Underneath view of large warehouse roofing system

From an investment standpoint, a warehouse roofing system is an invaluable asset. It protects the raw materials, manufactured goods, and other critical components that facilitate your daily business operations.

Did you know? Roughly 30% of a building’s structure (the roofing system) protects 100% of the people and assets inside of it.

Of course, any newly-installed warehouse roofing system should be watertight. It should also lower operating costs, reduce maintenance, increase energy efficiency, and improve appearance.

While modern roofing systems have long lifespans, routine maintenance is vital to their overall performance. Something as simple as a loose fastener or clogged drain can cause major problems—and even lead to premature system failure if left unaddressed.

When it comes to warehouse roofing, plenty of suitable options are available. But determining which one is best depends on a variety of external factors such as budget, climate, state and local building codes, roof construction, warranty requirements, building usage, etc.

In this post, we take an in-depth look at five of the most popular types of warehouse roofing.

Have a warehouse roof in need of attention? Click here to find an American WeatherStar Approved Contractor in your area.

5 Common Types of Warehouse Roofing

1. Modified Bitumen

Modified bitumen (aka mod bit) is a reinforced asphalt membrane blended with plastic or rubber polymers for added malleability. It is made into rolls with a smooth or granulated finish, with the latter offering superior durability and UV resistance.

Mod bit roofing membranes are highly durable—typically lasting up to 20 years or more. They also possess exceptional impact and tear resistance, making them ideal for roofs with heavy foot traffic or at greater risk of inclement weather conditions.

A mod bit roof’s primary drawback is cost, which is generally more than alternative warehouse roofing materials. Also, the installation time frame for these systems is comparatively longer than some other types of roofing.

2. Built-Up Roofs

Built-up roofs (aka BUR) have been around for a very long time—since the mid-1800s. While still used today, they are not nearly as common as they once were due to their somewhat unsafe and inefficient installation practices.

Built-up roofs comprise multiple layers of asphalt and ply sheets (or felts). The topmost layer consists of either a reflective aluminum coating (smooth BUR), a mineral cap sheet, or a layer of pea gravel (gravel BUR).

Built-up roofs are incredibly durable and long-lasting. It’s not uncommon for these systems to last up to 50 years or longer. They also have exceptional UV resistance and are suitable for nearly any climate.

The main disadvantages of built-up roofs are their high costs and lengthy installation processes. Also, as an asphalt-based system, BUR lacks flexibility which can put a lot of undue stress on roof surfaces.

3. Single-Ply (TPO, PVC, EPDM)

Single-ply roofing systems consist of a single layer (hence the name single-ply). These membranes come in rolls of various sizes and thicknesses. They can be fully adhered (with bonding adhesives) or mechanically attached (with plates and fasteners) to roof surfaces.

There are three main types of single-ply:

  • TPO (Thermoplastic Polyolefin) comprises layers of synthetic rubber and reinforcing scrim. It is a relatively newer roofing technology with a lifespan ranging from 10–25 years.
  • PVC (Polyvinyl Chloride) is a synthetic plastic polymer with a life expectancy of 15–30 years. It looks almost identical to TPO—so much so that it can be difficult to tell them apart.
  • EPDM (Ethylene Propylene Diene Terpolymer) is a synthetic rubber material lasting up to 40 years. It is often referred to as "the original" single-ply roofing membrane.

While notable differences exist, TPO, PVC, and EPDM are generally best known for being cost-effective, lightweight, and easy to install.

The bright-white surfaces of TPO and PVC offer excellent thermal reflectivity and UV stability, significantly reducing cooling costs for buildings in warmer, sunnier climates. Conversely, black EPDM membranes retain more of the sun’s heat, drastically reducing heating costs in colder climates.

The main drawback of single-ply roofing is its lack of durability. As a single-layer membrane, it is far more susceptible to sudden damage. Also, these systems produce a lot of seams, which can be vulnerable to leaks if not properly installed or maintained.

