Serving Dublin & surrounding areas

Flat Roof Leak Repair Dublin

We trace and repair flat roof leaks on extensions, garages and commercial roofs across Dublin.

Leak tracing & targeted repairs

Same-day call-outs where possible

Clear written quote before follow-on work

Roof leak repair dublin by MJ roofing

Common Signs of a Flat Roof Leak

Flat roof leaks can be tricky to trace. Here’s what to look for:

Damp patches on ceilings below flat roof

Bubbling or peeling paint on internal walls

Damp along internal walls near flat roof edge

Musty smell in rooms below flat roof

Dripping near skylights or rooflights

Water stains at wall junctions or parapets

Water ingress after heavy rain

Visible cracks or splits in flat roof surface

Ponding water visible on roof surface

Moss or algae growth in low spots

Where Flat Roofs Usually Fail

Seams/Joints

Where flat roof sheets overlap — common weak point for water entry.

Edges/Drip Trim

Roof edges where membrane meets trim or flashing can split or separate.

Around Outlets/Drains

Water drainage points are vulnerable to seal failure and blockages.

Flashings at Walls/Parapets

Where flat roof meets upstand walls — high-risk area for leaks.

Rooflights/Skylights

Seals around roof windows can deteriorate, allowing water in. See our skylight repair services.

Cracks/Splits in Membrane

Felt or coating can crack due to age, weathering, or poor installation.

Blisters/Bubbling

Trapped moisture or air under membrane causes bubbles that can burst.

Poor Falls/Ponding Water

Inadequate drainage slope leads to standing water and premature failure.

What We Fix

Comprehensive flat roof leak repair services across Dublin properties.

Seam/Joint Leak Repairs

Seal and reinforce failed seams and overlaps.

Edge Detail Repairs

Fix edge trim, drip edges, and perimeter flashings.

Outlet/Drain Repairs & Reseals

Clear blockages and reseal drainage points.

Flashing Repairs at Walls/Parapets

Repair upstand flashings and wall junctions.

Patching Splits/Cracks

Patch damaged areas in felt or coating.

Temporary Waterproofing

Make-safe temporary repairs where possible.

Debris Removal

Clear debris to improve drainage and prevent ponding.

Photos Before/After on Request

Document repairs for your records.

How We Repair Flat Roof Leaks

When you call us for a flat roof leak repair in Dublin, we start with a thorough inspection of the roof surface, edges, flashings, outlets, and any rooflights or penetrations. Flat roof leaks can be deceptive — water often enters at one point but appears somewhere else entirely, particularly on shallow-pitched or flat surfaces where water travels along the underside of the membrane before dripping through.

We trace the water path to identify the true entry point, not just the visible stain. We check for ponding water (standing water that doesn’t drain), failed seams, cracked or split felt, deteriorated flashing at walls and parapets, blocked outlets, and any other signs of failure. If the leak is active and causing internal damage, we’ll carry out temporary make-safe waterproofing where possible to stop further water ingress while we prepare a quote for permanent repairs.

Repair options depend on the extent and location of the damage. For localised issues — a split seam, a failed outlet seal, or a small patch of damaged felt — we can often carry out targeted repairs without disturbing the entire roof. For more widespread problems — multiple leaks, aged membrane, poor falls causing chronic ponding, or extensive cracking — we may recommend flat roof renewal or refurbishment using modern systems like GRP fibreglass or liquid waterproofing. We’ll explain both options honestly so you can decide what’s right for your property.

All work is carried out with attention to detail, quality materials, and a tidy finish. We clean up properly, take photos for your records, and provide a clear written quote before proceeding with any follow-on work. You’re always in control — no surprises, no pressure. See our flat roofing solutions hub for more on flat roof options.

Active Flat Roof Leak?

Call us for urgent flat roof repairs in Dublin — same-day call-outs where possible.

Repair vs Renewal

When Repair Is Usually Enough

When Renewal May Be Better

We’ll inspect your flat roof and explain both options honestly so you can decide what’s right for your property.

Recent Flat Roof Leak Fixes

MJ Roofing Roof Repairs Dublin

Outlet Leak Repair — Dublin City

Blocked flat roof outlet causing ponding and leak. Cleared, resealed, and tested. Leak stopped, client satisfied.
MJ Roofing Dublin Roof Repair

Seam Repair on Extension — North Dublin

Failed seam on extension flat roof. Resealed and reinforced. Internal damp resolved, photos provided.
Professional roof repairs in Dublin

Parapet Flashing Repair — South Dublin

Water ingress at parapet wall junction. Flashing repaired and sealed. Leak traced and fixed properly.
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Service Areas

Areas We Cover

We provide flat roof leak repair services across Dublin and surrounding areas, including Dublin City, North Dublin, South Dublin, Swords, Malahide, Portmarnock, Lucan, Tallaght, Dundrum, Blackrock and nearby areas.

