Roof Evidence & Repair Guide
Clear roofing answers backed by the evidence you should look for before deciding what work your roof actually needs. Every answer sets out what may be visible, what it can mean, what else could explain it, and what you should be shown before agreeing to anything.
In-depth guides
- How to find the source of a roof leakA step-by-step method for tracing a roof leak back to its real entry point, why the stain is rarely below the fault, and when a drone survey is the faster answer.Read the guide → How to find the source of a roof leak
- Storm damage roof checklist for Cumbria and the BordersWhat to check after a named storm, how to make a property safe, what evidence insurers ask for, and which roof defects turn a small repair into a large one if left.Read the guide → Storm damage roof checklist for Cumbria and the Borders
- Repair or replace: how to judge whether a roof is finishedThe practical tests that separate a roof worth repairing from one at the end of its life: nail fatigue, delamination and underlay condition.Read the guide → Repair or replace: how to judge whether a roof is finished
- Drone roof inspections: what they show and when they are worth itHow a drone roof survey works, what the images reveal that a ladder cannot, why it suits landlords and remote owners, and the rules UK operators work under.Read the guide → Drone roof inspections: what they show and when they are worth it
Show me what’s wrong with my roof
Pick the closest description of what you can see. You will get the questions worth asking, what the evidence could mean, and where to read more. This is signposting, not a diagnosis of your property — only an inspection can confirm a cause. Never climb onto a roof to check.
› Water stain on a ceiling or wall
Worth asking
- Does it appear only after rain from one particular direction?
- Is it near a chimney, a valley, or an external wall head?
- Is the loft timber above it wet, or only the plaster below?
What it could mean
- Water entering higher up the roof and running along a rafter before it drops.
- A failed flashing at a chimney or abutment rather than a failed covering.
- Condensation or an overflowing gutter rather than a roof leak at all.
› Missing or slipped slate
Worth asking
- Is it one slate, or several across different slopes?
- Did it follow a named storm, or appear with no obvious cause?
- Are there slate fragments or mortar in the gutters?
What it could mean
- An isolated fixing failure that a targeted repair will resolve.
- Nail fatigue across the slope, where repairs keep moving the problem sideways.
› Broken or cracked tile
Worth asking
- Is the break isolated, or are neighbouring tiles crazed as well?
- Is the ridge or verge mortar cracked nearby?
What it could mean
- Impact or frost damage to a single tile.
- A covering reaching the end of its serviceable life.
› Damp around a chimney
Worth asking
- Is the flashing lead, or a mortar fillet?
- Is the brickwork spalled or the pointing eroded?
- Does the damp show on the chimney breast inside?
What it could mean
- A cracked mortar fillet holding water against the joint.
- Saturated brickwork or a failed back gutter rather than the flashing itself.
› Sagging or uneven roof line
Worth asking
- Is the dip local to one area, or along the whole ridge?
- Has it changed recently, or been there for years?
What it could mean
- Historic settlement that is stable and does not need work.
- Deflected or decayed timber that needs internal inspection to confirm.
› Moss on the roof
Worth asking
- Is it surface growth, or thick enough to lift the tail of a tile?
- Is moss debris blocking the gutters or downpipes?
What it could mean
- Cosmetic growth that needs nothing doing to it.
- Build-up holding water against the covering and blocking rainwater goods.
› Overflowing gutter
Worth asking
- Does it overflow in one spot, or along the run?
- Is the gutter sagging away from the fascia?
- Is the fascia or soffit behind it soft or discoloured?
What it could mean
- A blockage that clearing will resolve.
- Falls or brackets that have failed, saturating the wall head and roof timbers.
› Flat roof problem
Worth asking
- Is water standing on the surface long after rain?
- Are there blisters, splits, or lifted seams?
- Is the leak at the upstand where the roof meets a wall?
What it could mean
- Falls that no longer shed water, so the covering stays wet.
- A failed detail at the upstand rather than the field of the roof.
› Damage after a storm
Worth asking
- Is the roof open to the weather now?
- Can you see displaced slates, lifted ridge, or rippled flashing from the ground?
- Have you photographed and dated what you can see?
What it could mean
- Damage needing making safe before any permanent repair is scoped.
- Pre-existing wear brought to light by the storm rather than caused by it.
› Nothing obvious — I want the roof checked
Worth asking
- Is this before a purchase, a sale, or a letting?
- Is access difficult, or the roof high or steep?
- Do you need documentation you can keep and share?
What it could mean
- A photographic survey may answer the question without scaffolding.
- Imagery documents visible condition; concealed timber, underlay and fixings still need closer investigation.
