How-To: Selecting Rooftop Mounted Mechanical Equipment Screening

America’s Fence Store provides you with a complete guide on selecting rooftop mounted mechanical equipment screening/enclosures. We’ll guide you through selecting design, materials, and products.

OVERVIEW

Use this How-To guide to help determine:

when you need rooftop mechanical equipment screening
design of your screening
selection of quality materials.

For over twenty years, PalmSHIELD has worked with contractors, designers, architects, engineers on rooftop equipment screening; these many decades of experience have provided us with expertise on the best screening designs and materials—not to mention the best method to use screening to complement building aesthetics.

MECHANICAL EQUIPMENT

First, what constitutes “mechanical equipment?” Mechanical equipment potentially includes any device that supports cooling, heating, electricity, water supply, and waste management. Examples include: containers, generators, compressors, breakers, compactors, chillers, meters, condensers, and HVAC.

These types of equipment are frequently located on rooftops, where they are subject to greater risk of wind damage and within direct line of sight of pedestrians.

Do I need a permit to install mechanical equipment screening?

Rooftop mechanical equipment screening requires a building permit and, in most cases, community design approval. (The screening needs to match not only the building envelope but the surrounding area.) Refer to your city planning department and local building inspector for the necessary approval process requirements.

Besides a building permit, what else do I need to install mechanical equipment screening?

Building permits are often used in conjunction with a set of professionally prepared drawings. These drawings, put together by an architect, need to be in line with community appearance standards and guidelines for rooftop mechanical equipment screening. Check these community-set guidelines, which should address material selection in accordance with the design of surrounding buildings as well as public view considerations. The majority of communities employ strict guidelines for rooftop equipment screening and architectural screening, and use a “line of sight” approach regarding height, location, and coverage.

Our How-To guide does not overrule community standards. Always consult with your city planning department and local building inspector.

CONSIDERATIONS FOR MECHANICAL EQUIPMENT SCREENING

Designers of rooftop mounted mechanical equipment screening need to consider the following:

Material color, scale, and usage for building envelope material. Rooftop equipment screening should be compatible with the existing building envelope’s structure, style, and color. If roof lines are vertical, for instance, consider using vertical slats or vertical louvers for your mechanical equipment screening.
Line of sight. During the design phase, take into consideration how the screening will appear from all possible vantage points. For example: for buildings near elevated structures or roads, rooftop equipment screening featuring a roof or overhang may be necessary. On the other hand, for buildings taller than their immediate surroundings, rooftop equipment might not even be required as it won’t be visible from any vantage point.

Always consult your local codes on the matter of vantage points.
The mechanical equipment in need of screening. Taking into account space, height, and ventilation requirements, it might not be practical—or even possible—to screen all rooftop equipment for your project. In some cases, equipment might need to be painted in accordance with local appearance standards. In the case of some stacks, a required height is in play to achieve recommended ventilation. These stacks can be framed in materials that match the surrounding building envelope.
Structural considerations. Not all rooftop mechanical equipment screens have been designed and engineered in a self-supporting fashion. What’s more, not all are designed to be attached to rooftops. For this reason, a structural engineer should be tasked with calculating wind load according to conditions in your project site’s area. Structural engineers can also provide stamped drawings and performance data.
Visibility. One of the selling points of PalmSHIELD’s rooftop mechanical equipment screening is that it can be modified to achieve the amount of visibility desired/required. For example, louvered panels—our most common rooftop mechanical equipment screening design—can offer 80% or 100% direct visible screening. Other panel infills available from PalmSHIELD can similarly be modified.
Openness. Openness consists of the space between infill elements in your screening, through which air can flow. The openness of your screening setup is partly determined by the above mentioned visibility and direct visual qualities.

In many cases, rooftop mechanical equipment will have a recommended free air amount. Community guidelines might also require a specific amount of air flow.
Infill design and selection. Here at PalmSHIELD, we offer numerous options on rooftop mechanical equipment screening infill—so that you can pick screening that will match community appearance standards, building envelopes, and requirements on visibility and openness. Our screening products feature picture frame designs.

