First-time buyers typically obsess over kitchens and bathrooms. Fair enough. But the expensive problems are above your head, not under your feet.
A new kitchen costs £8,000. A full roof replacement on a Victorian terrace? Try £15,000 to £25,000. And that’s before you discover the chimney needs rebuilding or the brickwork needs repointing across the entire front elevation.
Here’s what you need to check before you commit to a property, and what to do when your surveyor’s report flags concerns.
Why Your Standard Survey Won’t Catch Everything
Most first-time buyers get a Level 2 (Homebuyer) survey. The surveyor inspects the roof from ground level using binoculars. They’re not climbing up there. They’re not checking every tile. They’re giving you a visual assessment from 20 feet away.
If there’s obvious damage, they’ll flag it. But hairline cracks in flashing? Early signs of membrane failure on a flat roof? Deteriorating mortar on the chimney stack? These often get missed until they become serious problems.
This isn’t a criticism of surveyors. It’s just the reality of what a £500 survey covers versus what a specialist roof inspection involves.
What You Can Check During Viewings
You don’t need to be a roofing expert to spot warning signs. Here’s your viewing checklist.
Inside the Property
Start in the loft if you can access it. Look up, not just around at the stored Christmas decorations.
Check for:
- Water stains on the underside of the roof (dark patches, tide marks)
- Daylight visible through gaps in the tiles or slates
- Sagging or bowing in the roof timbers
- Condensation or a damp, musty smell
Now check the ceilings in every room. Water damage doesn’t always show up where you’d expect it. It can travel along timber before appearing as a stain.
Red flags:
- Brown or yellow ceiling stains
- Bubbling or peeling paint on ceilings near external walls
- Cracks radiating from corners (could indicate movement)
Outside the Property
Walk around the entire building. Don’t just look at the front.
Roof condition:
- Missing, cracked, or slipped tiles or slates
- Sagging roofline (this is serious)
- Moss buildup (not always a problem, but heavy moss retains moisture)
- Damaged or missing ridge tiles
Chimneys:
- Leaning chimney stacks
- Crumbling mortar between bricks
- Missing or damaged chimney pots
- Flashing that’s pulled away from the brickwork
Gutters and downpipes:
- Plants growing out of gutters (means they’re blocked solid)
- Visible rust or holes in metal gutters
- Gutters pulling away from the fascia
- Staining on walls below gutters (suggests overflow)
Walls and pointing:
- Cracks wider than a £1 coin
- Crumbling mortar between bricks
- White powdery deposits (efflorescence, indicates damp issues)
- Bulging or bowing in walls
Windows and doors:
- Rotten timber around frames
- Gaps between frame and wall
- Paint that’s cracked and peeling (suggests water ingress)
Flat Roofs and Extensions
Flat roofs are common on rear extensions and garages. They’re also a frequent source of problems.
Warning signs:
- Pooling water (flat roofs should have a slight fall)
- Cracks or blisters in the surface
- Felt that’s lifting at the edges
- Green algae growth (indicates standing water)
A well-maintained flat roof should last 15 to 20 years. Ask the vendor when it was last replaced. If they can’t remember or it’s over 20 years old, budget for replacement.
When to Commission a Specialist Roof Survey
Your surveyor’s report arrives. It flags “further investigation recommended” for the roof. What now?
This is where you need a specialist roof survey in London before you exchange contracts. Not after. Before.
A detailed roof inspection includes:
- Ladder or scaffolding access to inspect tiles and slates up close
- Checking the condition of all flashings and leadwork
- Assessing chimney condition from roof level
- Often drone photography for difficult-to-access areas
- Thermal imaging to identify hidden leaks in flat roofs
You’ll get a written report with photographs showing exactly what needs doing and realistic cost estimates. This isn’t about killing the sale. It’s about negotiating properly or budgeting correctly.
Scenarios where specialist inspection is essential:
- Property over 50 years old and roof looks original
- Visible damage to tiles, slates, or chimney
- Any mention of “further investigation” in your survey report
- Listed building or property in a conservation area
- Flat roof extension over 15 years old
- Buying at auction (no survey period to back out)
Heritage and Period Property Considerations
Georgian and Victorian properties need different attention. They weren’t built with modern materials, and they shouldn’t be repaired with them either.
If you’re buying a listed building or a property in a conservation area, standard modern repairs might not be permitted. Replacing original slate with concrete tiles or using cement mortar instead of lime can cause long-term damage and may require planning permission to correct.
What to check on period properties:
- Are the original sash windows still in place? (Replacement can be restricted)
- Has the roof been recovered with inappropriate materials?
- Is the pointing cement-based? (Should be lime mortar for breathability)
- Are there Article 4 Directions limiting permitted development?
Heritage roofing specialists understand these requirements. Using the wrong contractor can leave you with expensive mistakes that need undoing.
Red Flags That Should Stop You Proceeding
Some issues are fixable. Some should make you walk away or renegotiate substantially.
Walk away if:
- Structural movement in walls or roof
- Extensive rot in roof timbers visible in the loft
- Subsidence (unless you’re buying at a significant discount and accept the risk)
- Entire roof needs replacing and there’s no money in your budget
Renegotiate if:
- Repointing needed across large sections of brickwork (£3,000 to £8,000+)
- Chimney requires rebuilding (£2,000 to £5,000)
- Flat roof needs replacement (£1,500 to £4,000 for a typical extension)
- Gutters and downpipes need replacing (£1,000 to £2,500)
- Lead flashing around chimney needs replacement (£800 to £1,500)
Get quotes for the work. Then negotiate either the purchase price down or ask the vendor to complete the repairs before completion.
Exterior Maintenance You’ll Be Taking On
Once you own the property, you’re responsible for keeping the roof and exterior maintained. Here’s what that involves.
Annual checks:
- Clear gutters and downpipes in autumn
- Check for loose or damaged tiles after storms
- Inspect chimney pointing
- Clear moss from paths and walls
Every 3 to 5 years:
- Repaint external woodwork (fascias, bargeboards, window frames)
- Check and repair pointing where needed
- Service or replace gutter brackets
Every 10 to 15 years:
- Replace flat roof membranes
- Consider gutter replacement if they’re cast iron and deteriorating
As needed:
- Replace broken tiles or slates immediately
- Repair damaged flashing
- Address any damp issues promptly
Making the Decision
You’ve done the viewing. You’ve read the survey. Maybe you’ve commissioned a specialist inspection. Now you’re armed with actual information instead of vague worries.
If the property needs £5,000 of roofing work but it’s £15,000 under market value, that’s still a good deal. If it needs £20,000 of work and you’ve no budget for it, walk away. There are other houses.
The worst scenario is buying blind, moving in, then discovering problems you could have negotiated on or avoided entirely.
First-time buyers who take roof and exterior condition seriously save themselves tens of thousands in unexpected repairs. Those who focus only on the cosmetic stuff get expensive surprises.
Choose wisely.
