How to Estimate a Roofing Job — Pricing Guide for Roofers

Estimating roofing jobs accurately is one of the most important skills a roofer can develop. Roofing work involves significant material costs, labour, scaffolding, and waste disposal, plus the ever-present risk of discovering hidden problems once you strip the existing covering. Get your estimate wrong and you could be working at a loss on a job that takes longer than expected with materials that cost more than you quoted.

This guide walks you through a systematic approach to estimating roofing jobs in the UK. Whether you are quoting for a simple tile replacement, a full re-roof, or a flat roof conversion, the principles are the same: measure accurately, price materials carefully, calculate your labour realistically, and always allow for contingency.

Step 1: Survey the Roof

Every accurate estimate starts with a thorough survey. You need to understand exactly what you are dealing with before you can put a price on the job. Never quote from photos alone unless the job is truly straightforward like replacing a handful of slipped tiles.

What to Assess During the Survey

• Roof type and pitch. Is it a pitched roof with tiles or slate, a flat roof, or a combination? What is the approximate pitch angle? Steeper roofs take longer to work on and may require additional safety measures.
• Current condition. What state is the existing covering in? Are there visible signs of damage, sagging, or water ingress? Can you see any issues from inside the loft space?
• Roof furniture. Count the number of vent tiles, ridge tiles, hip tiles, valleys, and any other features that will need replacing or working around. Note any roof windows, satellite dishes, or solar panels that will need removing and refitting.
• Access. How easy is it to get scaffolding to the property? Are there narrow access routes, overhead cables, conservatories, or other obstacles? Difficult access increases scaffolding costs and can slow down the work.
• Loft condition. If you can get into the loft, check the condition of the rafters, purlins, and battens. Look for signs of rot, woodworm, or previous bodge repairs. These are the hidden costs that catch roofers out if they do not look.
• Neighbouring properties. For terraced or semi-detached houses, consider the party wall and how your work interfaces with the neighbouring roof. You may need to build up a lead flashing against their wall or tie in to their ridge.

Take Photographs

Photograph everything during the survey. The roof from multiple angles, close-ups of any damage or problem areas, the loft space, the access route, and any features that will affect the work. These photos are invaluable when you sit down to price the job later, and they also serve as a record of the roof's condition before you start work.

Step 2: Measure the Roof

Accurate measurement is the foundation of an accurate estimate. You need to know the total roof area to calculate material quantities, and you need to know the linear metres of ridges, hips, valleys, and verges to price those elements.

Calculating Roof Area

For a simple gable-to-gable roof, measure the length and width of the building at ground level. The plan area (length times width) then needs to be adjusted for the roof pitch. Multiply the plan area by the pitch factor to get the actual sloped area:

• 15-degree pitch: multiply by 1.04
• 20-degree pitch: multiply by 1.06
• 25-degree pitch: multiply by 1.10
• 30-degree pitch: multiply by 1.15
• 35-degree pitch: multiply by 1.22
• 40-degree pitch: multiply by 1.31
• 45-degree pitch: multiply by 1.41

For hipped roofs, dormer windows, and complex shapes, break the roof into simple geometric shapes, calculate each one separately, and add them together. It takes longer, but it gives you an accurate total area.

Always add a waste allowance on top of your calculated area — ten per cent for straightforward roofs, fifteen per cent for complex roofs with lots of cutting around hips, valleys, and dormers.

Measuring Linear Features

Measure the total length of ridges, hip ridges, valleys, verges, and eaves. These determine how many ridge tiles, hip tiles, valley troughs, verge clips, and eaves courses you need. Do not forget to include any abutments where the roof meets a wall, as these will need lead flashings.

Step 3: Calculate Material Costs

Materials typically account for thirty to fifty per cent of the total cost of a roofing job, depending on the specification. Price everything from your merchants before you quote — do not rely on memory or last month's prices.

Main Roofing Materials

The main material categories to price for a typical re-roof include:

• Tiles or slates. Concrete interlocking tiles are the most economical at around fifty to seventy pence per tile. Plain clay tiles are more expensive at around one pound to one pound fifty each. Natural slate varies hugely — from two to three pounds per slate for Spanish slate up to six pounds or more for Welsh slate.
• Underlay (breathable membrane). Budget around one pound fifty to three pounds per square metre depending on the quality. Always use a breathable membrane on new work.
• Battens. Roofing battens (25mm x 50mm treated softwood) cost around forty to sixty pence per linear metre. Calculate the number of batten courses based on the tile gauge (the distance between battens, determined by the tile you are using).
• Ridge and hip tiles. Concrete ridge tiles are around three to five pounds each. Clay ridge tiles are five to ten pounds each. Dry ridge systems cost more upfront but are faster to install and increasingly preferred by customers.
• Lead flashing. Code 4 lead sheet costs around twenty to thirty pounds per linear metre. You will need it for abutments, valleys (unless using GRP valleys), and chimney flashings.
• Fixings. Nails, clips, tile clips for high-wind zones, and mortar or dry fix components all need to be priced. These are relatively small costs individually but add up across a full roof.
• Insulation. If the job includes upgrading the insulation to meet current Building Regulations, price this separately. Mineral wool insulation for a loft costs around five to eight pounds per square metre at the required thickness.