The most common designs for rooftop screening include:
Louvers. PalmSHIELD’s louvers can be customized to add or decrease both visibility and airflow. Our most common horizontal louvered option features 100% direct visual screening and 64% openness. PalmSHIELD’s louvered infills come in the following forms: horizonal, vertical, and diagonal.
Slats. Highly customizable, slats are a popular option for mechanical equipment. PalmSHIELD’s mechanical equipment screening is available in the following materials: composite, aluminum, and vinyl.

Slats are available in tubular or solid infills; they can be positioned horizontally, vertically, or diagonally. Another option is the shadowbox pattern, which can provide a near 100% direct visual screening while retaining a certain degree of openness.
Perforated screening. These metal sheets come in a variety of stylistic patterns and hole sizes, including circles, squares, stars, hexagons, and custom designs.
Other. Check out PalmSHIELD’s product page for a complete list of our fully framed products—all of which can be utilized for rooftop mechanical equipment screening.

After evaluating the needs of your mechanical equipment, PalmSHIELD’s designers will go over material selection and products for the screening. Below are five common options for rooftop mounted mechanical equipment screening and enclosures.

1). STRUCTURAL STEEL FRAMEWORK

The most common material used in constructing commercial buildings, structure steel is frequently matched with structural steel mechanical equipment screening. This particular screening type is also often within the steel contractor’s wheelhouse: welded and installed in early phases of the construction project.

Typically, these rooftop mechanical equipment screens are integrated into the building’s framework, extending below the rooftop materials used in connecting structural steel within the building. Structural steel rooftop screening cannot be used in retrofits or additions to your building, as they are part of the actual framework. In most cases, if the equipment screening’s added during an addition or retrofit, it’s because the screening was not originally considered when the building was being constructed.

Advantages:

Enhanced strength. Due to being welded to integral framework, structural steel equipment screens are especially strong and durable.
Wider coverage. PalmSHIELD can fabricate structural steel equipment screening to cover both wide and tall areas.

Disadvantages:

Water damage. Creating watertight seals around the square tubes extending beyond the roofing is rather difficult. Consequently, this type of screening is more vulnerable to water damage.

What’re more, any water that does enter the steel tubing has access to the building itself, as the tubing provides a direct access line to the building framework. Screws, pin holes, fasteners, poor welds, etc. also increase the odds of water damage.

Rust expenses. Because this type of screening is vulnerable to water damage, it is also prone to rust development. PalmSHIELD recommends hot dip galvanization, which tends to run up costs. It is worth inventing in, as a steel mechanical equipment screening suffering from rust damage can result in roof staining and may violate community appearance guidelines.

Also, over time, a rusting equipment screen could eventually give in and fail.

Relocation expenses. Unlike mechanical attached systems—which are easily removed and reinstalled—the process of relocating structure steel rooftop mechanical equipment screening tends to be costly. This is due to the screening being built using integral framework.

Difficulties with changes. Building renovations and new tenants may result in additional screening being required. The exiting screening could result in complications.

Lack of warranty. The coatings and the screening itself are not covered by manufacturer’s warranty—as it is welded on site by a structural steel contractor.

2). STEEL STUD FRAMEWORK

Many retrofit applications feature rooftop mounted screening with steel stud frames—typically installed by carpenters, sheet metal contractors, roofers, and drywall installers.

Note: This option is not engineered by a manufacturer and does not come with a manufacturer’s warranty. Because of this, it is typically not within the scope of a single trade.

Advantages:

Enhanced longevity. Because steel stud framework is hot dip galvanized, it will last a long time, even in exterior settings.
Simple installation. Because steel stud framework can be cut, assembled, and installed in the field, installation is simple.

NOTE: Field welding on rooftops is not recommended due to the increased likelihood of fires. Drips from the welding can bore holes in a rooftop.

