Greater London · London and the South East
Harlesden Roof Leak Investigation
We carry out roof leak investigations in Harlesden and the rest of Greater London. We survey seven days a week.
- Leaks at a dormer or roof window
- Water dripping from rafters or underlay
- Condensation that looks like a leak
Roof leak investigation in Harlesden
A leak that comes and goes can be the hardest to pin down. Wind-driven rain, an overflowing gutter or snow melt may be what triggers it. Telling us when it happens helps a lot, along with any photos you’ve taken. We look for the clues it leaves behind, like tide marks, stained timbers and damp underlay. Moisture detection shows which materials are still damp. If you’ve noticed water dripping from rafters or underlay and brown rings on upstairs ceilings, we can find out what’s behind it.
Water getting into a London home often comes from a detail you can’t see from the street: a butterfly roof’s central valley gutter, a parapet gutter, a chimney flashing or a flat roof over a back addition. For a leak or storm damage in Harlesden, those hidden details are where the inspection begins. Water from a hidden gutter can run along joists and show up a room or two away.
The written findings come by email, ready to forward to whoever needs them. Basic reports come within 48 hours, Standard within 24–48 hours and Premium on the day.
- Location
- Harlesden (NW10, W3, NW26)
- Wider area
- Greater London
- Prices
- From £150 inc. VAT
- Report
- Emailed report with photos and recommendations
- Appointments
- Weekdays, Saturdays and Sundays
- Insurance
- Professional indemnity and public liability
- Phone
- 07833 053749
- Updated
- 27 October 2026
The survey, step by step
You don’t need to do much on the day. Show us any stains, drips or problem areas you know about, and we’ll take it from there. The survey itself takes roughly 1–2 hours, more where the leak is intermittent or the roof is large. London terraces rarely offer a view of the whole roof from one spot, so in Harlesden we work round the house, using the street, the windows, the loft and any safe vantage point behind it. If other people live in the building, let us know who can let us into the shared parts.
- We start with what you’ve seen: where the stain is and when it gets worse.
- The visit starts indoors, at the stain and in the loft.
- Likely entry points outside are looked at, from flashings and valleys to gutters and outlets.
- We use moisture detection, and thermal imaging where it is useful.
- You receive a written report with photos showing the likely source and what needs attention.
Preparing for the visit
- Gather any invoices or paperwork from past roof work
- For a flat or shared roof, check access with the freeholder or managing agent
- Make sure we can get to the back of the property
Arrange a survey
A quick phone call is usually the easiest start: phone 07833 053749 or send us an email and we’ll ask a few questions about the roof. The price is agreed before a date is set.
Advice
Different roofs, different checks
Flat roof upstands and outlets
Outlets drain a flat roof. When one blocks, water ponds and finds any weak spot. Outlets and the area around them are checked.
Chimney stacks
Our chimney check is a visual inspection of the stack, not a flue, gas or sweep inspection.
When to book a survey in Harlesden
A roof valley collects the rain from two slopes. Worn lead, cracked linings or a build-up of leaves and moss can push water under the slates or tiles. Leaks from valleys often show up some distance away inside.
Here are some of the things we see frequently:
- Leaks at a dormer or roof window
- Water marks that spread in wet weather
- Wet patches high on an inside wall
- Condensation that looks like a leak
Homes near green spaces such as Roundwood Park can get more leaves in their gutters in autumn, so outlets and downpipes are worth watching.
Before booking anyone
- Whether VAT is in the quoted price
- What happens after the report arrives
- Do they have a CAA Flyer ID and Operator ID for drone work?
- Which viewpoints they use to see the roof
DIY checks: what’s safe
Keep a simple record: when leaks happen, ground-level photos and any past roof work. Share it with us as you book, as it helps us focus the survey.
After strong wind, take a look from the pavement or garden: broken slates or tiles in the garden, gaps along the ridge or loose lead are signs to note. Leave anything above ground level to a survey.
When you need someone else
Every survey has limits, and it is better to know them up front. Keep these in mind:
- An intermittent leak that shows no trace on the day
- Whether rotten timbers meet design loads
- Water from pipes, tanks or heating systems
If in doubt, ring 07833 053749 or drop us an email and we’ll recommend the right survey before you book. What a survey covers and doesn’t.
