Choosing a Pump Cover: Clamshell Fiberglass vs. Aluminum Pump Covers

huge fiberglass enclosure is damaged

This may come as a surprise, but there aren’t many options on the market for pump covers protecting against weather, vandals and animals. One popular solution is an inexpensive fiberglass clamshell design, providing easy access to the pump for quick visual inspections.

If the occasional visual inspection is all that’s needed, and no service or repairs need to be made to the pump, a fiberglass clamshell pump cover would probably do the trick. In the real world, though, we know that there’s far more to factor when it comes to protecting sensitive pump equipment. What’s more, while a clamshell fiberglass cover might have been sufficient for mild climates in the past, changes in weather patterns and increasingly extreme weather events throughout the country should give people pause when they are considering a pump cover solution.

We haven’t been shy about our feelings toward fiberglass in the past. Today, there just aren’t any compelling reasons why you should consider fiberglass over aluminum in any use case.

Fiberglass Versus Aluminum Pump Covers: A Quick Review

Many pump covers need to be modified or altered to meet custom specifications. Fiberglass, being brittle, requires specialized equipment and skilled, trained eyes and hands to fit to these specs, all while requiring ideal weather conditions. Once installed, fiberglass will fade, crack and deteriorate, simply from normal exposure to ultraviolet light over time. Relative to aluminum, it is fragile and is subject to shattering.

On the other hand, aluminum is easy to work with; adding windows, panels, louvers, vents and other accessories is relatively simple. The aluminum pump cover can be mounted to a pump skid, and piping penetrations during installation can be easily performed. Marine-grade aluminum is ideal in all environments and can withstand normal weather patterns for up to and, in some cases, in excess of 30 years. Our partnership with PAC-CLAD means that the color of your pump cover is baked into the aluminum, resisting fading or color loss.

Download the enclosure design guide with the top 5 enclosure design  considerations

Let's Talk Clamshell Pump Covers


The most obvious difference between clamshell fiberglass pump covers and aluminum enclosures is ease of access. If pump equipment does need maintenance, an enclosure with removable modular panels will always work better. With a removable roof, pumps can be lifted entirely in and out of enclosures.

There are other key differences between clamshells and modular pump covers. For one, clamshell enclosures typically ship pre-assembled. Modular enclosures ship flat and are assembled onsite. This might be unexpected, but a fiberglass enclosure is often heavier than a similarly sized aluminum pump cover. A buyer may be looking at fiberglass as a value play, but there’s a stealth cost in paying more for shipping because the fiberglass cover takes up more space, and also weighs more.

Speaking of shipping, because clamshells are typically made of fiberglass, you'll have to worry about damage in transit. Sometimes pump covers arrive cracked.

Another major distinction between clamshell enclosures and Safe-T-Cover is the insulation. We use polyisocyanurate panels, which are laminated to a glass fiber-reinforced facer on each side. Most clamshells have spray-in insulation, which has a rough consistency that can trap dirt and other debris and, again, is prone to cracking and damage. Modular enclosures, like ours, mean that any panel can be a removable panel or door, and that equipment can even be mounted to a hinged panel for quick access. You can't exactly get away with mounting a control unit to the side of a clamshell pump cover.

Get What You Really Need

At first, a clamshell fiberglass pump cover may sound like a cost effective solution to your equipment protection problem. You probably want to just get that decision out of the way, right? 

The savvy buyer needs to take the long-term view when it comes to protecting pump systems. That equipment is likely to be in place for years or decades. In order to properly service it and conduct any needed repairs, you need better access than a clamshell provides. Additionally, a pump cover should fit the equipment perfectly, which means custom elements or penetrations may be needed. Finally, in order to save money now and in the long run, buyers should look to purchase the most durable option, one that will maintain its looks and provide superior protection throughout its entire lifecycle.

The choice is clear. The choice is Safe-T-Cover.

pump enclosure

Related Posts

What Are the Size Limits for a Custom Enclosure?

Reasons to Consider a Custom Enclosure Solution

From the Field: The Benefits of Genuine California Redwood Bracing in Safe-T-Cover Enclosures

Winterize Your Backflow In Eight Steps (or One)

Aluminum Enclosures and Concrete Pads: Total Security and Confidence

LEEDing the Way: Enclosures and How LEED Can Benefit You

Built to Prevent Enclosure Color Fading: The Science of Safe-T-Cover

Low Price, High Cost: Fiberglass Enclosures Are Built to Fail

Lighting and Your Aluminum Enclosure

Beyond Aluminum Enclosures: Our Commitment to Corporate Responsibility

Protection from Sound and Fury: Safe-T-Cover Enclosures and Noise Dampening

Aluminum Pump Enclosures vs. Pump Packages

Standing Out By Blending In: Safe-T-Cover Enclosures Made to Order

From the Field: June 2022

Air Cooler Enclosure Solves End-User Problem

VE Sales (MI) Case Study: Above-Ground Oil Water Separator

Follow This Custom Enclosure Design Checklist To Protect Your Equipment

Selecting the Right Heater for a Backflow Cover

Hinged Access Panels Keep Things Safe in Windy Conditions

5 Ways Panel Design Equipment Covers Offer Superior Flexibility


Project Engineer vs. Maintenance - A Valve Cover & Pump Cover Tug-of-War

How To Size A Custom Backflow Enclosure

How To Ensure Your Insulated Backflow Enclosure Stays Warm

Safe-T-Cover To Discuss Flood Risks at AWWA Conference

The Best Way To Protect Your Backflow Preventer From Copper Theft

Backflow Preventer Testing Should Be Required for Safety According to Expert

When You Should Use Backflow Theft Prevention Cages

What Made Fiberglass Backflow Enclosures So Popular?

Enclosures: Wear, Tear, and Fiberglass Repair

Can Wooden Storage Sheds Work as Waterworks Equipment Enclosures?

Fiberglass Shelters vs Aluminum Shelters - What's the Life Cycle Cost?

Which Do You Need - A Cage or Enclosure For A Backflow Preventer?

Enclosures Help With Loud Equipment and Pump Insulation - Keep Your Sanity

When Is A Backflow Enclosure Cage No Longer Enough?

How Much Do Custom Aluminum Enclosures Cost?

Case Study: Large Pump Covers and Air Conditioning Pump Enclosures

Top 8 Questions About How To Best Shelter Equipment

Choosing a Cover: Grade Enclosure Manufacturers On These Abilities

Case Study: Pump Enclosure with Variety of Custom Features

Multiple Backflow Preventers in One Aluminum Building

An Engineer's Guide to Custom Industrial Enclosures

Case Study: Custom Equipment Shelter replacements

Case Study: Heated Industrial Enclosures for Fire Water Storage Tank

How to design & Buy a Pump Enclosure

Get the free, editable checklist.



Have a question about a backflow preventer enclosure?
Click the contact us button below and one of our experts will be able to help with your specific enclosure needs.