What Do You
Know, Joe?
Hard-won lessons from three decades on London’s rooftops. No textbooks. No theory. Just the real knowledge that keeps rain out and roofs standing.
From Market Stalls to Master Roofer
Joe didn’t learn roofing from a course. He learned it the way all real roofers used to — starting at the bottom and working every job until the craft was in his hands.
He was thirteen when he first climbed onto a roof. Before that, he’d been cleaning windows and running errands at market stalls — doing whatever paid. Roofing wasn’t a career plan. It was work that was there, and Joe was the type to show up.
He spent years learning under experienced roofers at Gal Star Roofing, one of the companies where the old hands still taught properly. That meant starting with the basics: carrying tiles, mixing mortar, watching how lead was dressed around a chimney stack and understanding why each step mattered, not just what it looked like.
By his early twenties, Joe was independent. He built his reputation the old-fashioned way — door to door, street by street, roof by roof. No Yellow Pages advert. No website. Just work that spoke for itself, and customers who told their neighbours.
Over the years, that reputation grew into contracts with Citibank, churches across London, housing associations, and hundreds of private homes from Barnet to Islington. At peak, Joe ran crews of up to nine roofers — but he never stopped getting on the roof himself.
Every roof you put on is a shop front. The whole street can see your work. You want another job on that street? Then the first one has to be perfect.— Joe, Master Roofer
Today, Joe brings that same standard to MJM Roofing. He’s the reason we don’t cut corners, don’t use sealant where lead should go, and don’t send someone to your roof unless he’s personally confident in their work. When Joe looks at your roof, he’s not reading from a checklist. He’s drawing on thirty years of seeing what goes wrong — and knowing exactly how to make it right.
What Three Decades on a Roof Teaches You
These aren’t tips from a blog. These are lessons Joe learned the hard way — on scaffolding, in the rain, fixing other people’s mistakes.
You Can Tell a Roofer by His Leadwork
Lead flashing is the most expensive material on any roofing job and the hardest to work properly. It needs to be dressed, bossed, and shaped by hand. The quality of a roofer’s leadwork reveals years of experience — or the lack of it. When lead is installed without a proper underlay, or coated without patination oil, it corrodes and can contaminate a home’s water system.
Most Roof Problems Start Small
A slipped tile. A hairline crack in the flashing. A gutter that’s silted up. These are the things that, left alone for a season, turn into a damp patch on the bedroom ceiling. Joe has lost count of the jobs where a £200 repair became a £5,000 problem because nobody looked at it when it first appeared.
Cheap Repairs Always Cost More
Joe has a rule: if someone’s fixed a lead flashing with silicone sealant, he knows he’ll be back within six months. The roofer who charged £150 and bodged it didn’t fix the problem — they delayed it and often made it worse. Joe regularly arrives at homes where two or three other roofers have already visited, collected their callout fee, and left without solving anything.
Flat Roofs Get Blamed for Bad Roofers
The myth that flat roofs always leak is one Joe has heard his entire career — and he’s tired of it. A properly installed GRP or EPDM flat roof can last decades without a single issue. The problem is never the concept of a flat roof. It’s the installation: wrong falls, poor edge detailing, membranes that aren’t bonded correctly.
Conservation Areas Change Everything
Across North London — from Highgate to Hampstead to parts of Barnet — conservation areas and listed buildings come with strict requirements for roofing materials. You can’t just use any tile. Local planning laws may require specific slate types, traditional fixing methods, or exact matches to the rest of the street.
The Glossy Website Doesn’t Guarantee the Work
Joe has seen the pattern repeatedly: a company has a slick website, professional photos, five-star template reviews — and when they show up, they’ve sent agency workers who’ve never laid a tile. There’s a disconnect between how a company presents itself online and the quality of work that actually arrives at your door.
Concerned About Your Roof?
Joe and the MJM team offer free roof inspections across North London. No pressure, no obligation — just honest advice.
Roofing Myths Joe Has Heard a Thousand Times
After thirty years, Joe’s heard every roofing myth going. Here are the ones that cost homeowners the most money.
“My roof needs completely replacing.”
In Joe’s experience, most roofs don’t need a full replacement. They need targeted maintenance — re-bedding a ridge, replacing cracked tiles, re-dressing lead flashings. A well-maintained roof can last fifty years or more. The full replacement pitch is often a sign that the roofer either can’t diagnose the actual problem or wants a bigger invoice.
“You can fix anything with sealant.”
Silicone sealant is one of the most misused products in roofing. Joe calls it the cowboy roofer’s best friend. Sealant degrades with UV exposure, cracks in cold weather, and peels away from surfaces within months. When it’s used in place of proper lead flashing or correct tile replacement, it doesn’t fix the problem — it hides it until the next heavy rain.
“All slates are basically the same.”
