The procedure is inherently safe and non-disruptive, and is routinely performed in occupied buildings while warehouse operations continue undisturbed.
1. Make every lift point a steel telescope
Our prep phase focuses on either converting or replacing the existing columns into telescopes. We do this by either wrapping the with a 2-piece sleeve that is field assembled, or we remove and insert a new smaller tube inside of a larger tube.
2. Account for the perimeter
If there are columns at the perimeter, we place a new telescoping column in front of them. If there are not, we install new beams to support the wall bearing steel, with new telescoping columns underneath them. These are permanent steel members that remain after the raise.
3. Temporarily Brace
Typical erection cabling & bracing is added in addition to our columns being tied back to the footings. This helps protect the structure from any transient lateral forces during the short duration from separated to fully re-supported
3. Install our hydraulics and hardware
With the building prepped and ready, we install our lifting equipment. This equipment utilizes a double pin, double cylinder pumping system with proprietary hardware at each point, able to jack the entire roof up 1' at a time.
4. Separate the roof
The edges are cut and pulled back about 1'. Temporary flaps used to reseal later are typically installed. All vertical supply lines for utilities are separated or cut, and can be temped with flexible lines with slack. All steel wall ties are cut, and the building is thoroughly inspected to ensure it is free to go up.
5. Raise the Roof!
An enlarged crew, typically featuring 1 man for every 6 to 10 columns, comes to site to operate the hydraulics and lift the entire roof at one time. generally a roof can be lifted about one foot per hour, so raising typically takes 1-3 days.
6. Structural Re-support
Since it's all ISE ironworkers raising the roof, they can begin the structural re-support the same day the roof is done being raised. This involves permanently securing the inner part of the telescopes to the outer part (welding or bolting), splicing in perimeter column extensions, installing new cross bracing, and removing the hydraulics and hardware.
7. Fast-Panel Enclosure
If Fast Panels are included, they arrive in typically 12-20 foot sections on-site the day we raise. Once the roof is up and the wall has been properly prepped, these panels are set onto the wall utilizing a crane. A crew from the inside carries out final attachment, and the roofer follows behind to flash in the top and any high-low scenarios, making it water tight.
ISE also offers complete structural and miscellaneous steel work. Items like new HVAC supports, mezzanine steel, stairs/railings, roof access ladders, overhead door frames, lintels, bollards and even column removal or relocation can be included in our scope of work as requested.