Project Case Study: Advanced Flat Roof Waterproofing in Cork City
Over years of facing the relentless Cork weather, traditional flat roof felt can perish, bubble, and allow water to penetrate back into the home’s structure. In this case study, we…
Over years of facing the relentless Cork weather, traditional flat roof felt can perish, bubble, and allow water to penetrate back into the home’s structure. In this case study, we highlight a complete multi-level flat roof transformation on an apartment block extension in Cork City, solving recurring leak issues with a premium, seamless waterproofing solution.
This multi-level flat roof had multiple complex details, including several soil/vent pipes, skylight domes (dome rooflights), and challenging wall junctions where it met the original pebbledash structure. Traditional felt was deteriorating under the damp valley air, allowing water to pool and bypass the seams. The goal was to provide a 100% seamless, durable barrier without the need to entirely strip and risk leaving the interior exposed to the unpredictable Cork rain during the work.
We cleared all loose debris and built-up grime, restoring the underlying deck to a sound, clean surface. Any compromised areas around the drains and penetrations were made secure.
The trickiest parts of any flat roof are the joints, skylight upstands, and pipe penetrations. We applied a dedicated reinforcement fleece and base coat around each of the soil vent pipes and skylights, embedding it to create a heavy-duty, flexible seal where movement is most common.
We applied our premium, seamless liquid-applied waterproofing membrane across the entire area (including a stark visual comparison in the progress image showing the newly coated light-grey protective membrane alongside the old, dark weathered sections). This creates an impenetrable, monolithic “skin” with absolutely no joints or seams that could fail over time.
To prevent any future water ingress from the perimeter, we ran the waterproofing system up the vertical brickwork and upstands, ensuring a complete water-tight connection below the pebble-dashed facade and coping stones.
The property now features a modern, weather-resistant, seamless flat roof built to withstand Atlantic rain and heavy winter frosts for decades. The light-grey finish also improves the thermal performance by reflecting sunlight and keeping the system from expanding or cracking (alligatoring) during summer.
Contact Hallmark Roofing Cork if you have any flat roofing problems in Cork city or county.
Hallmark Roofing provides trusted, affordable roofing services across Cork City and County. With over 15 years of experience, our fully trained and insured team delivers high-quality roof repairs, new roofs, flat roofing solutions, guttering, chimney work and more.
Copyright © 2026 Hallmark Roofing Cork. All Rights Reserved.
Web Design by Tradesman Marketing Experts