This Dektite pipe flashing sizing installation guide covers every Dektite product type, how to choose the right size flashing, and how to install it correctly for a strong watertight seal on metal roofs. Dektite is the standard for sealing pipe penetrations on metal roofs, used by roofers worldwide because it flashes almost any pipe penetration cleanly without custom sheet metal work.

What Is Dektite?

Dektite is a brand of roof pipe flashing made by DEKS. A Dektite flashing consists of a flexible base, such as aluminum or rubber, and a rubber or silicone cone. The cone stretches over and seals around the pipe exterior to create a strong watertight seal without caulk alone that may crack and fail. Dektite flashings seal hot and cold pipes on metal roofs and can flash awkward or large penetrations that many other flashings cannot accommodate. Dektite is available in a wide range of products for different applications — the right one depends on your roof type, pipe size, roof pitch, and whether the pipe carries hot or cold media.

Dektite Product Lines

Dektite Original

The standard flashing for most metal roof applications, Dektite Original seals hot and cold flues on metal roofs and provides a strong watertight seal for standard round pipe penetrations. Dektite Original withstands temperatures from -58°F to 239°F or higher, depending on the material, making it suitable for most HVAC pipes, plumbing vents, and moderate-temperature flues.

Dektite Premium

Dektite Premium features a highly durable EPDM cone with a flexible square base for better sealing on corrugated or standing seam metal roofing profiles. The flexible aluminum strip around the base allows the flashing to conform to almost any pipe penetration profile — including pipes not centered over a corrugation valley.

Dektite Ezi-Seal

Dektite Ezi-Seal uses a non-absorbent sponge gasket for sealing instead of requiring applied silicone sealant. This flashing eliminates the need for additional silicone sealant during installation — the integrated gasket provides the seal when the base is compressed and fastened against the roof surface. Dektite Ezi-Seal is ideal for a quick watertight solution where silicone application adds time or where installation in wet conditions makes sealant application impractical.

Dektite Retrofit

For re-flashing existing pipes where the original watertight flashing has failed, the Dektite Retrofit split base wraps around existing pipe penetrations, allowing installation without removing the pipe. Dektite Retrofit products are the original watertight flashing solution for roofing projects where pipes cannot be disconnected; suitable for access pipes, cold flues, and standard plumbing vents.

Dektite High Pitch

Dektite High Pitch is designed for roof pitches from 35 to 65 degrees — steeper than standard roof flashing products can accommodate. Dektite High Pitch is used on steep residential roofs, commercial buildings with architectural metal roofing, and agricultural buildings where steep slopes shed snow loads.

How Long Do Dektite Products Last?

Properly installed Dektite flashings typically last 15–20 years on metal roofs, and sometimes longer. The rubber cone is the lifespan-limiting component as UV and weather exposure degrade the material over time. EPDM rubber (the standard material) performs well across a wide temperature range and withstands weather exposure better than other rubber materials. Silicone rubber cones last even longer in high-UV and high-temperature applications. To make your Dektite flashings last, inspect penetrations every 5–7 years for cone cracking or base seal deterioration, and replace any that show visible degradation before leaks develop.

What Sealant Should You Use with Dektite?

The base of Dektite flashings should be sealed with a continuous bead of silicone sealant where it contacts the roof surface. On most Dektite products, sealants should also be applied around the top of the cone where it meets the pipe to complete the watertight seal. Use a high-quality exterior-grade silicone or polyurethane sealant rated for metal roofing applications; do not use general-purpose caulk, which degrades quickly under UV exposure and temperature cycling on a metal roof. Exception: Dektite Ezi-Seal products do not require silicone — the integrated sponge gasket provides the seal. Do not apply sealant to the base of Ezi-Seal products unless instructed by the manufacturer, as it may interfere with the gasket compression.

Can You Paint Dektite?

EPDM Dektite products can be painted with a flexible, rubber-compatible paint to match the roof color. Standard exterior paints may crack and peel on the flexible cone, so specialty EPDM- compatible paints or metal roof coatings that bond to rubber are the correct choice. painting doesn't affect Dektite performance — it's a cosmetic option only. The aluminum base can be painted with any metal primer and topcoat compatible with exterior aluminum.

Dektite Installation: Step by Step

1. Size the Dektite. Start by purchasing the Dektite flashing that accommodates your pipe size. Then, to ensure a snug, waterproof seal, cut the Dektite cone slightly smaller than the pipe — about 20% smaller than the pipe's outer diameter. This creates the tight fit that seals against the pipe to prevent leakage
2. Clean the surface. When installing Dektite, the roof surface must be clean and dry. Dirt and moisture prevent the sealant from adhering to the metal roof panel.
3. Lubricate the cone. Use water as a lubricant when sliding Dektite down the pipe, avoiding soaps and oils, which degrade EPDM over time. Water allows the cone to slide onto the pipe without tearing.
4. Orient the base. For square-base flashings, the base must be oriented diagonally with a corner pointing upward to allow water to flow around it and prevent pooling behind the base.
5. Apply sealant and fasten. Apply a continuous bead of silicone to the underside of the base perimeter and smooth the base against the surface. Secure the base with long-life self-drilling roofing screws or pop rivets if screw access is difficult.
6. Seal the cone top. Apply sealant around the top of the cone where it meets the pipe to complete the seal.

Sizing Reference

Dektite Product	Temperature Range	Best Application
Dektite Original	-58°F to 239°F	Standard HVAC, plumbing vents, cold flues
Dektite Premium	-58°F to 239°F	Irregular penetrations, aluminum strip for conforming fit
Dektite Ezi-Seal	-58°F to 239°F	Quick install, no sealant required
Dektite High Pitch	-58°F to 239°F	Steep roofs of 35–65 degrees
Dektite Retrofit	-58°F to 239°F	Re-flashing without removing pipe

Shop Dektite Pipe Flashings at jakesales.com

Find the complete Dektite range — Original, Premium, UEC, Ezi-Seal, and Retrofit — along with self-drilling roofing screws and pop rivets at jakesales.com. Get a strong watertight seal on every pipe penetration.