Additionally, single-ply roofs generally have a shorter life expectancy than the other types of warehouse roofing mentioned here.

4. Metal

For warehouse roofs, metal is among the most durable and longest-lasting materials (lasting anywhere from 40–80 years).

There are various types of metal roofing:

  • Steel is the most common and has the most reasonable price point. It is typically coated with aluminum or zinc to improve its reflectivity and corrosion resistance.
  • Aluminum metal roofing is durable, lightweight, and easy to work with, but it is more expensive.
  • Zinc is the best choice for high-stress roofing environments, specifically those at greater risk of exposure to chemicals, pollutants, or saltwater air. It, too, is quite expensive.

Additionally, there are many different styles of metal roofing, which can essentially be lumped into one of two categories:

  • Exposed-fastener systems are more cost-effective and easier to install. They also come in a wide variety of different profiles.
  • Concealed-fastener systems (aka standing seam systems) are more visually attractive. Therefore, they are mostly reserved for architectural roofing applications in which roof surfaces are usually visible from the ground.

All metal roofs are constructed with either a low or steep-slope pitch—regardless of type or style. This is done to ensure positive drainage.

About the only drawback to a metal roofing system is its up-front cost. That said, metal roofs are not infallible. Still, most problems can be attributed to improper installation (specifically with the fasteners) or lack of general maintenance.

5. Liquid-Applied Roofing

Liquid-applied roofing (aka roof coating) systems are installed directly over existing roof surfaces. These systems cure to form a seamless, rubber-like, and watertight membrane that effectively restores and protects roof substrates from the sun and other elements.

The most common types of liquid roof coating are:

  • Silicone is the most popular roof coating chemistry on the market today. This solvent-based coating is best known for its exceptional ponding water resistance and UV stability.
  • Urethane (polyurethane) is a xylene-based coating best known for its superior strength, durability, and adhesion qualities. There are two types of urethane coating: aliphatic and aromatic. Each is suited for specific applications.
  • Acrylic coatings are water-based materials that are primarily used on metal roof surfaces. They offer excellent thermal reflectivity and durability. They also cost significantly less than silicone and urethane coating.

Essentially, liquid-applied coating systems minimize the sun’s harmful effects on roof surfaces. They effectively prolong service life, circumventing the need for total replacement.

A liquid coating system’s most significant benefit is its price point, costing about half as much as alternative types of roofing.

Liquid-applied roofing systems are warranted to last anywhere from 10 to 25 years. They can also be recoated numerous times during their lifespans, further extending their longevity.

Recommended reading: What Is Liquid Roofing, How Does It Work?

Honorable Mention: Spray Foam Roofing

Spray foam (SPF) systems are the best roofing solutions for cold-storage warehouses, hence their inclusion on this list.

Spray polyurethane foam is a plural-component material with exceptional R-value and waterproofing capabilities. These systems provide a seamless, lightweight, and highly durable membrane capable of resisting ponding water conditions.

Additionally, spray foam roofing systems are renewable and sustainable, producing little to no waste over their lifespan.

Recommended reading: Spray Foam Roofing: The Complete Guide

Warehouse Roofing Costs

Now that we have covered some of the most common types of warehouse roofing, let’s see how they compare in terms of cost:

System/material Low-end cost (per sq. ft.) High-end cost (per sq. ft.)
Modified bitumen $5.00 $12.00
Built-up $6.00 $14.00
Single-Ply $4.00 $10.00
Metal $3.00 $15.00
Liquid-Applied Roofing $2.00 $5.00
Spray Foam Roofing $5.00 $8.00

Conclusion

There’s a lot to consider when choosing a warehouse roofing system. All of the roofing types highlighted above are quality solutions, but knowing which is best suited for a specific roofing environment depends on a variety of factors (i.e., budget, climate, roof construction, building code requirements, etc.)

If you are in the market for a warehouse roofing system and would like to learn more about your options, click here to speak with an American WeatherStar service representative.