Step 4: Calculate Labour Costs

Labour is the other major component of your estimate. You need to work out how many person-days the job will take and multiply by your labour rate.

Typical Production Rates

Production rates vary depending on the roofer's experience, the roof complexity, weather conditions, and access. As a rough guide for a two-person roofing team:

• Strip existing tiles and battens: thirty to forty square metres per day
• Batten and felt (underlay): forty to sixty square metres per day
• Tile (interlocking concrete): thirty to forty square metres per day
• Tile (plain tiles or natural slate): fifteen to twenty-five square metres per day
• Ridge tiles (mortar bedded): fifteen to twenty metres per day
• Ridge tiles (dry ridge system): twenty to thirty metres per day
• Lead work: varies hugely depending on complexity

For a full re-roof of a typical three-bedroom semi-detached house (approximately sixty to seventy square metres of roof area), budget for five to eight working days for a two-person team, depending on the tile type and complexity.

Your Labour Rate

Your daily labour rate should cover your wages, overheads, and profit. For a detailed breakdown of how to calculate this, see our guide on how to calculate labour costs for construction jobs. In 2026, roofers in the UK typically charge between one hundred and seventy and two hundred and fifty pounds per day per person, depending on location and experience.

Step 5: Add Scaffolding and Ancillary Costs

Scaffolding is a significant cost on any roofing job, and it is the one that new roofers most commonly underestimate.

Scaffolding

For a standard two-storey semi-detached house, budget six hundred to one thousand two hundred pounds for a basic scaffold to one elevation. A full perimeter scaffold for a detached property could cost one thousand five hundred to three thousand pounds or more. Get a firm quote from your scaffolding company before you price the job — do not guess.

Remember to factor in the hire period. If the scaffold needs to stay up longer than the standard hire period (typically six to eight weeks), additional weekly charges apply.

Skip Hire and Waste Disposal

Old tiles, battens, felt, and any other waste need disposing of. A standard eight-yard skip costs two hundred to four hundred pounds depending on your area. For a full re-roof, you may need two skips. Alternatively, if you have access to a trade waste facility, you can dispose of materials more cheaply by taking them yourself — but factor in the time and fuel cost.

Other Costs

Do not forget to include any other costs specific to the job: tile vent installation, satellite dish refitting, chimney repairs, gutter replacement, and any structural timber repairs you can see are needed from your survey.

Step 6: Apply Contingency

Roofing is one of those trades where you almost always find problems you could not see until the old covering comes off. Rotten rafters, damaged purlins, failed underlay, wet insulation, and bodged previous repairs are common discoveries. You need to protect yourself against these unknowns.

A contingency of ten to fifteen per cent of your total price is standard for roofing work. For older properties — anything pre-1960, and especially Victorian and Edwardian houses — lean towards fifteen or even twenty per cent. The state of the timber underneath is an unknown until you strip the roof, and timber repairs can add significant cost.

How you present the contingency to the customer is important. Some roofers build it into their price silently. Others show it as a separate line item with a note explaining that it covers any unforeseen structural repairs. The latter approach is more transparent and avoids the difficult conversation of asking for more money mid-job if problems are found.

Common Roofing Job Prices in the UK (2026)

To give you a benchmark for your own estimates, here are typical price ranges for common roofing jobs in the UK. These include labour, materials, scaffolding, and waste disposal:

• Full re-roof (3-bed semi, concrete tiles): five thousand to seven thousand pounds
• Full re-roof (3-bed semi, natural slate): seven thousand to twelve thousand pounds
• Full re-roof (3-bed detached, concrete tiles): seven thousand to ten thousand pounds
• Ridge tile replacement (mortar to dry ridge): five hundred to one thousand two hundred pounds
• Valley gutter replacement: four hundred to eight hundred pounds per valley
• Flat roof replacement (typical garage, GRP): one thousand two hundred to two thousand five hundred pounds
• Flat roof replacement (typical extension, GRP): two thousand to four thousand pounds
• Chimney re-pointing and re-flashing: four hundred to one thousand pounds
• Tile repairs (replacing broken or slipped tiles): one hundred and fifty to four hundred pounds

These figures vary by region, with London and the South East typically twenty to thirty per cent higher than the national average.

Presenting Your Roofing Estimate

How you present your estimate to the customer can be the difference between winning and losing the job. A professional, detailed proposal builds confidence and justifies your price — even if you are not the cheapest.

Break down your estimate into clear sections: stripping and disposal, timber repairs if applicable, materials, installation, scaffolding, and any additional works. Include a description of the work at each stage, the materials you will use, and any guarantees you offer.

For roofing work in particular, customers appreciate seeing the specification — the exact tile or slate type, the underlay brand, whether you are using a dry ridge system, and the grade of lead for flashings. This detail demonstrates your expertise and makes it harder for competitors to undercut you with a vague quote that might use cheaper materials.

Tools like QuoteSmith can help you present roofing estimates professionally. Enter your line items and the AI generates a complete branded proposal with scope of work, timeline, and terms — ready to send to the customer within minutes of completing your survey.