Flat Roof Repair Specialists | Commercial & Residential

Specialist flat roof repair for commercial buildings and homes across London, the South East and South West

A flat roof repair done properly can extend the life of your roof. Done badly, it will buy you a bigger bill in six months. A small split lets in a trickle, the insulation soaks it up out of sight, and by the time you see a stain on the ceiling, the timber underneath is already on borrowed time.

Whether you manage a commercial site that cannot afford downtime, run a contracting project that needs a defect putting right, or own a home with a leak above the kitchen, the answer is the same. You need the cause found and fixed properly, not painted over.

Proactive Flat Roofing fixes flat roofs all day, every day. We are a dedicated flat roofing specialist, not a general roofer who takes the odd flat job. That focus is the difference between a flat roof repair that lasts and one that fails the next time the wind turns.

Commercial Flat Roof Repairs

A leak in a commercial building is never just a leak. It is stock at risk, staff working around buckets, tenants asking questions and a facilities budget under pressure. You need a contractor who turns up when they say they will, works around your operation, and gives you a paper trail you can hand to your insurer or your client without having to chase it.

We work with facilities managers, building owners and main contractors on commercial flat roofing repairs across offices, industrial units, retail premises, schools, healthcare buildings and mixed-use developments. We are TrustMark, CHAS and NFRC accredited, and we hold approved contractor status with Sika Sarnafil, Triflex and IKO, so the manufacturer warranties on your existing system stay valid when we work on it.

What you get from commercial flat roof repair with us

Expert Roof Surveys

A trained surveyor on site, not a salesperson. They inspect the roof, identify the failure poi nt and document everything with photos and video before any quote is written.

Flexible Repair Scheduling

Repairs scheduled around your operation. Out of hours and weekend work available on request, so trading and tenants are not disrupted.

Fully Compliant & Insured

Full RAMS, public liability cover to £10 million and the digital trail your H&S, insurer and client will want to see.

Compatible Repair Systems

Compatible repair systems for Sarnafil, Triflex, IKO, EPDM, mineral felt, asphalt and built up systems, so we work with what is already there rather than ripping it out.

Detailed Repair Reports

A clear written report after the repair, showing what was wrong, what we did and what to keep an eye on next.

Working with main contractors

If you are a main contractor and need a flat roofing specialist to put a defect right on a handover, a snag on a finished project or a reactive repair on a building you manage, we are set up to work as your subcontractor. We carry the accreditations and insurance documentation your principal contractor will ask for and we can mobilise inside the response windows most commercial clients work to.

Residential Flat Roof Repairs

If you have spotted a stain on the ceiling, a damp patch on the wall or water coming in around a skylight, you want someone to take a proper look and tell you the truth. Is it a flat roof repair, or has the roof had its day? You should not have to guess, and you should not be pushed into a full replacement when a targeted repair will do the job.

We repair flat roofs on extensions, dormers, garages, porches, bays, balconies and outbuildings across London, Berkshire, Surrey, Buckinghamshire and Hertfordshire. Every repair starts with a free 10 point flat roof condition survey worth £250, so you know exactly what the problem is and what your options are before you spend anything.

Common flat roof problems we put right

Splits and cracks in the waterproofing layer caused by years of building movement and UV.
Failed upstand and wall flashings where the roof meets a wall, parapet or tiled area.
Blistering on mineral felt roofs where moisture has worked under the top layer.
Leaks around skylights, soil pipes, vents and other roof penetrations.
Ponding water caused by deflection in the joists or blocked outlets.
Hidden interstitial condensation rotting the deck from underneath.

Honest advice on whether it is worth repairing

A repair is the right answer when the deck is sound, the failure is localised and the rest of the roof has life left in it. If the deck is rotten, the insulation is saturated or the system has reached the end of its design life, a repair is a sticking plaster on a problem that will keep coming back.

In those cases, you are looking at a full flat roof replacement instead. We will tell you which one you are looking at, in plain English, and give you the figures for both so you can decide.

How Our Flat Roof Repair Process Works

Whether it is a commercial site or a home, the process is the same. We take the guesswork out of it.

Get in touch

Phone or online enquiry. You tell us what you have spotted, where the building is and how urgent it is. We confirm whether it sounds like a repair job or whether you need our emergency callout service.

