Flat Roof
Repairs
Cavan
Leaking flat roof on your extension, garage or porch? We diagnose the exact cause, repair it properly and leave no mess behind. Fully insured, VAT registered, fast free quotes across Cavan and Meath.
What Flat Roof Repairs Actually Involves
Flat roofs are not truly flat. They sit at a very shallow pitch — typically 1:80 or so — to encourage drainage. That shallow angle, combined with an exposed membrane, means any failure in the waterproof layer lets water pool and sit rather than run off. The damage builds quickly once it starts.
Our flat roof repair service covers extensions, garages, porches, bay window roofs and outbuildings across Cavan, Navan, Ashbourne and County Meath. We work with all three main membrane types: traditional torch-on felt, GRP fibreglass and EPDM rubber. Work ranges from a targeted patch repair on a single split seam, through flashing replacement and upstand repairs, right up to a full strip-and-re-cover where the existing membrane has reached the end of its life.
If your flat roof is connected to pitched roof repairs — for example, a dormer or a rear extension butting up against the main roof slope — we can handle both on the same visit. We also repair the gutters and fascias that drain a flat roof, because a blocked outlet is just as destructive as a split membrane.
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Common Flat Roof Problems & Their Causes
Flat roofs fail in predictable ways. Knowing the cause determines the correct repair — a patch over the wrong problem will fail again within months.
Ponding Water
Water that sits for more than 48 hours after rain indicates inadequate falls or a blocked outlet. Over time, the standing water degrades the membrane and adds structural load to the deck. We re-cut drainage channels or fit additional outlets as required.
Split or Cracked Felt
Traditional three-layer felt has a lifespan of roughly 10–15 years. As it ages, the bitumen becomes brittle, especially on a south-facing roof baked by summer sun. Splits allow water straight through to the timber decking. We cut out the damaged section and weld in a new repair layer, or re-cover the whole surface if the damage is widespread.
Blistering Membrane
Blisters form when moisture or trapped air expands under the membrane in hot weather. A blister is not yet leaking, but the membrane is stretched thin and will eventually split. We cut, dry, and re-bond the blistered section before it becomes a water ingress point.
Failed Flashings
Flashings seal the joint where a flat roof meets a wall, parapet or chimney stack. Lead or code-5 aluminium flashing is bedded into a chase in the mortar. When the mortar fails or the flashing lifts, water tracks down the wall cavity. We re-point the chase, re-bed the flashing and lap the membrane correctly — the most common repair we carry out in Cavan.
Rotted Roof Deck
Once water reaches the plywood or OSB deck beneath the membrane, rot sets in. Soft, spongy patches underfoot are the tell-tale sign. We remove the membrane, replace the damaged board sections, allow everything to dry fully, and then re-cover with a modern membrane. Carrying out repairs while the deck is wet will cause the new surface to fail prematurely.
Upstand & Parapet Failures
The upstand is the vertical section of membrane that runs up a wall above the roof surface. If it is too short — under 150mm — or has separated from the wall, wind-driven rain gets behind it. We lap and bond the upstand to the correct height and dress it with lead cover flashing to prevent future movement.
The Repair Process, Step by Step
We follow the same sequence on every job — no cutting corners, no rushing the dry-out period, no painting over a problem.
Free Inspection & Diagnosis
We get on the roof and look at the membrane, flashings, outlets and deck. Where the leak is visible internally, we cross-reference the entry point with the roof layout above. We tell you exactly what we find — no vague estimates.
Clear Quote Before Any Work Starts
You receive a written quote itemising the repair scope: what is being removed, what is going back, and the membrane system being used. No surprises on the invoice.
Strip & Deck Inspection
We remove the existing membrane down to the deck. Any wet or rotten boards are replaced before the new surface goes down. Skipping this step is the single biggest cause of premature flat roof failure.
Falls Check & Outlet Clearance
We check the existing drainage falls and clear or reposition outlets. Where ponding was previously an issue, we discuss options for improving drainage before laying the new surface.
Membrane Installation
The new membrane is installed according to the manufacturer's specification — correct overlap, heat-welded seams or chemically bonded laps, upstands at the correct height, and all penetrations (pipes, vents, rooflights) fully detailed.
Flashings & Finishing
Lead or aluminium flashings are dressed to all abutments and pointed into mortar chases. Any affected gutters or fascias are checked before we leave. The site is left clean.
Final Check & Handover
We walk the roof with you, explain what was done and answer any questions. We confirm the repair in writing so you have a record for any future property transaction.
Membrane Systems Explained
Torch-On Felt
High-performance SBS-modified bitumen applied with a gas torch. Modern torch-on felt is far superior to the old three-layer cold-bonded systems. Good for standard repairs where the existing felt detail is being matched. Typically 15–20 year lifespan.
GRP Fibreglass
Glass-reinforced polyester laid as a fully seamless shell. Rigid, hard-wearing and compatible with roof terraces and areas with light foot traffic. Requires a smooth, dry, stable deck. Excellent lifespan of 25+ years when installed correctly.
EPDM Rubber
Ethylene propylene diene terpolymer — a single-ply rubber sheet bonded to the deck with contact adhesive. Highly flexible, so it copes well with minor deck movement and temperature swings common in Cavan winters. Lifespan of 30+ years with minimal maintenance.
