Top Considerations When Roofing Around (and Under) Industrial Pipe Networks

August 12, 2021

Industrial roofs are often covered with a maze of pipes. This creates unique challenges and requires special considerations when it comes to reroofing and roof maintenance, for both the building owner and the roofing contractor. (Read about the safety hazards here).

Expect it to Take More Time & Money

Tearing off and installing a new roof when a congested pipe network is present increases labor, project duration, and costs. Pipes have to be lifted carefully to remove the roofing system underneath. “When we walk up to evaluate a roof and see pipes on racks, we’re going to count at least an hour to get the roof out from underneath each stand,” says Timm Haefner, Vice President Construction, D. C. Taylor Co., Cedar Rapids, IA. Every penetration must be flashed properly and even if the contractor is using pre-manufactured boots, it could take up to an hour (or more) to ensure a watertight seal for each penetration. This added time means larger project costs.

Not all Pipe Supports are Created Equal

“Stands or supports range in sizes, structure, and material. The weight of the piping will determine what type of support is required underneath it,” explains Mike Stickney, Vice President National Account Manager, D. C. Taylor Co., Cedar Rapids, IA.

If pipe supports (vs. stands) are ideal, options range from wood to plastic and rubber. “Most customers use wood nailers that are 2-in. by 4-in. or 4-in. by 4-in. They secure the pipe to the nailer with a pipe clamp (muscle clamp) along with bolts and then put a piece of membrane underneath,” says Haefner. While wood is the most popular choice (and least expensive), it’s not without disadvantages.

“Manufactured supports last longer and are more efficient than wood,” says Stickney. “The wood deteriorates over time. Manufactured supports wear better.” If you choose wood, there is a way to extend their life. “Your roof contractor can encapsulate them in membrane,” adds Haefner. Carefully weigh the time and material added to your project to determine if a manufactured support is more cost effective though.

Improper Installation Can Damage the Roof

“I’ve seen stands being used for piping that are crushing the roof. They need to go down to the structure, not sit on the roof,” says Stickney. Crushed insulation at the base of a pipe stand (especially if there is no coverboard installed) can cause deflection; this leads to ponding water, deterioration of the membrane, and weakened seams. To prevent this, Stickney offers the following advice: “If you have heavy piping, use wood blocking under supports that goes down to the steel deck or purlins.”

Likewise, failing to space the supports appropriately can cause significant problems – either in the form of a broken pipe or roof damage. “If you don’t distribute the weight, you can ruin the deck,” warns Haefner.

Most non-penetrating pipe stands come with a support (or slip) sheet under each leg. “A slip sheet or added layer of membrane under the support provides a layer of protection. It’s a barrier that doesn’t cause friction and a hole over time,” says Stickney. Without this extra layer, moving or vibrating pipes can cause wear to the roofing membrane.

Flash Penetrations Right and Watch for Problems

When reroofing is underway, make sure that penetrations are flashed in accordance with the roof system manufacturer’s instructions, using material compatible with the roofing membrane. Doing the job right at the onset will reduce the likelihood for problems later. Also, be mindful that the hole in the deck that the pipe is threaded through is usually bigger than the pipe itself; this means that as your old roof is being torn off, some debris may enter the building.

Regardless of if field-wrap or pre-manufactured flashing was used, and especially if pitch pans were unavoidable, maintenance is key. Whether because of building movement caused by thermal activity or vibration from equipment, when piping moves, flashing can pull away.

Don’t Neglect to Inspect

Penetrations can be a source of leaks if not maintained properly. Pipe supports can pose similar problems. Debris from a storm can get caught under or around supports, wood supports can rot or give home to insects, and supports without a slip sheet can damage the membrane. High winds can wreak havoc on piping and supports that aren’t secured in place. “If pipes are not anchored correctly, they could slip off in high winds or blow off the roof, causing injury or damage to the membrane,” says Stickney.

Regular routine inspections can check the condition of the roof system and penetration flashing as well as the stability of the pipe supports and stands. The best way to avoid problems is to catch them early.

Contact D. C. Taylor Co. today at 319.731.4118 to schedule a roofing service.

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