we had previously discussed. I understand they had their job to do, and I had mine, but I honestly believe they could have been doing other things for the week when we were bound and gagged that would have allowed us to get into place in proper sequence.
Over the top
Coming in late in the construction schedule meant that we had to work over the top of all their equipment. This added the challenge to our job of having to parallel-park 21-ft. long pieces of 225-lb. steel pipes over the top and through existing steel pipes and ductwork.
The next time this type of challenge presents itself I will be paying much closer attention to timing details, and I will make sure the other trades understand the critical need for me to be installed first, not just the highest.
Even though I found myself boxed into a tight, time-critical corner, we were able to get the piping installed in a timely manner and stay ahead of the project time line. It did require some rather precarious pipe positioning using multiple man/material lifts to get the job done, but nonetheless we got it done.
Getting work done in a manner that doesn’t hold up the other trades is important, as we found out, and we had to go out of our way to make sure we didn’t hold up the other trades. I guess that’s why they call it trade cooperation.
Next month, I will show you some of the tools we used to expedite the installation and discuss their applications.
Until then, Happy Scheduled Hydronicing!!
Mark Eatherton is a Denver-based hydronics contractor. He can be reached via e-mail at [email protected] or by phone at 303/778-7772.