Pipe Boot Best Practices for Standing Seam Metal Roofs

Use Proper Materials

When installing a pipe boot to a standing seam metal roof, you should always use the proper tools and materials for the project to avoid roof leaks and damage later on. This is not the time to choose a lower quality material that is cheaper.

When purchasing a plumbing vent pipe boot, you should make sure that it is rubber and made to be used on metal roofs. The proper pipe boot or pipe flashing is made of an EPDM rubber with a bonded aluminum band that will form a compression seal of the surface of the metal tool panel. Another type of roof flashing with materials like lead and copper has a shorter life span and can corrode the metal roof system.

An EPDM rubber boot can generally withstand temperatures of up to 212 degrees Fahrenheit. If your metal roof deck will be exposed to higher temperatures, you chose to use a high-heat silicone-based plumbing vent boot which can generally withstand up to 437 degrees Fahrenheit.

For sealants, you should only be using butyl tape for the plumbing vent flashing base and caulk sealing to secure the plumbing vent boot to the pipe. Other types of sealants can risk metal roof leaks or corrosion. Always be sure to use long-life fasteners for longevity and beware of zinc-plated fasteners that are not fully weatherproof.

For every material that you use, you should be sure that it is compatible with the roof manufacturer. Pipe boot best practices include double-checking the quality of tools and materials to make sure that it is built to last because roof leak repair can be a costly headache.

Clean the Pipe Penetration

Before you can seal the boot to the metal roof and vent pipe, you should always make sure that the pipe penetration is clean. Sometimes vent pipes are rusty or have tar build-up. If this is the case, you should chisel the debris off of the pipe to clean it off.

You can also seal a pipe sleeve over the vent pipe for a cleaner aesthetic and to avoid rust leakage onto the metal roof. When choosing a pipe sleeve, it is best to pick one that is made of the same metal material as the roof. Also, ensure that it fits snuggly around the pipe penetration and is sealed tightly.

Cutting the Plumbing Vent Boot

Cutting the plumbing vent boot is often the step where a roofing contractor will go wrong. When cutting a rubber boot to fit the pipe penetration, you have to be careful to cut it to the perfect size where it fits snuggly around the shaft of the pipe.

If the roofing contractor cuts the rubber boot too wide, then it won't fully seal to the pipe and gapping will leave the roof vulnerable to leaks. If the boot is cut too narrow, then when you try to slide it onto the roof penetration, it can rip, and then you will need to buy a new one.

To avoid these common mistakes, the installer should cut the vent boot one ring inside the diameter of the pipe so that it fits tightly around the vent pipe without ripping. Next, slide the boot down the pipe penetration and mark where the top of the boot meets the pipe and where the base of the boot meets the metal roof panel to prepare for the next step of sealing.

Securing the Pipe Boot to the Metal Roof

When securing the pipe boot to the metal roof, you should use butyl tape to secure the base to the metal roof surface and caulk sealants to seal the top of the boot to the pipe. Line the base of the pipe boot with butyl tape and put a ring of sealant around the pipe shaft with a caulking gun where you marked the top of the boot. Then you can slide the boot down the pipe to fit snuggly around the bead of caulk.

Next, when you seat the fasteners down to secure the base of the pipe boot to the metal roofing panel, you should see the butyl tape seal pushing out a little bit. When drilling in the fasteners, you should also ensure that you don't drill them down too far because you will risk tearing the rubber pipe which would set you back to starting all over with a new boot.

In any case of installing a pipe boot to a metal seam roof, you should always consult with a roofing professional and/or a metal roofing company for the best metal roofing and pipe boot practices. It is best to have a professional complete the project but if you are a determined DIY building owner, then make sure you have close access to expert advice in case something goes wrong.

Remember to prioritize your safety in all metal roofing installation procedures and always choose top-quality tools and materials. We carry different Dektite pipe boots for your metal roofing project needs. Contact us with any questions about our products.