Flat Roof Specialists — North London
Flat Roof Installation
Built to Last Decades,
Not Just Years
Stop wasting money on temporary fixes. We install flat roofing systems that eliminate leaks, reduce energy bills, and add measurable value to your property — backed by a written guarantee.
★ 5.0 Google Rating · 2,000+ roofs completed · Same-day estimates available
What Is a Flat Roof and When Do You Need One?
A flat roof is a roofing system with a pitch of less than 10 degrees, commonly found on extensions, garages, dormers, and commercial buildings across London. Unlike pitched roofs, flat roofs require specialist materials and installation techniques to prevent water pooling and ensure long-term performance.
You might need a new flat roof if your existing one is leaking, sagging, showing signs of blistering, or has simply reached the end of its lifespan. Many flat roofs installed in the 1970s and 1980s used basic felt systems that were never designed to last more than 10–15 years. If yours is older than that, it's almost certainly costing you money in heat loss and water damage.
At AC Roofing & Carpentry Ltd, we install modern flat roofing systems including EPDM rubber, GRP fibreglass, and high-performance felt. Each system is selected based on your property type, budget, and expected lifespan — not what's cheapest for us to install.
Whether it's a residential extension in Islington, a garage in Hackney, or a commercial unit in Camden, we deliver flat roof installations that perform for 25 years or more. Every installation includes proper drainage design, insulation upgrades where applicable, and a written workmanship guarantee.
What Happens When You Ignore a Failing Flat Roof?
A flat roof that's past its prime doesn't just leak — it causes a chain reaction of expensive problems. Water ingress penetrates the deck boards, rots the timber joists beneath, and creates damp conditions that travel through ceilings and walls. Within months, you're dealing with structural damage, mould growth, and compromised insulation.
Many homeowners try to extend a failing flat roof's life with patches and sealants. These temporary fixes rarely last more than one winter. They also hide the real damage happening underneath, meaning by the time you address the root cause, the repair bill has doubled or tripled.
Ignored flat roof issues also drive up heating costs. A poorly insulated or water-damaged flat roof can account for up to 25% of heat loss in a property. That's hundreds of pounds wasted every year on energy bills alone.
The longer you wait, the more it costs. A simple re-cover that might cost £1,500 today could become a full deck replacement at £4,000+ if the timber rots through. Acting early saves money, protects your property, and eliminates the stress of emergency repairs.
How We Work
Our Proven 5-Step Flat Roof Process
Survey & Assessment
We inspect the existing roof, measure up, and assess the deck condition — no guesswork.
System Selection
We recommend the best material (EPDM, GRP, or felt) based on your property and budget.
Deck Preparation
We strip the old roof, replace any damaged timber, and prepare a clean, solid deck.
Installation
Your new flat roof is installed with proper falls, sealed edges, and correct drainage.
Final Check & Guarantee
We water-test, photograph the finished work, and issue your written guarantee.
Why It Matters
Why a New Flat Roof Pays for Itself
25+ Year Lifespan
Modern EPDM and GRP systems last two to three times longer than traditional felt.
Zero Leak Risk
Properly installed flat roofs with seamless membranes eliminate water ingress entirely.
Lower Energy Bills
New insulation boards fitted as standard reduce heat loss by up to 25%.
Added Property Value
A certified flat roof installation adds demonstrable value when selling or remortgaging.
Minimal Disruption
Most residential flat roofs are completed in 1–2 days with no interior access needed.
Written Guarantee
Every job comes with a written workmanship guarantee — your investment is protected.
Flat Roofing Systems: A Complete Technical Guide
EPDM Rubber Roofing
EPDM (Ethylene Propylene Diene Monomer) is a synthetic rubber membrane that has become the gold standard for residential flat roofing. It's supplied in large single sheets, which means fewer joints and virtually zero leak points. EPDM is UV resistant, handles temperature extremes from -40°C to +120°C, and has a proven track record of lasting 40+ years in real-world conditions. We use Firestone RubberCover and ClassicBond systems, both of which carry manufacturer guarantees of 20 years. EPDM is ideal for extensions, garages, dormers, and any flat roof up to around 60m².
GRP Fibreglass Roofing
GRP (Glass Reinforced Plastic) creates a completely seamless, rigid finish that's walked-on durable. It's applied as a liquid resin over glass fibre matting, curing to form a single waterproof shell with no joints or seams. GRP is the preferred choice for balconies, walkways, and any flat roof that needs to withstand foot traffic. It's also highly resistant to impact, chemicals, and moss growth. Our GRP installations include proper trim details, drip edges, and a topcoat that can be colour-matched to your property. Expected lifespan is 30–40 years with zero maintenance required.
High-Performance Felt Roofing
Modern torch-on felt systems are a significant step up from the old pour-and-roll method. They use modified bitumen membranes with polyester or fibreglass reinforcement, applied with a gas torch for a heat-welded bond. While felt doesn't last as long as EPDM or GRP (typically 15–20 years), it's a cost-effective option for budget-conscious projects. We recommend three-layer felt systems with a mineral cap sheet for maximum durability. Felt remains a solid choice for garages, sheds, and outbuildings where the budget doesn't stretch to rubber or fibreglass.
Residential vs Commercial Flat Roofs
Residential and commercial flat roofs share the same physics but differ in scale, access requirements, and material specification. Commercial flat roofs are typically larger, may need to support plant equipment or foot traffic, and often require single-ply membrane systems like TPO or PVC for larger spans. Residential flat roofs are generally smaller and more suited to EPDM or GRP. We handle both — from a single garage roof in Finsbury Park to multi-unit commercial buildings in Hackney. Our team is experienced with the specific challenges of each, including fire rating requirements, building regulations compliance, and access logistics.
Insulation and Building Regulations
Under current building regulations, any flat roof replacement must meet minimum thermal performance standards (U-value of 0.18 W/m²K or better). This means fitting rigid insulation boards — typically PIR (Polyisocyanurate) — either above or below the deck. Warm deck construction (insulation on top) is the industry standard because it keeps the deck warm, prevents condensation, and maximises the roof's lifespan. We handle all building control notifications and ensure every installation is fully compliant. Upgrading your insulation isn't just a legal requirement — it makes a noticeable difference to your heating bills from day one.
Common Questions
Frequently Asked Questions
Protect Your Property Today
Speak to our team for honest advice and a no-obligation estimate. Most quotes delivered within 24 hours.