Free survey

Free flat roof survey on site. A trained surveyor inspects the roof inside and out, looks for the root cause rather than the symptom, and records everything on photo and video.

Quote & Report

Written report and itemised quote. You get a plain English condition report, a costed action plan and a clear recommendation. No pressure on the day, no salesman in your living room.

Repair Team

Repair carried out by our own qualified installers. We do not subcontract the work to a third party we have never met. The team that quotes is the team that fixes.

Sign-off and guarantee

Sign off, photographic record and guarantee. You get the digital paper trail of what was done and a guarantee on the repair work.

Why Property Owners and Contractors Choose Us For Flat Roof Repairs

Flat roof repair sounds simple. It is not. Most failures are not where the leak shows up inside, so anyone who turns up, slaps mastic on the wet patch and leaves is going to be back six months later. Here is what you get from us instead.

Dedicated flat roofing focus

Flat roofs are all we do. Every surveyor, every installer and every quality control manager on our team has spent their career on flat systems, which means they spot the things a general roofer walks past.

Root cause identification

We find the actual point of failure, not just the wet spot on the ceiling. Water travels along joists and battens before it shows up inside, so the leak is rarely where you think it is. We use electronic leak detection where it is warranted to pinpoint it accurately.

The Vanguard digital trail

Every job is documented with photos, video and a written report uploaded to a cloud based job folder. You get the evidence you need for your records, your insurer or your client without having to ask for it.

Manufacturer-approved installer

Approved contractor status with Sika Sarnafil, Triflex and IKO means we can repair these systems without invalidating the original warranty, which matters when the roof is still inside its guarantee period.

Qualified, insured and accredited team

TrustMark, CHAS and NFRC accredited, fully insured and trained in line with current building regulations. Everyone on your roof is a professional, not a passing labourer.

Response Times and Emergency Cover

For scheduled flat roof repairs we usually get a surveyor to site within a few working days, often sooner depending on location and the time of year. If water is actively coming in and you cannot wait for a survey, our emergency flat roof repair team aims to reach your property within a few hours of your call to stop the ingress and protect your building. Severe leaks on occupied or commercial buildings are prioritised first.

If it is an emergency right now, call 01753 303775 and we’ll do our best to help you fast.

Areas We Cover For Flat Roof Repair

Our head office is in Windsor, with teams covering London, the South East and South West. The towns below are within easy reach of our core operating area.

London →

Covering North London, South London, Central London and all surrounding areas.

Berkshire and Royal Borough→

Windsor, Slough, Maidenhead, Bracknell, Reading, Ascot, Sunningdale, Virginia Water, Sandhurst and Crowthorne.

Surrey→

Staines upon Thames, Egham, Chertsey, Weybridge, Woking, Camberley, Farnborough, Fleet, Farnham, Guildford, Leatherhead, Epsom, Esher and Walton on Thames.

Greater London→

Kingston upon Thames, Richmond upon Thames, Twickenham, Hounslow, Hayes, Southall, Uxbridge, Ealing, Chiswick, Harrow and Wembley.

Buckinghamshire→

High Wycombe, Beaconsfield, Gerrards Cross, Amersham, Chesham, Marlow and Henley on Thames.

Hertfordshire→

Watford, Hemel Hempstead and St Albans.

We also work further afield on large commercial projects. If you are outside the listed areas, call us anyway and we will give you a straight answer on whether we can help.

Accreditations & Awards

Google Reviews

    
 
 
      Posted on Google  
   
   Ben Inshaw 
 8 September 2026
 
 
 Trustindex verifies that the original source of the review is Google. Excellent from start to finish – highly recommended

I recently had a complete replacement of a large L-shaped flat roof, including multiple skylights, parapet walls and a number of other complexities. Having previously had the roof repaired twice by other companies and still experienced leaks, I decided enough was enough and wanted the whole roof stripped back and replaced by a reputable company. I’m so glad I found Pro Active Flat Roofing.

I was massively impressed with the whole process from beginning to end. Trish was fantastic from the initial booking of the survey, keeping me regularly updated throughout. Steven carried out the initial survey and was incredibly thorough, talking me through everything and patiently answering my many questions. The quote came through quickly and was detailed, which gave me a lot of confidence in the company.

