Porch Roof Flat Roof

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Stay Safe & Don't Worry About Exact Numbers! There is no need to climb your roof. Simply estimate the dimensions to your best knowledge. I will personally take precise measurements during a free site visit, and the final price will be calculated using the exact same transparent formula.

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15 Yrs System Warranty 25 Yrs Expected Lifespan
The highly recommended choice for long-term peace of mind. I will install a heavy-duty underlay followed by a premium charcoal mineral top sheet. Welding these two layers together creates a thick, impenetrable shield against the harsh British weather. This system is designed to last at least 15 years, keeping your garage bone-dry and secure.
Tecnatorch SBS Torch-On Mineral Felt Charcoal
Tecnatorch SBS Torch-On Mineral Felt Charcoal

Included in Price

Tecnatorch SBS Torch-On Plain Capsheet Sanded
Tecnatorch SBS Torch-On Plain Capsheet Sanded
Tecnatorch SBS

This SBS-modified sanded felt is the core component that upgrades your roof to a high-performance dual-layer system. It provides a robust, elasticated base that perfectly bonds with the final charcoal cap sheet for maximum strength. This foundation layer allows the roof to expand and contract safely during UK weather extremes, preventing cracks and leaks. Choosing this system ensures the highest level of durability and long-term peace of mind.

Included
Felt drip edge (4 sides Hardboard)
Felt drip edge (4 sides Hardboard)

Installing a hardboard trim around the entire roof perimeter to create sharp, rigid drip edges for the new felt. This solid backing allows the felt to be formed into a neat overhang, rather than a weak curve. It effectively directs rainwater away from the fascia boards and stops water from tracking back underneath the roof. This ensures a clean, professional finish and full perimeter protection.

Included
Bitumen Primer: Material Application
Bitumen Primer: Material Application
Cromar

Applying a bitumen primer is a crucial preparation step before installing the new waterproofing system. This liquid coating seals the existing substrate and locks in any remaining dust. Its main purpose is to create the perfect conditions for the first layer of felt to adhere flawlessly. This guarantees a strong, permanent bond between the treated surface and the felt.

Included
Ladder Access Work (Scaffolding Not Included)
Ladder Access Work (Scaffolding Not Included)

This service includes access using standard ladders or a hook ladder. Many repairs can be carried out efficiently without the need for scaffolding, saving both time and cost. However, safety is always our priority. If site conditions do not allow safe ladder use (e.g. limited space or difficult access), scaffolding may be required and is not included in this price.

Included
Felt drip edge (4 sides Hardboard)
Felt drip edge (4 sides Hardboard)

Installing a hardboard trim around the entire roof perimeter to create sharp, rigid drip edges for the new felt. This solid backing allows the felt to be formed into a neat overhang, rather than a weak curve. It effectively directs rainwater away from the fascia boards and stops water from tracking back underneath the roof. This ensures a clean, professional finish and full perimeter protection.

Included
Bitumen Primer: Material Application
Bitumen Primer: Material Application
Cromar

Applying a bitumen primer is a crucial preparation step before installing the new waterproofing system. This liquid coating seals the existing substrate and locks in any remaining dust. Its main purpose is to create the perfect conditions for the first layer of felt to adhere flawlessly. This guarantees a strong, permanent bond between the treated surface and the felt.

Included
Ladder Access Work (Scaffolding Not Included)
Ladder Access Work (Scaffolding Not Included)

This service includes access using standard ladders or a hook ladder. Many repairs can be carried out efficiently without the need for scaffolding, saving both time and cost. However, safety is always our priority. If site conditions do not allow safe ladder use (e.g. limited space or difficult access), scaffolding may be required and is not included in this price.

Included

Optional Add-ons

This service involves a complete restoration of the existing lead flashing. First, the surface is mechanically cleaned using a wire brush to remove oxidation and debris. We then apply Lead Patination Oil, which protects the metal from weathering and prevents white carbonate staining on your roof. Finally, the brickwork joint is cleaned and resealed using a high-quality specialist lead sealant (silicone) to ensure a long-lasting, watertight finish.

Installation of new Code 4 lead flashing (150mm) to create a secure, watertight seal where the roof meets the brickwork. We professionally fit the lead into the masonry joints and apply Lead Patination Oil to the surface. This protective coating prevents natural oxidation and stops white carbonate streaks from staining your new roof. The joints are finished with high-quality specialist lead sealant, which stays flexible and handles temperature changes better than standard silicone. This method ensures a long-lasting lifespan and reliable protection against the weather.

A surcharge for removing old protective stone chippings from the existing roofing felt. Years of weather exposure cause these stones to melt and bond into a solid crust with the underlying bitumen. Removing them requires intensive physical labour to chip and scrape the surface clean. This crucial step ensures the new roof adheres properly.

Replace weakened or failing garage roof joists to ensure the entire structure remains stable and secure. This is necessary when existing timbers are soft from rot, bowing under weight, or compromised by pests. We provide and install new, high-quality timber joists up to 4 metres long. Simply specify the number of joists required; the price is calculated per unit for a complete installation.