Disadvantages:

Difficult attachment. Typically, steel stud framework is mounted to wooden sleepers, which are bolted to the structure beneath the rooftop membrane. This attachment process tends to be difficult.

It is likewise difficult to keep this method completely watertight during the mounting process.

Disrupted water drainage. The wooden sleepers used in mounting can cause buildup of debris, impeding water drainage and potentially roof failure.

3.) WOODEN ROOFTOP SCREENS

The wooden—or “stick built”—rooftop mechanical equipment screening system is nonengineered, utilizing wooden posts, supports, infill, etc. In most cases, a lattice effect is employed to provide visual screening while also permitting airflow. However, this option is not recommended due to lack of protection from the elements on exposed areas such as rooftops.

NOTE: Wood is frequently used due to availability and affordability. However, it has drawbacks. Because of its not-very-pliable material and lack of engineering, wood framework is not recommended as a long-term solution. It can potentially fail under minimal wind loads. Although often used by contractors to save on costs, wooden screening does not come recommended by PalmSHIELD for rooftop applications of any kind.

Advantages:

Convenience. Wood framework is affordable and can be easily assembled in the field.
Aesthetic appeal. Better than most materials, wood matches building envelopes and surroundings. If your site and the surrounding environment features a heavy amount of wood, consider an engineered metal system complete with composite or vinyl panel infills whose texture mimics the appearance of wood.

Disadvantages:

Regular maintenance. Over time, wood tends to warp, bow, and sag. Properly maintaining wood requires diligence.
Difficult installation. Like steel stud framework, wood sleepers cannot guarantee a watertight installation. Rooftop attachment can be difficult.

4). MECHANICAL EQUIPMENT MOUNTED SCREENING

With this option, a rooftop mechanical equipment screen can be directly mounted to the rooftop mechanical equipment. Screening panels are fastened to the equipment through an equipment exoskeleton and trussing system, which are provided by the equipment manufacturers. This trussing system’s offered by many manufacturers as an add-on, or attachment points on the screening itself may be engineered for load bearing.

Mechanical equipment mounted screening is excellent for PalmSHIELD’s fully framed equipment screening panels. Provide attachment points needed for the panels and our highly trained staff will fabricate a truss system for quick and efficient attachment.

Advantages:

Easy installation. Especially when utilizing PalmSHIELD’s rooftop mounted equipment screen panels, this process is fast and efficient.
Reduce leakage. Mechanical equipment mounted screening does not necessitate penetrating the roof membrane during the mounting process.
Code adherence. This type of mechanical equipment screening meets the requirements of most municipality guidelines and codes.

Disadvantages:

Possible limitations. Mechanical equipment mounted screening may not be possible if the equipment manufacturer does not offer a surrounding trussing system, mounting points, or exoskeleton.
Wind loading. While this type of equipment mounting is an engineered option, it is important to consider wind loading. Wind load added to the framework is inevitable when the screening extends above the equipment itself. The framework is attached directly to the equipment, so wind loads on the equipment can potentially be severe. This is a problem, as the equipment and its attachments are not engineered to withstand wind loads of such strength. Refer to a registered structural engineer in your jurisdiction for proper wind loading.
Limited access. Sufficient access with mechanical equipment mounted screening may not be sufficient. To ensure access to mechanical equipment units, consider PalmSHIELD’s options on heavy duty gates.

5). PALMSHIELD INDUSTRIAL ROOFTOP SCREENING

Highly popular for designing engineered rooftop mechanical equipment screening solution are PalmSHIELD’s fully framed product options featuring a selection of visibility, airflow, and aesthetic options. Our panels are fully framed in aluminum, capable of being attached via structural steel options, mechanical equipment mounting options, or propriety rooftop mounting support systems. PalmSHIELD can provide panels to attach to the rooftop the way the buyer chooses. We can provide our exclusive rooftop mounting framework. We can also work with you to design panels to mount directly to mechanical equipment at the attachment points.