Damian and Steven then worked with me on value engineering to get the project within my budget, without compromising on the quality of the solution. The whole team was also incredibly understanding when I unexpectedly needed to delay the project by a month.

The operations and logistics were equally impressive. Becky and the team kept everything organised, with the scaffolding, skips and roofing team all arriving exactly when they were supposed to. I received regular updates throughout the project, including daily photographs, and any queries I raised were dealt with quickly and effectively.

The team on the ground were brilliant. They were polite, professional, hardworking and clearly took a huge amount of pride in their work. They were real perfectionists and kept me updated throughout, including flagging any potential issues and discussing them with me before proceeding.

The quality of the finished roof is excellent. It looks really smart and, most importantly, we’ve since had some torrential rain and it finally doesn’t leak! After years of dealing with problems, that is a huge relief.

They also went above and beyond by sorting out an issue that was outside the scope of the project while I was away on holiday, which I was incredibly grateful for.

I would have absolutely no hesitation in recommending Pro Active Flat Roofing. I’ve come to realise that you really do get what you pay for. Having previously tried to save money on cheaper repairs and ultimately paid twice, I only wish I had found Pro Active sooner.

A fantastic company, an excellent team and a first-class job. Highly recommended.
  
 
     Posted on Google  
   
   Alan Brown 
 11 August 2026
 
 
 Trustindex verifies that the original source of the review is Google. I engaged Proactive to replace a flat roof for me after being expensively let down mid-job by another 'firm'.  To say that Proactive are highly professional would be to understate the matter - they are simply excellent.  An initial survey, followed by a technical survey led to the production of the time and materials schedule and all associated documentation.  All costs were itemised up-front and a price for the whole job agreed.  I had my own (attractive and intelligent) project manager allocated and she kept things on track and kept me informed.  Everything was properly co-ordinated, including materials delivery, skips and scaffolding - thanks, Becky.  The guys who did the work, Jake and Rocco, were first-rate and fun to have around as well as working like beavers on some of the hottest days of the year.

Once the job was done it was re-inspected by the relevant managers for any snagging issues before being signed off.  The guarantee is first-rate, and I have a client folder with dozens of photos showing the work progression at the end of each day.

Overall, I could not be happier with this.  Well done, PRF.
  
 
     Posted on Google  
   
   james graham stones 
 2 August 2026
 
 
 Trustindex verifies that the original source of the review is Google. Having been let down badly with poor workmanship.
I contacted Proactive Flat Roofing

After a very thorough survey of my roof by Mr Stephen Day, it was decided that the only option I had was to get the roof redone.

After getting another report from an independent surveyor who also condemned the roof as not fit for purpose.

I accepted the very concise written quote from Proactive Flat Roofing.I also received a very good guide booklet explaining  in detail  their product and their guidance to getting your roof done.

From the first site visit by Mr Stephen Day and then to the great communicational and organisational skills of the support team
Becky,Cloe,Yvonne,Charlotte,and Carla.
To the Skill and Professionalism of Dave the Roofing Technician.
I genuinely believe that I could not have contracted a more dedicated to customer satisfaction driven team of people.

If you are getting your flat roof done, do not go down the route I did by NOT checking the roofing businesses certification and accreditation certificates.
To get a "Proper Job" done
Think about giving PROACTIVE FLAT ROOFING A CALL
  
 
     Posted on Google  
   
   Georgina Cairns 
 2 June 2026
 
 
 Trustindex verifies that the original source of the review is Google. The team are highly professional. Paull helped us sort a roof on a house we had recently purchased that had some major construction flaws. Communication from the start was outstanding. Every member of staff we dealt with were very knowledgable and answered all our questions. Would certainly recommend, quality work.
  
 
     Posted on Google  
   
   Rich Jamieson 
 1 September 2025
 
 
 Trustindex verifies that the original source of the review is Google. A very professional organisation that attended site at agreed times to investigate our fault and came up with the required solution. The operatives were polite and friendly and kept us constantly informed of their progress. They kept disruption to a minimum and tidied up after them selves. A pleasure to deal with and would highly recommend.
  