Topics in this guide
The guide is organised around the questions homeowners actually ask. Where a topic already has a full Elite resource, it is linked below.
What a failing roof actually looks like from the ground, from the loft and from above — and what each sign can and cannot tell you.
Tracing water back to where it actually gets in, separating roof leaks from condensation and rainwater goods, and confirming the cause before paying for a repair.
What roofing photographs should show, what they can prove, what they cannot, and how to read the evidence behind any recommendation you are given.
The evidence that points to an isolated repair, the evidence that points to renewal, and the questions that separate the two honestly.
What genuinely moves the price of roofing work, what a written scope should contain, and how to compare quotations that are not describing the same job.
What to do while a roof is open to the weather, what counts as storm damage, and what evidence supports an insurance discussion.
What actually extends the life of a roof here, what shortens it, and how often a roof in this climate is worth checking.
How to check who is climbing onto your roof, what a written scope should say, and what to be shown before you agree to anything.
What an inspection can document, what a drone can and cannot show, and what you should receive at the end of one.
Drone Imagery as Roof Evidence
What aerial imagery is worth once the inspection is over: the record you keep, how it supports a second opinion, and where it stops.
The leak is almost never directly above the stain
Water entering a roof runs down the underside of the membrane, along a batten or a rafter, and drops at the first obstruction. By the time it reaches a ceiling it can be several metres from where it got in.
That is why a repair aimed at the visible damp patch so often fails. Before anything is fixed, someone needs to trace the path back — in the loft where there is access, and on the roof itself where there is not.
- Check the loft during rain, with a torch, and look for running water rather than staining.
- Photograph the wet timber before it dries — the trail is far easier to read when wet.
- Note whether the leak appears only in driven rain from one direction; that usually points to flashings or verges rather than the covering.
What storm damage actually looks like from the ground
After a named storm the roofs that fail are usually the ones that were already marginal. You can do a useful ground-level check without going anywhere near a ladder.
- Slates or tiles missing, lifted, or sitting at a different angle to their neighbours.
- Ridge tiles with mortar cracked or gone, or a visibly uneven ridge line.
- Debris in the gutters — fragments of mortar or slate mean something above is breaking up.
- Lead flashing lifted away from the wall or rippled along a chimney.
- Fresh damp on chimney breasts and around ceiling roses inside.
Repair or reroof: how to decide honestly
A roof is worth repairing when the covering is broadly sound and the failures are localised — a handful of slipped slates, one failed flashing, a cracked fillet. It is worth replacing when the fixings have reached the end of their life across the whole slope, because then every repair simply moves the problem a metre sideways.
The clearest sign of a roof at the end of its life is nail fatigue: slates slipping in different places every few months with no storm to blame. If you are repairing the same roof three or four times a year, you are paying for a reroof in instalments and getting none of the benefit.
Cement, sealant and other short-term fixes
Mortar fillets and mastic get used because they are quick and cheap. Both are rigid, both are exposed to constant thermal movement, and both crack. Once cracked they hold water against the joint instead of shedding it, so the second failure is usually worse than the first.
Properly dressed code-rated lead does the same job and lasts decades. If someone quotes to seal a chimney junction with cement, ask what happens when it cracks — and ask for the lead price alongside it.
Gutters cause more 'roof leaks' than roofs do
Blocked or sagging gutters overflow against the wall head, saturate the fascia and soffit, and rot the roof timbers from the edge inwards. It presents inside as damp at the top of a wall and gets mistaken for a roof covering failure.
Clearing gutters twice a year — after leaf fall and in late spring — prevents a large share of the damage we get called out to.
Checking a roofer before you commit
Roofing attracts doorstep traders because the work is largely out of sight. A few questions filter most of them out.
- Ask for the registered company name and number, then check it on Companies House.
- Ask for public liability insurance and, if they have employees, employers' liability.
- Ask for photographs of the actual fault on your roof before agreeing to anything.
- Get the quotation in writing with materials specified, and never pay in full up front.
- Be wary of anyone who found a fault on your roof while passing and needs a decision today.
Roof maintenance calendar for an exposed Cumbrian property
Roofs here take sustained wind-driven rain rather than occasional extremes. Small, regular checks are worth far more than a single inspection every ten years.
- Autumn: clear gutters and downpipes, check for slipped slates before the winter gales.
- Winter: after each significant storm, do a ground-level and loft check.
- Spring: clear moss debris from gutters, look at ridge and verge mortar for winter cracking.
- Summer: the right time for planned work — flat roof renewals and reroofs need dry, settled weather.
General roofing questions
Looking for something specific? Browse our roofing services or read the full FAQ.