Chimney Waterproofing and Roof Duct Sealing
Chimney waterproofing and roof duct sealing deal with large penetrations: kitchen exhaust flues, generator and boiler chimneys, and the AC and extraction ducts that rise through a roof. Each one needs an opening cut through the sheets or slab. The duct vibrates, heats up and cools down, while the roof moves on its own cycle, and the joint between them eventually opens.
Leak Lock Insulation Contracting seals these openings with flexible membrane and fabricated flashings on metal and concrete roofs. Restaurant operators, factory and plant managers, and facility teams call us when water follows a duct down into the building, often arriving in the kitchen, plant room or production area below.
Signs of a Leaking Chimney or Duct Penetration
For example, clients contact us for one or more of the following reasons.
- Water running down the duct: drips appear on the outside of the ductwork indoors.
- Cracked collar sealant: the seal at the roof line has hardened.
- Loose storm collar: the skirt above the flashing has slipped.
- Rust streaks: corrosion on the flashing or the sheet around the opening.
- Gaps at square ducts: corners of rectangular ducts left open.
- Heat-damaged sealant: material near hot flues has burnt or shrunk.
Our Roof Duct Sealing Services
Duct Penetration Sealing
Membrane collar formed around round and rectangular ducts.
Chimney Flashing
In addition, fabricated metal flashings and storm collars fitted around flues.
Kerb Waterproofing
Raised kerbs around large duct openings sealed on all four sides.
Support Leg Sealing
Similarly, legs and brackets of duct supports sealed where they meet the roof.
Sheet Repair
Oversized or damaged openings closed with new sheet before sealing.
Corner Reinforcement
Also, extra membrane at the corners of rectangular ducts.
Our Chimney and Duct Waterproofing Process
Because every site is different, we adapt these steps to your chimney & duct waterproofing project.
- InspectionBefore anything else, we check the opening, flashing and the path the water is taking.
- CleaningThen, grease, dust and failed sealant are removed.
- Flashing WorkAfter that, flashings and collars are repaired or newly fabricated.
- Membrane SealingAs soon as that is done, EPDM membrane is bonded from the roof up onto the duct or kerb.
- Water TestFinally, the penetration is water tested where possible.
Materials & Methods
Penetrations are sealed with EPDM membrane and bonding adhesive, combined with metal flashings made to the size of the duct. On hot flues the detail is designed so that the membrane is kept away from high-temperature surfaces, with a metal flashing and storm collar doing the work closest to the flue.
In short, the work includes the following.
- EPDM membrane collars and upstand strips
- Fabricated flashings and storm collars
- Membrane kept clear of hot flue surfaces
- Closure of oversized roof openings
Why Choose Leak Lock for Chimney & Duct Waterproofing
Above all, clients choose us for these reasons.
- Membrane and metalwork together: one team seals the opening and makes the flashing.
- Any shape or size: round flues, square ducts and multi-duct kerbs are all detailed individually.
- Safe working at height: in addition, our team uses fall protection and controlled roof access for all chimney and duct waterproofing work.
- Clear paperwork: as a result, you know the scope, price and warranty terms for the chimney and duct waterproofing before we start.
Areas We Serve
We seal chimney and duct penetrations on roofs in Dubai, Abu Dhabi, Sharjah, Ajman, Umm Al Quwain, Ras Al Khaimah and Fujairah. As a result, one team can handle chimney & duct waterproofing at all of your sites.
Dubai Abu Dhabi Sharjah Ajman Umm Al Quwain Ras Al Khaimah Fujairah
Chimney & Duct Waterproofing FAQs
Questions about chimney and duct leaks. Also, you can call us with any other question.
Rain hits the duct above the roof and runs down its surface. If the collar or flashing at roof level has opened, the water continues along the duct into the building.
Yes. The detail uses a metal flashing and storm collar near the flue, with the flexible membrane positioned away from the hottest surface.
No. The work is carried out around the duct in place.
Yes. Groups of ducts are usually enclosed with a kerb and flashing, then each duct is sealed where it passes through.
Yes. Grease is cleaned off first so the adhesive can bond, and the seal is formed around the duct at roof level.
Related Services
Pipe Penetration Waterproofing
Collars and membrane detailing around pipes through the roof.
Read MoreSmoke Vents Waterproofing
Watertight sealing of smoke vent frames and kerbs.
Read MoreMetal Roof Waterproofing
Sealing of laps, screws and ridges on metal sheet and sandwich panel roofs.
Read More
In addition, you can see all of our waterproofing and fabrication services. Otherwise, contact our team to discuss your project.
Seal Your Chimney or Duct Opening
Send a photo of the duct at roof level. We will inspect it and quote for the flashing and sealing work. After that, we will arrange a suitable time to visit.