 
     Posted on Google  
   
   Stuart Davis 
 12 June 2025
 
 
 Trustindex verifies that the original source of the review is Google. Highly organised, process-driven company. Clear communication & likeable site-team!
Product looks good so hopefully it’ll be as good as I’m lead to believe it will be! 🤞
  
 
     Posted on Google  
   
   Nancy Harris 
 12 June 2025
 
 
 Trustindex verifies that the original source of the review is Google. Proactive Flat Roofing fixed a major roof leaking problem. Their product and professional services far outweighed other companies I researched. Camaron and Ryan worked tirelessly to complete the job and I am highly satisfied with the outcome.
  
 
     Posted on Google  
   
   peter monk 
 20 May 2025
 
 
 Trustindex verifies that the original source of the review is Google. Proactive Flat Roofing undertook a roof refurbishment project that I was overseeing in Battersea.  They were extremely professional, co-operative and adaptable (we had a few obstacles to overcome due to difficult tenants) and their workmanship was excellent.  Overall very pleased and wouldn't hesitate to recommend them on any future suitable projects
  
 
     Posted on Google  
   
   Fiona Harrison 
 23 March 2025
 
 
 Trustindex verifies that the original source of the review is Google. Professional, efficient, polite, reliable.  Excellent service and finally my flat roof isn't leaking!
  
 
     Posted on Google  
   
   kelly 
 17 October 2024
 
 
 Trustindex verifies that the original source of the review is Google. Alex Jake and Camaron did a brilliant job and kept me well informed when things was going to happen or adjust when needed too, they was all very polite and professional people 😊 thank you again guys
  
 
 
  
 
 
   Verified by Trustindex  Trustindex verified badge is the Universal Symbol of Trust. Only the greatest companies can get the verified badge who has a review score above 4.5, based on customer reviews over the past 12 months. Read more

Frequently Asked Questions

How do I know if my flat roof needs repair or full replacement?

The only way to really get a reliable answer is a survey. Our free survey tells you whether your roof can be repaired or needs to be replaced and gives you quotes for any recommended works. You can book a free survey here.

How long does a flat roof repair take?

Most localised flat roof repairs are completed in 1-2 days. Larger commercial repairs involving multiple defect areas, flashings or upstands will take longer. We give you a clear timeframe in the quote so you can plan around it.

Do you guarantee your flat roof repairs?

Yes. We guarantee our repair workmanship and we are honest about what a repair guarantee can and cannot cover. A repair on a roof at the end of its life is not the same as a guarantee on a full new system, and we will tell you which you are buying.

Can you repair my existing roofing system without invalidating its warranty?

In most cases yes. We are approved contractors for Sika Sarnafil, Triflex and IKO, and we work with EPDM, mineral felt, asphalt and built up systems. If your roof is still inside its manufacturer warranty, tell us when you call and we will make sure the repair is carried out using compatible materials by an approved installer.

Do you work on commercial buildings out of hours?

Yes. We carry out commercial flat roof repairs in the evening, at weekends and on bank holidays where the building is occupied during normal trading hours. Tell us your operating pattern when you call and we will quote around it.

How much does a flat roof repair cost?

The honest answer is that it depends on the size of the area, the system in place, access and what we find when we open it up. We do not give over the phone numbers because they are usually wrong. What we do give you is a free survey, a written report and a fully itemised quote, so you can see exactly what you are paying for before you commit. You can also get an indication using our online flat roofing quote tool.

Can I claim a flat roof repair on my insurance?

If the damage was caused by a sudden event like a storm or impact, your insurer will often cover it. Gradual wear and tear is usually not covered. We give you a written report with photographic evidence of the damage either way, which helps your conversation with the insurer go a lot more smoothly.

Does poor insulation cause flat roof leaks?

Not directly, but it does increase the risk of condensation. A cold roof void with no proper ventilation creates interstitial condensation that rots the deck from the inside. When we quote a repair we look at the flat roof insulation too and tell you whether it is part of the problem.

Will you try to sell me a new roof when I just want a repair?

No. We make our money by being the flat roof specialists people come back to. If your roof needs a repair, we quote you for a repair. If it needs replacing, we will tell you that too, and explain why, so you can make the call with both eyes open.

Book Your Free Flat Roof Repair Survey

A leak is not going to fix itself, and the longer it goes the more it costs. Book a free 10 point flat roof condition survey today and you will get a straight answer on what is wrong, what it will take to fix and what it will cost. No pressure, no pushy sales pitch, no surprises.

Call 01753 303775 to speak to a flat roofing specialist Or book your free survey online