Frequently Asked Questions

How quickly can you attend a flat roof leak in Dublin?

We aim to respond as quickly as possible for flat roof leaks in Dublin, often within the same day for urgent issues causing active water ingress or internal damage. Response time depends on our current workload, your location, and weather conditions. If you have an active leak — particularly one affecting electrics, causing ceiling damage, or flooding internal spaces — call us directly and we’ll prioritise your call-out. For non-urgent leaks or older stains, we can usually attend within 24-48 hours. Where possible, we’ll carry out temporary make-safe waterproofing during the initial visit to stop further damage while we prepare a quote for permanent repairs. See our emergency roof repairs page for urgent call-outs.

Yes, in most cases. If the leak is localised — a failed seam, a damaged outlet, a split at the edge, or a small patch of deteriorated felt — we can often carry out targeted repairs without replacing the entire flat roof. This is usually the most cost-effective approach when the roof is generally in good condition and the damage is confined to a specific area. However, if the flat roof has multiple leaks, widespread cracking, chronic ponding water due to poor falls, or is at end of life (typically 20+ years for felt roofs), replacement or refurbishment may be the better long-term solution. We’ll inspect your flat roof honestly and explain both options — repair and renewal — so you can decide what’s right for your property and budget.
Ponding water — standing water that doesn’t drain — is caused by inadequate falls (insufficient slope) on the flat roof surface. Flat roofs should have a slight gradient (typically 1:80 or 1:40 minimum) to allow water to drain towards outlets or edges. When falls are insufficient, poor, or when the roof deck sags over time, water collects in low spots. This ponding accelerates flat roof deterioration because the constant water exposure breaks down the membrane, felt, or coating. It also increases the risk of leaks because even small defects in the ponding area allow water to seep through. Blocked outlets or debris buildup can also cause ponding. Fixing ponding issues may require improving drainage, clearing outlets, or in some cases, overlaying the roof with a system that builds in proper falls.
Yes, we repair leaks around rooflights and skylights on flat roofs. These are common leak points because the seals, flashings, and upstands around the rooflight can deteriorate or fail over time. Water can enter where the rooflight frame meets the flat roof membrane, particularly if the flashing is cracked, the sealant has perished, or the upstand detail was poorly installed. We inspect the rooflight surround, check the seals and flashings, and carry out repairs or resealing as needed. If the rooflight itself is damaged, cracked, or beyond repair, we can advise on replacement options. See our skylight installation & repair page for more on rooflight work.
Yes, always. After inspecting your flat roof and tracing the leak, we take photos showing the damage, the entry point, and any contributing factors like ponding water, failed seams, or deteriorated flashings. These photos are useful for your records, insurance claims, or landlord documentation. We then provide a clear written quote that explains the repair work needed, materials to be used, and the cost breakdown. If temporary make-safe work is carried out during the initial visit, we document that too. Everything is explained upfront before we proceed with permanent repairs — no hidden extras, no surprises. You’ll know exactly what you’re paying for and why.
It depends on the severity of the weather and the type of repair needed. Light rain or overcast conditions usually don’t prevent us from carrying out temporary make-safe waterproofing or minor repairs. However, heavy rain, high winds, or very cold temperatures can make some flat roof repairs unsafe or ineffective — particularly those involving adhesives, sealants, or coatings that require dry conditions to cure properly. If weather prevents permanent repairs, we’ll make the roof safe temporarily (tarpaulin, temporary waterproofing) and schedule the full repair for the next suitable weather window. We’ll always explain the limitations honestly and work with you to find the best approach. Safety and quality are priorities — we won’t rush repairs in conditions that compromise either.
Yes, we carry full public liability insurance for all roofing work, including flat roof leak repairs, outlet repairs, flashing work, and flat roof refurbishments. This protects your property and covers our team while working at height and on flat roof surfaces. Flat roof repairs require safe access, proper equipment, and working on potentially slippery or fragile surfaces — all of which we approach with health and safety procedures in place. You can ask to see our insurance documentation at any time. We’re experienced in repairing flat roofs on Dublin extensions, garages, and commercial properties, and we take professionalism and safety seriously on every job.
We repair most common flat roof systems found on Dublin properties, including traditional felt roofs (torch-on felt, three-layer felt), GRP fibreglass roofs, and liquid-coated roofs. We also repair EPDM rubber roofs where appropriate. The repair approach depends on the type of system, the age of the roof, and the extent of damage. Some systems — like felt — can be patched or resealed relatively easily. Others — like GRP — may require specialist repair techniques. We’ll inspect your flat roof, identify the system type, and explain the best repair options. If your flat roof is an unusual or specialised system, we’ll be honest about whether we can repair it or if a specialist contractor is needed.
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