Cover Board Installation for Single-Ply Roofing: What Homeowners Should Know

Single-ply roofing systems are a popular choice for both commercial and low-slope residential roofs in Gainesville and the surrounding areas. But what often gets overlooked is a critical part of the system: the cover board. At L&L Roofing & Construction, we believe in doing the job right—every time. That means helping you understand not just what we’re installing, but why.

Here’s what you need to know about cover boards and why they matter for your roof’s long-term performance.

What Is a Cover Board?

A cover board is a thin, rigid layer placed between the roof insulation and the single-ply membrane (like TPO or PVC). It plays a crucial role in:

• Protecting insulation from damage during installation

• Providing a stable surface for the membrane

• Improving fire resistance

• Boosting hail and impact resistance

• Minimizing foot traffic damage

Think of it as the insurance policy between your insulation and the weatherproofing membrane.

Why Do We Use Cover Boards in Georgia?

In Georgia’s variable climate—heat, humidity, and occasional hailstorms—roofs take a beating. A cover board helps absorb that stress before it reaches the insulation layer. Especially with flexible membranes like TPO and PVC, having a stable base keeps the roofing material from tearing or failing prematurely.

Types of Cover Boards We Trust

Not all boards are created equal. Here are a few types we commonly install:

• Glass-mat gypsum boards (like DensDeck®): Moisture-resistant, mold-resistant, and fire-rated.

• Polyisocyanurate-faced boards: Combine R-value with added protection.

• High-density wood fiber boards: Great for mechanical strength and insulation compatibility.

The right choice depends on your roof’s slope, insulation, and exposure. That’s where our expertise comes in.

Common Roof Decks We Encounter

Whether your home or business has a plywood, metal, or concrete roof deck, we’ve seen it all. We always inspect and prep the deck before installing insulation and the cover board. Here’s how we approach each:

• Wood decks: Fasten boards securely, use compatible adhesives or fasteners.

• Metal decks: Ensure secure insulation and smooth transitions; no abrupt ridges.

• Concrete decks: Verify dryness and surface condition before attachment.

What Happens Without a Cover Board?

Skipping a cover board might save a few dollars up front—but can lead to:

• Crushed or warped insulation

• Leaks from punctures or membrane damage

• Shorter roof life

• More costly repairs down the line

We’ve replaced too many failed roofs where this shortcut was taken. At L&L Roofing, we don’t cut corners.

FAQs

How thick is a typical cover board?

Most range from 1/4" to 1/2" thick, depending on the material and roofing system.

Is a cover board required by code?

It depends on your jurisdiction and roofing system. That said, many manufacturers require them for warranty coverage.

Will a cover board affect insulation value?

Slightly, but in most cases it adds less than R-1. The trade-off in durability is well worth it.

Can cover boards help with hail resistance?

Yes. Certain boards (especially high-density gypsum) improve impact ratings and help protect the membrane and insulation during hailstorms.

Honest Roofing Starts With Strong Layers

At L&L Roofing & Construction, we don’t believe in shortcuts—only strong, long-lasting roofs built with faith, honesty, and craftsmanship. Whether we’re installing a TPO roof on a church in Cumming or repairing a flat roof on a business in Gainesville, we install every cover board with purpose.

Got questions about your flat or low-slope roof? Call us at (770) 874-0372 and talk directly with Luke Heaps or one of our experienced team members. We’re here to do the right thing—because it’s the right thing.