SLIDESHOW

North Parking Office Upgrade at Atlanta’s International Airport

Sentry Roof recently completed a re-roofing project for one of the outbuildings at the Hartsfield-Jackson Atlanta International Airport — we did this project concurrent with the major work we’re doing on Concourse E. The building is directly adjacent to the elevated North Parking Deck (no extra security clearance needed for this location) and a new roof was part of the architectural drawings.

The old roofing system was failing for several reasons, all of which we were able to correct using a variety of techniques.

Swipe through the slides to see what we did (turn mobile device sideways for best viewing):

1.
Here you can see that the OSB board (oriented strand board) did not support the uplift requirements. Many areas were significantly degraded and deteriorated from old roof leaks.
2.
What we found underneath the board was not a standard metal roof deck and not the type of deck we can attach insulation to effectively. There was no insulation but the roof may be have been insulated from the interior.
3.
The flags are the perimeter warning line system. They visually mark the line that’s six feet back from roof edge.
4.
The black material you see here is a base layer, an underlayment, for the old roof membrane. Here our technicians are in the process of removing it.
5.
Now all of the underlayment and OSB has been removed and you can see the structure of the metal roof deck.
6.
Now that’s a deck we can attach insulation to! The structural sheathing we installed over the top of the metal is new ⅝ tongue and groove plywood.
7.
Here our crew is finishing up with the plywood. We had to deal with a lot of popup thunderstorms during this project but it’s not a problem if plywood gets wet. We allow the moisture to dissipate before we apply the roofing materials.
8.
As you can see, we used a lot of insulation on this project. The original roof wasn’t sloped properly and it held a lot of water. The new design corrected the problem with layered insulation board that tapered ¼ inch per foot to create a slope for proper drainage.
9.
The insulation is thicker at the middle of the roof and thinner near the roof edge. There are different ways to accomplish creating the slope — this was the most effective way for this roof system.
10.
This is a peak of the roof. We used different numbers of layers in different areas of the hip-style roof — the peak has four layers. The circles you see are metal disk fasteners (like washers) called insulation plates. They hold the insulation to the substrate and come in many different sizes and types.
11.
Just above the bottom left corner of the photo you can see where the corner angles come together. They’re mitered like a picture frame at 45% angles to make sure all surfaces are equal. This photo shows the initial temporary securement prior to finishing the attachment pattern.
12.
We had another pop-up thunderstorm so we had to quickly protect the insulation. Since this project was small, we were able to use a single tarp raised at the wall to protect the entire roof.
13.
Now comes the membrane — this is 80 mil TPO (the heaviest TPO product on the market right now) from Firestone that was used to achieve a 30-year roof warranty. You can see we needed to install plywood against the grooved surface of the concrete to provide an adequate surface to adhere the roofing flashing.
14.
What’s in that bucket? Bonding adhesive. It’s installed like a contact cement — coat both surfaces, allow them to tack, then mate them together. We used the same Firestone bonding adhesive for the insulation and roof membrane, which is part of the warranty.
15.
This is a unique penetration. We needed to make a watertight seal around this series of conduits that hold electrical lines, phone lines and internet cables.The pipes came up from the back of the roof around the parking lot wall.
16.
Here it is completed.
17.
Here’s another situation that required special attention — there’s a lot of high-voltage material going through those pipes. We field-formed a flashing to make an extension and sealed the end with a stainless steel clamp and a specialized sealer material.
18.
If you look closely you can see where we fused the sheets of membrane together. Not only did we apply adhesive to 100% of the insulation surface but we also thermally fused (heat welded) the laps (edges) together to bond them molecularly. The material is just as strong at the seam as it is in the middle of the sheet.
19.
These are typical plumbing pipes coming up through the roof — and this is typical plumbing flashing. We used preformed flashing boots and heat welded them to the roof surface and then sealed them along the top. This water-tight connection also accommodates any movement in the pipes.
20.
As with the flashing, a flexible expansion joint in the roofing material accommodates movement between the new roof and the existing parking lot wall. This new roof needs to stay put together and not open up or pull apart anywhere for 30 years of stress, abuse and weather — and it will.