Our rooftop mounting support system features watertight equipment rails. The framework and kickers mount directly to the rails, resulting in an engineered system with strong resistant to wind load. This resistance cannot be matched by one-off or stick-built rooftop screening: an economic option allowing for numerous custom layouts and designs.

For attaching equipment or equipment framework, PalmSHIELD offers our cantilevered trussing system, along with all necessary brackets and hardware—which can be customized for the needs of your particular project.

To resist high wind loads on rooftops, our rooftop mechanical equipment screening is extremely robust. We recognize that damage to/loss of mechanical equipment can be severe to a building’s use.

Advantages:

Customization. PalmSHIELD customizes rooftop mechanical equipment screening to the needs of the individual project.
Long lasting. Engineered for longevity, our screening is robust and boats a greater lifespan than stick-built options.
Aesthetics. PalmSHIELD’s fully framed panels options are available for rooftop installation. This means we can customize the aesthetics of your panels to match community appearance standards while controlling airflow and visibility.
Compatible with slopes. This is not an option available from most manufacturers. Another reason why PalmSHIELD is the choice contractor of mechanical equipment screening.
Picture frame design. As the only rooftop screening manufacturer providing structural picture frame design to panels, PalmSHIELD is also one of the few manufacturers to offer rooftop appliance gates.
Watertight. Helps avoid costly damage by preventing water leakage.
Economic. Compared to other rooftop attachment methods, PalmSHIELD’s rooftop mountain rails are more economic.
Simple installation. Easy, efficient installation is offered across the board for PalmSHIELD’s applications involving rooftop mechanical equipment screening panels.

Disadvantages:

Not compatible for short-term projects. Because of their robust design and engineering, PalmSHIELD’s products are built to last. They are not “one-off” or ideal for short-term setups. It’s worth noting that most contractors and designers are accustomed to working with short-term projects. Fortunately, PalmSHIELD offers CAD drawings, site specific shop drawings, step-by-step installation guides, and expert analysis to help contractors and designers.
Less cost competitive. PalmSHIELD is more costly than non-engineered one-offs and stick-built rooftop equipment screening. However, you should remember the long lifespan of our products, the ease of installation, the convenience of shop drawings for designers and contractors, etc. when factoring in cost. One-offs and stick-builts may cost less, but they don’t have the incredible features PalmSHIELD’s products do.

After height, location, material, style, and product type are figured out, the ideal design shall be finalized according to mechanical equipment configuration and needs. Layout takes into account line of sight and other design factors:

Clearance. Most manufacturers for mechanical equipment recommend ideal amount of clearance, so that equipment will be unobstructed by material. They will also recommend airflow for the equipment to function properly. Please follow the manufacturer and follow their recommendations, maintenance documents, and follow your area’s local codes.
Accessibility. In most cases, local codes require specific accessibility to mechanical equipment. Gates, doors, access points, etc. are typically required on the control side of the enclosure housing mechanical equipment. The gates are almost always required to open outwards.
Number of screens. In some cases, local codes require continuous screens rather than multiple individual screens.
Openings. Make sure your designers take into account vents, ducts, wiring, pipes, etc. This is needed for direct access to mechanical equipment, and the rooftop screening needs to be designed to go around these areas. Locations of all variables must be communicated to the provider of your mechanical screening. Accurate fabrication according to these variables is a must.
Existing parapet walls. Existing parapet walls may limit the amount of screening needed for 100% direct visual screening. All lines of sight and local equipment enclosure coding needs to be consulted by your designers.

Once you’ve reviewed everything listed in our guide above, you are ready to contact your rooftop equipment screen manufacturer. The information we’ve provided should give you an idea of the design, layout, and styles required. Provide this information to the manufacturer of your choice for the proper pricing. If unsure about anything in our guide, consult your manufacturer. They should provide a full set of elevation views, fabrication drawings, product details, and engineering specifics. Use these to support your submission to community planning authorities.

PalmSHIELD hopes our guide to selecting rooftop mechanical equipment screening has proven useful to you. For further information regarding product design and selection, visit www.palmshieldlouvers.com and contact us for assistance.