The difference between a £1 slate and a £10 slate is enormous. Cheap riverbed slates are brittle, prone to cracking, and won’t last half as long as proper quarried Welsh slate. Welsh Blue and Welsh Penrhyn are denser, thinner, and easier to work with — they can last well over a century. On a listed building or in a conservation area, cheap slate won’t just perform poorly. It may not even be legal to use.
“Flat roofs only last ten years.”
This was arguably true decades ago, when most flat roofs were laid with basic roofing felt. Modern flat roofing systems — GRP fibreglass, EPDM rubber membrane — are engineered to last twenty to forty years when installed correctly. Joe has GRP flat roofs still going strong after two decades. The lifespan isn’t determined by the roof type. It’s determined by the roofer.
When Cutting Corners Costs Thousands
Joe doesn’t tell these stories to scare anyone. He tells them because they happen every week — and they’re almost always preventable.
The Silicone Chimney
North London — Residential PropertyA homeowner called Joe after water started coming through their bedroom ceiling near the chimney breast. They’d already paid two other roofers to fix it — over £300 spent, problem still there.
The previous roofer had sealed the entire chimney flashing with silicone instead of replacing the lead. The silicone had cracked in three places. Underneath, the original lead was corroded because it had never been coated with patination oil, and there was no underlay. Water had been tracking down the inside of the chimney breast for months, soaking the timber.
Joe stripped the failed silicone, removed the corroded lead, installed new code 4 lead with proper soakers and step flashings, applied patination oil, and fitted a lead underlay to prevent future condensation damage. The job that should have been a £400 repair had become over £2,000 — because the first roofer reached for the sealant gun instead of doing the job properly.
Two or three roofers had already been there, charged £150 each, and didn’t fix a thing. They couldn’t fix it. They just wanted the callout fee.— Joe, on a common pattern he sees
Joe’s Advice for Every Homeowner
Thirty years of roofing distilled into the advice Joe gives his own family. No sales pitch — just what actually matters.
Check Your Roof Once a Year
You don’t need to climb up there. From the ground, look for slipped tiles, sagging ridge lines, moss buildup, and cracked mortar around chimney stacks. Binoculars work well. If something looks wrong, get a professional to check it before winter.
Never Ignore a Small Leak
A damp patch on the ceiling or a water stain in the loft might look minor. But water that’s coming through your roof has already found a path — and it’s getting wider. Early action means a simple repair. Delayed action means timber damage, mould, and a much bigger bill.
Don’t Choose the Cheapest Quote
Joe’s seen it hundreds of times: the cheapest roofer uses the cheapest materials, spends the least time, and leaves you with a problem that comes back within a year. A roof is a long-term investment. Ask questions, check their previous work, and if they can’t explain what they’re going to do and why — don’t hire them.
Ask About Leadwork Specifically
The areas where roofs leak most are the junctions — around chimneys, at abutments, in valleys. These all require proper lead flashing. Ask your roofer what code lead they’ll use, whether they’ll apply patination oil, and if they’ll install an underlay beneath the lead. If they can’t answer these questions, they’re not the right roofer.
Keep Your Gutters Clear
Blocked gutters are one of the most common causes of water damage that gets blamed on the roof. When gutters overflow, water runs down walls, seeps into mortar, and can eventually reach the internal structure. Clearing your gutters twice a year — autumn and spring — is one of the cheapest ways to protect your home.
If a Roofer Won’t Explain the Problem, Walk Away
A good roofer should be able to tell you exactly what’s wrong with your roof and exactly what they’re going to do about it — in plain English. If someone’s vague about the problem, unclear about materials, or rushes to give you a price without a proper inspection, that’s a warning sign.
Learn More from Joe’s Expertise
Each of these guides is drawn from Joe’s real experience. Practical roofing knowledge for London homeowners.
7 Warning Signs Your Roof Is About to Leak
The early indicators Joe checks for on every inspection — and what you can spot from the ground.
Why Leadwork Is the True Test of a Roofer
What proper lead flashing looks like, why it matters, and how to tell if yours has been done right.
Why the Cheapest Roof Repair Quote Costs You More
Real examples of how patch jobs and corner-cutting lead to bigger bills down the line.
Flat Roof Myths: What London Homeowners Get Wrong
GRP, EPDM, and felt compared — plus why flat roof failures are almost always installation failures.
Roofing in London Conservation Areas: What You Need to Know
Planning restrictions, approved materials, and why your postcode determines your roofing options.
Slate vs. Tile: A London Homeowner’s Guide
From Welsh Blue at £10 a slate to Redland 49 concrete tiles — what suits your property and budget.
How to Spot a Cowboy Roofer Before They Start
The red flags Joe has learned to recognise — and what to ask before you hire anyone.
The Annual Roof Inspection Checklist for London Homes
A five-minute check that saves thousands. What to look for, when to look, and when to call a pro.
Want Joe’s Eyes on Your Roof?
MJM Roofing offers free, no-obligation inspections across North London — Islington, Camden, Highgate, Hampstead, Barnet and surrounding areas.