GLY’s Most Intricate Demolition?

How do you safely demolish a three-story building at a hospital’s core while keeping its basement’s critical systems functioning without disruption?

Well, surgically—because every campus system and access point is essential. We brought the same care for campus occupants that Overlake provides to each patient.

Functional Systems

Dozens of functional systems ran to or through the building, requiring careful reconfiguring or capping before demolition—with no room for error. Power, communications, med gases, halon, fire sprinkler, oxygen, pneumatic tube, steam, and so on. Many serve the occupied basement and needed to stay active for patients campuswide. We had to learn every system, and the early-60s blueprints were only a start given the countless building upgrades since.

Due diligence takes time. Over four months we dug into every corner, opening walls and ceilings to document the precise locations of every system component. There were 300 low-voltage wires alone. We spent an additional six weeks reconfiguring, capping, and testing, coordinating very closely with the Overlake Facilities team.

The largest piece of this puzzle? Relocating the PBX [private branch exchange], the core system node for paging, security, lockdown, alarm panels, duress buttons, nurse call, and more. Before starting demolition, we built a new PBX in a new location and made sure it was up and running properly.

With functional systems protected, it was demo time!

Main Demo

Two non-negotiables during demolition included:

1. Keeping the basement and adjacent areas [e.g. glass atrium cafe and driveways] operational and safe. This building was within inches of high-traffic areas. We topped the nearest driveway with a temporary structural steel frame and plywood sheeting to protect users 24/7.
2. Waterproofing the occupied space below the building. Water posed a serious threat to the data center and electrical and chiller rooms. To mitigate this risk, we protected the existing waterproofing, walked the site three times daily, and patched as needed.

The team carefully broke the structure down with a demolition processor—a safer, less-disruptive, and more controlled method than large hydraulic jackhammers often used on big buildings to break apart concrete. The tracked vehicle uses a claw to grip and pull chunks of the building and break them into the small pieces for recycling. For abundance of caution, downstairs remained off limits to people when the processor was on the slab above.

Moving Seamlessly into Construction

Instead of waiting for demolition to finish, new construction overlapped to reduce the overall project duration and protect occupied areas.

Basement Enclosure

With no time to waste, we immediately got to work on a permanent roof enclosure for the existing basement. Working north to south behind the demolition processor, the team converted the original ground-level floor into a full enclosure, augmenting the structure, eliminating openings and penetrations [for the old stairs and functional systems], and waterproofing.

Driveway Structure

The planned driveway above the basement called for a much stronger base. Strong existing footings, per testing, allowed us to pour a 14 – 16“ concrete slab over the basement “roof,” making the area ready for cars and trucks of considerable size to pass through.

Careage Connector

Soon much of Overlake’s campus will be directly accessible via a weather-protected, welcoming, glass-enclosed walkway traversing the campus core—a "front door" with entries for each building. This will save people time getting from point A to point B during their stay, shift, or visit.

Rebuilding the Existing Driveways

Working in close quarters and around truck load weight limits required a bit a traffic rerouting—for everyone. Until vehicles can fly, we still need room to get material safely in and out of the jobsite. Going temporarily from a two- to one-way driveway through the campus did the trick. The change made room for a lane dedicated to truck deliveries and debris removal for several months.

Now we're rebuilding much of the new driveway system including curbs, gutters, walkways, and landscaping. It'll be back to two ways in October, looking like new, but we know change—even if temporary—can be disruptive. Many thanks to Overlake's staff and visitors for their patience!

Helping Overlake and Generations of Patients

In the construction field we get to help clients achieve their visions. Healthcare work is particularly fulfilling because each project truly impacts people's lives.

We're immensely proud to partner with Overlake, and benefit thousands of patients, families, and staff!