FAQ: What Kind of Decking Is Required for Flat Roofing Systems?

When it comes to flat commercial roofs, the deck beneath your roofing membrane matters just as much as the material on top.

At The Roof Champion of Columbus, we regularly work with:

• Steel decking (corrugated metal)

• Poured concrete decks

• Wood sheathing (plywood or OSB)

• Gypsum-based panels

Here’s what really matters:
The deck must be structurally sound, dry, and code-compliant. If it isn’t, your new roof is at risk before it’s even installed.

Our Process

If we’re unsure about your existing deck's condition, here’s how we figure it out:

• Adhesion testing: We verify that adhesives will actually bond to the deck surface.

• Pullout testing: We confirm fasteners can grip without tearing out—especially important with older wood or lightweight concrete.

• Structural check: We look for deflection, water damage, or corrosion that could weaken the roof's foundation.

• Reinforcement or repairs: If we find compromised areas, we fix them or beef them up before roofing begins.

We’re not guessing. We’re protecting your investment.

Real-World Example

One of our recent commercial clients in Powell had a flat roof over a wood deck with years of moisture damage from ponding water. During our inspection, fasteners were pulling out with just hand pressure.

We reinforced the deck with additional sheathing, documented everything for their insurance adjuster, and installed a TPO system with full adhesion. They now have a watertight roof—and peace of mind.

FAQ

What if my deck is concrete?

Concrete decks are solid options for flat roofing. We’ll test for surface pH and cleanliness to ensure good bonding if adhesives are used. If there are cracks, we’ll seal or repair them.

Can a roof be installed over a damaged deck?

It shouldn’t. Code requires the substrate be sound. Installing over compromised decking almost always voids manufacturer warranties and leads to premature failure.

Do I need to replace the whole deck if it’s partially damaged?

Not always. We can reinforce localized areas with overlays, sistering, or sealants—whatever’s safest and most effective for your roof system.

At The Roof Champion of Columbus, we believe your roof is only as good as what it sits on. And we make sure both are solid.

Give us a call at (614) 639-3422 or visit www.roofchampcolumbus.com to schedule a free flat roof inspection for your commercial building.