Roof Recover and Overlay in Davenport, IA

Somebody from maintenance has already pulled a core and set the wet insulation on the loading dock. Now the question is whether the building can skip a tear-off.

Sometimes it can. A recover puts a new membrane over the existing roof, which saves disposal, shortens the schedule and keeps less noise and debris over the people working below. In Davenport, IA it only works when the roof underneath is dry, flat enough, and allowed by code. We check all three before we talk price.

A recover is a yes or no decision, and the answer comes from the existing roof, not from the budget.

1. Moisture. The insulation and deck must be dry or close to it. A new membrane over wet insulation traps the water and shortens the life of both layers.
2. Code. Davenport has adopted the 2021 International Existing Building Code with local amendments, and the number of roof layers and the added weight are among the things the building department reviews.
3. Structure. The deck and framing must carry the added dead load, plus snow. Snow in the Quad Cities adds up past 36 inches in a normal year, so winter loading is part of the math.

If any gate fails, we say so, and we price a tear-off instead.

Guessing does not work here. A roof can look sound from the hatch and be soaked at the middle of the bay.

We start with an infrared moisture survey on a clear evening, when the roof gives back the day's heat unevenly over wet areas. Then we mark and cut cores at the cold spots and at a few control spots that look dry. Each core gets a photo and a note on layers, fasteners and condition. The map goes in your report, so you can see where the wet areas are and how much roof they cover.

Small wet areas can be cut out and replaced during the recover. Large ones mean the recover is off the table.

What goes on top depends on what is underneath.

Over an old built-up or modified bitumen roof, we often install a layer of cover board first. That gives the new membrane a smooth, firm surface and protects it from the old roof's gravel or blisters. Over an old single-ply, the details change, since some membranes do not get along with the old one.

Common choices are TPO and EPDM, either mechanically fastened or fully adhered. Fastener patterns follow the wind uplift requirements for the building, and in a region where an 86 mph gust hit Davenport Municipal Airport in the August 2020 derecho, we confirm them against the code before we price the job.

A new membrane sits higher than the old one. That sounds small. It is not.

Drains have to be re-set so water actually reaches them. Curbs around rooftop units may need to be raised so the flashing height still meets the standard. Edge metal and coping often have to be replaced because the new roof pushes the old metal out of position. We walk every drain and curb with you and write down the ones that need work before the proposal goes out.

Ponding is the one thing a recover does not cure. A bay that already holds ponding water calls for tapered insulation, added drains or a tear-off.

The best thing about a recover is how it fits into a working building. With no tear-off, there is less debris and no open deck. Shifts in the plant below can keep running, and an office or clinic sees less disruption.

We still agree on access first. Who badges us in. Where the lift sets up. Which rooftop units stay on, and which can be shut down for a short window when we flash around them. The crew finishes each section the same day so the roof stays closed to the weather. The Eastern Iowa Industrial Center is mostly large low-slope manufacturing and warehouse buildings, and a recover on a warehouse roof like those can often go quicker than a tear-off, but the survey comes first.

Weather still matters. Adhesives and seam welding have temperature limits, and we plan around cold mornings and wet days instead of forcing the work. If a front is coming, the crew closes the section and waits.

A recover buys time. It is not a permanent fix, and it is usually the last layer the roof can take. We tell you that up front so the next decision is already on your capital calendar. When the recover reaches the end of its life, the building will need a full tear-off, and the plan for that should start years before the day it is needed. An annual roof inspection keeps the file up to date.

It also helps to ask what the recover will hide. A new membrane covers old patches, old repairs and old leak history. We photograph the existing roof before we cover it and keep those photos with your records, so the next contractor, or the next facilities manager, knows exactly what is under the surface and where the roof was wet in the past.

A recover estimate also needs a clear limit on what the new layer can solve. We map every existing repair, note soft areas and confirm that the old assembly is dry enough to cover. At the perimeter, the new membrane has to terminate without trapping water behind the edge metal. Those checks are where a low initial bid can change: saturated insulation, weak attachment or a detail that cannot be raised may call for selective removal or a full tear-off instead.