Essential when your roof deck is rotten or sagging. We strip all old felt and timber boards back to the bare joists, creating a clean base for reconstruction. Price includes all labour, professional skip hire delivered to your site, and licensed waste disposal fees. No hidden costs for rubbish clearance. Note: This covers removal only; please also add "New OSB Deck Installation" to your estimate to include the new structural boards.

We create a rock-solid foundation using premium 18mm OSB3 moisture-resistant boards, specifically engineered for structural use in the British climate (BS EN 300 standard). These high-performance boards offer superior strength and durability compared to standard chipboard, ensuring a perfectly flat and stable base for your new roof. Each sheet is precision-fitted and securely fastened to the joists to prevent future movement. Note: This service covers new material and installation only.

15 Yrs Warranty 25 Yrs Lifespan

Preparation and Vapour Barrier: A functional vapour barrier is the most critical step. It stops warm, moist indoor air from rising into the insulation, where it would otherwise condense on the colder upper layers of the roof and cause hidden moisture or rot. In many cases, your existing roofing felt can serve as a reliable vapour barrier if it is in good condition. Insulation Laying and Fixing: We install the 100mm insulation boards onto the prepared base. To maintain the integrity of the vapour barrier underneath, we secure the boards using specialized expanding roofing foam. Mechanical fixings are only used in extreme conditions, such as on very tall buildings or highly exposed coastal sites. Edge Reinforcement (Included in Price): Adding insulation raises the overall roof height by 100mm. Therefore, we install new structural timber rafters of the same thickness around the entire perimeter to reinforce the edges. These timbers and their installation are fully included in the price of this item. Fascia Board Adjustment (Not Included): Please note that because the roof profile is raised, new and deeper uPVC fascia boards are almost always required to aesthetically and functionally cover the new height. These boards are not included in this specific item and are quoted separately. Final Waterproofing: Once the insulation is secured, a new protective system is torch-applied directly on top. This consists of a heavy-duty underlay and a final mineral cap sheet that protects the roof from UV radiation.

A surcharge for removing old protective stone chippings from the existing roofing felt. Years of weather exposure cause these stones to melt and bond into a solid crust with the underlying bitumen. Removing them requires intensive physical labour to chip and scrape the surface clean. This crucial step ensures the new roof adheres properly.

Installation of new Code 4 lead flashing (150mm) to create a secure, watertight seal where the roof meets the brickwork. We professionally fit the lead into the masonry joints and apply Lead Patination Oil to the surface. This protective coating prevents natural oxidation and stops white carbonate streaks from staining your new roof. The joints are finished with high-quality specialist lead sealant, which stays flexible and handles temperature changes better than standard silicone. This method ensures a long-lasting lifespan and reliable protection against the weather.

This service involves a complete restoration of the existing lead flashing. First, the surface is mechanically cleaned using a wire brush to remove oxidation and debris. We then apply Lead Patination Oil, which protects the metal from weathering and prevents white carbonate staining on your roof. Finally, the brickwork joint is cleaned and resealed using a high-quality specialist lead sealant (silicone) to ensure a long-lasting, watertight finish.

Estimate Summary

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Porch Flat Roof Cost Calculator | Instant Quotes for Sussex Homeowners

Is your front porch suffering from a persistent drip or an unsightly, aged covering? The roof of your porch is the first thing guests see and a vital line of defence for your home’s entrance. My instant online calculator provides a fully itemised, transparent estimate for a professional porch roof replacement or repair across Brighton, Hove, Worthing, and Sussex. With 18 years of specialized experience, I ensure your porch is not only watertight but also enhances the curb appeal of your property.

Small Roof, High Technical Standards

Don’t let the small size fool you—porch roofs require precision. The most common failure point is the junction where the flat roof meets the main house wall. I utilise high-performance SBS-modified torch-on felt systems combined with expert leadwork. These rubberised membranes are designed to handle the variable UK weather, ensuring they remain flexible and crack-free even during the coldest winters and hottest summers.

Total Weather Protection & Insulation

Even a small porch can benefit from modern roofing standards. My approach focuses on structural integrity and longevity:

  • Lead Flashing Excellence: We install or refurbish Code 4 lead flashing at the wall abutment to create a permanent, watertight seal that prevents water from tracking into your hallway.
  • Structural Foundation: If your porch deck is sagging, I replace it with 18mm OSB3 moisture-resistant structural boards to ensure a perfectly flat, solid surface.
  • Thermal Comfort (Optional): Adding 100mm insulation to your porch roof can prevent heat loss from your front door area and eliminate condensation issues above your entrance.

Curb Appeal with Full Transparency

Choosing my services means choosing total peace of mind. Every porch project includes access to a Secure Client Portal, allowing you to manage everything from your phone:

  • Live Photo Logs: I document the prep work, the leadwork, and the final cap sheet, providing visual proof of a job done right.
  • Instant Project Tracking: Follow the progress of your porch installation through a clear, visual timeline.
  • Digital Records: Keep your itemised estimates, receipts, and long-term warranties safe and accessible in one place.

Ready to fix your porch roof? Enter the dimensions in the calculator above and choose your system. I will personally confirm all details during a free site visit to ensure your final quote is 100% accurate.