Roof types and parts we check
- Slate and tile slopes
- Chimney stacks
- Valleys and parapet gutters
- Lead flashings
- Flat roof details
- The roof space
- Rooflights and dormers
Harlesden questions
Does a conservation area affect roof work in Harlesden?
Historic England’s list shows listed buildings, and the local council can tell you about conservation areas. If a home is listed, changes that affect its special interest need listed building consent, and in a conservation area re-roofing in different materials may need permission.
Is Harlesden in the area you cover?
Yes. We work right across London and South East England, and Harlesden is part of that. Just ring 07833 053749 or email us and tell us about the property, and we’ll talk through which survey suits.
Is it a structural engineer’s report?
No. We point out what can be seen, such as sagging or deflection, but we’re not structural engineers and do not carry out calculations. If we think you need an engineer, the report says so.
What will the report tell me?
A photo-illustrated written report, covering the condition of the leaking roof, the defects we found and what we recommend, by urgency where it matters. Standard adds moisture detection and a structural check; Premium adds thermal imaging, drone inspection where applicable and structural analysis.
How do you tell a leak from condensation?
The two can look alike. Drips from nail tips, damp underlay over a wide area and poor loft ventilation point towards condensation. We look at the pattern, take moisture readings and tell you which is more likely.
Do you test for asbestos?
No. Our report may flag materials that could contain asbestos, but confirming it is a job for a specialist asbestos surveyor. Buildings built or refurbished before 2000 may contain it.
Is the repair included in the leak investigation?
A leak investigation finds and reports the likely source. The repair is not part of it. The report shows where the water gets in and what should be done.
Also near Harlesden
What else we do in Harlesden
Wind, rain and roofs in Harlesden
Historic houses such as Pitzhanger Manor, about 3.1 miles south-west, show how far back building in the area around Harlesden goes. On older houses around here, roofs often carry the marks of earlier repairs, from replaced slates to new lead, and the council can say whether a home is in a conservation area. In outer London, interwar semis with hipped, tiled roofs sit alongside older slate-roofed terraces. If your home in Harlesden is one of them, bay roofs, hips and later dormers each have their own details. The covering and its details give the first clues when tracing where water is coming from.
For an older house near a landmark such as Church of All Souls, old mortar, worn lead and slipped slates are the usual suspects when water gets in. If you own a rental within reach of Willesden Junction station, a tenant living with a leak needs the cause found, not just the stain painted over.
Harlesden is about 4 miles west of City of Westminster, in Greater London. We survey roofs in Harlesden and the surrounding area as part of our work across London and the South East. Harlesden is one of the places in Greater London where we work. For surveys nearby, see our London page.
Postcode districts we cover here for roof leak investigations: NW10, W3 and NW26. That includes homes and businesses on Fry Road, Wood Road and Park Road and the roads around them. Neighbouring places we cover for roof leak investigations include College Park (1 mile south-east), Old Oak Common (1 mile south), Church End (1 mile north), Stonebridge (1 mile north-west) and Willesden Green (1 mile north-east). Larger places within reach include London (7 miles east), City of Westminster (4 miles east), Marylebone (5 miles east), Kensington (3 miles south-east), St Pancras (6 miles east) and Shoreditch (7 miles east).
What’s near Harlesden
Locally, jobs take us to homes and businesses close to St Claudine's Catholic School for Girls, Royal Oak Inn and Roundwood Park, among other places. There is a railway station in Harlesden itself: Willesden Junction station. Other landmarks nearby include Central Middlesex Hospital (1 mile west) and Brent Museum and Archives (1.1 miles north-east). Open spaces near Harlesden include Castlebar Hill and The Long Water.
Leave it or get it looked at?
A leak that returns after a repair typically means the real source wasn’t found. We look past the obvious spot and check each likely route. That’s often what breaks the cycle. London’s older roofs often have bitumen felt underlay or none at all, so once the slates or flashings let water past, little stops it reaching ceilings. Left alone, that means wet timbers and plaster, which is a far bigger job than the roof fault itself.
A Basic Survey starts from £150, with VAT included. Standard is from £250 and Premium from £400, both inc. VAT. We confirm the price for your roof before you book.
Why us?
- Customer satisfaction of 98%
- Surveys on any day of the week
- Plain-English reports with photos
- More than 20 years surveying roofs
Read our cost guide and what we found on two real jobs.