What Affects the Cost of a Flat Roof Repair?
Flat roof repair costs vary considerably and we never quote a figure before we have seen the job. What we can tell you is the factors that drive the price — so you know what you are paying for and why.
For a rough sense of the range, see our guide on how much roof repairs cost in Ireland, which covers the main cost drivers across all roof types.
- Size of the roof area. Larger surfaces require more material and more labour time. We price by the square metre for re-covers.
- Extent of deck damage. If water has reached and rotted the plywood below the membrane, boarding replacement adds to the cost. We only discover the full picture once the old membrane is stripped.
- Membrane system chosen. GRP fibreglass and EPDM rubber materials cost more than torch-on felt, but their longer lifespans and lower maintenance requirements often make them better value over time.
- Number of penetrations and details. Each rooflight, pipe, vent or soil stack requires individual detailing. More penetrations mean more labour at those junctions.
- Access and height. Roofs on two-storey extensions or with restricted access may require scaffolding or a mobile tower, which adds to the overall cost.
- Repair vs re-cover. A targeted patch repair on a single problem area is considerably less expensive than stripping and re-covering the entire roof surface.
Your quote from Falcon Roofing will itemise every element so you can see exactly where the money goes. We do not charge call-out fees for the initial inspection.
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Honest Reasons to Choose Us
We are a local team based in Cavan. When we say fast response, we mean it — you are not waiting a week for a roofer to drive from Dublin. Here is what we actually deliver.
Fully Insured
Public liability and employer's liability insurance in place. You are protected throughout the job. Ask to see the certificate before we start — we are happy to provide it.
VAT Registered
All invoices are fully VAT compliant. You receive proper documentation — important for rental properties, building management and tax compliance.
Fast Response
We cover Cavan, Meath, Navan and Ashbourne and can usually inspect within days of your call. When a flat roof is actively leaking, speed matters — waiting weeks for a quote lets the damage spread into the ceiling and walls below.
Clear, Fixed Quotes
We quote in writing before any work starts. The price on the quote is the price on the invoice — no hidden extras, no vague estimates that balloon once we are on the roof.
For other roofing work alongside your flat roof, see our full roofing and building services or visit the Falcon Roofing and Building homepage to learn more about who we are.
Flat Roof Repairs Across Cavan & Meath
We carry out flat roof repairs across our full service area. Travel is included in your quote — no surprise call-out charges added later.
Based in Cavan, we regularly travel to Navan and Ashbourne for flat roof work. If you are unsure whether you are within our area, just call — we will tell you straight away. Our Navan roofing page and Ashbourne roofing page have more detail on the services we carry out in those areas.
Flat Roof Questions Answered
Real questions from homeowners in Cavan and Meath — answered directly, without padding.
How do I know if my flat roof needs repairing or replacing?
If the damage is limited to a single area — a split seam, a cracked flashing or a small blister — a targeted repair is usually sufficient. If the membrane has aged out, shows widespread cracking, or water has reached the decking underneath and caused rot, a full re-cover is more cost-effective long-term. A proper inspection will tell you which situation you are in before any money changes hands. See our guide on roof repair costs in Ireland for more context on what each option typically involves financially.
What causes a flat roof to leak in the first place?
The most common causes are failed or lifted flashings where the roof meets a wall or parapet; splits and blisters in an ageing felt membrane; blocked or undersized outlets causing standing water; damaged pointing around upstands; and UV degradation of the surface mineral finish. Cavan's wet climate and freeze-thaw winters accelerate all of these — water gets into a hairline crack, freezes, expands and opens the gap further. If you also have issues with the gutters draining away from the flat roof, our gutter repair service can sort that at the same time.
Is GRP fibreglass or EPDM rubber better for a flat roof in Ireland?
Both are durable, modern options well suited to the Irish climate. GRP (fibreglass) forms a rigid, seamless shell that handles foot traffic well and suits smaller roofs and roof terraces. EPDM rubber is highly flexible, excellent on larger spans, and copes well with the temperature swings common in Cavan — from hard frosts in January to warm summers. The right choice depends on the roof size, shape, any roof lights or penetrations, and your budget. We will explain the options clearly before any work begins so you can make an informed decision.
How long does a flat roof repair take?
A straightforward flashing repair or small membrane patch can be completed in a single day. A full flat roof re-cover on a typical single-storey extension — say 20 to 30 square metres — takes one to two days depending on the extent of any deck repairs needed. Larger garage or commercial flat roofs may take two to three days. We give you a realistic timeframe in the quote so you can plan accordingly. We keep disruption to a minimum and leave the site clean and weathertight before we go each evening.
Do you cover flat roof repairs in Navan and Ashbourne as well as Cavan?
Yes. Falcon Roofing and Building covers Cavan, Meath, Navan and Ashbourne for all flat roof repair work. Travel costs are factored into your quote from the outset so there are no surprise charges. If you are in Navan, see our Navan roofing page for more detail; if you are in Ashbourne, see our Ashbourne roofing page. Call or fill in the form below for a fast free quote.
Flat Roof Leaking? Get It Fixed Fast.
Free inspection, clear written quote, fully insured team. We cover Cavan, Navan, Ashbourne and County Meath. No call-out fee.
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