Emergency roof repairs available 24/7 — Call now: 0239 307 1334
★ 4.9/5 · 127 Google Reviews · Portsmouth Roof Cleaning Specialists

Roof Cleaning & Moss Treatment Portsmouth

Moss and lichen treatment, biocide application and roof cleaning across Portsmouth and the Hampshire coast. Portsmouth's coastal humidity means moss grows faster and causes damage sooner than in inland towns — leaving it untreated accelerates mortar failure, cracked tiles and blocked valleys. We use soft-wash biocide treatment, not high-pressure washing that damages older tile surfaces.

📅 Get My Free Quote — Callback Within 2 Hours

Tell us the job in 30 seconds. No pushy sales, no call-out fee.

📞 Call Now: 0239 307 1334

Roof cleaning in Portsmouth uses soft-wash biocide, never pressure washing which damages tiles. Treatment lasts 2 to 4 years and costs £200 to £750 by roof size. We check nail sickness on post-war estates at the same time. Free assessment — call 0239 307 1334.

✓ NFRC Registered
✓ Fully Insured
✓ 10-Year Guarantee
✓ Free Quotes
✓ No Hidden Costs
✓ Family Run Since 2003
Roof RepairsRoof ReplacementFlat RoofingEmergencyRoof InspectionsLead RoofingChimney RepointingGutteringGutter CleaningFascias & SoffitsMoss RemovalVelux & SkylightsDry VergeLandlord RoofingCommercial
Roof Cleaning Portsmouth

Moss Treatment and Roof Cleaning Across Portsmouth

Portsmouth is one of the highest moss-load environments for roofing in south Hampshire. Coastal humidity, significant annual rainfall, salt-laden air that encourages biofilm growth on tile surfaces, and the prevalence of north-facing slopes in the back-to-back terrace format of Fratton, North End and Southsea create conditions where moss and lichen establish and spread faster than in drier inland towns.

Left untreated, moss does structural work over time. It retains moisture against mortar pointing, accelerating freeze-thaw cycling that cracks bedding mortar on ridge and valley tiles. In valley gutters, moss acts as a dam, backing water up under tile courses and causing leaks that are difficult to trace. The correct treatment — soft-wash biocide application — kills the moss at the root, after which it dies and weathers off over 3 to 6 months without the tile surface damage caused by pressure washing.

Our Roof Cleaning Process

  • Full roof inspection — identify any repair issues before treatment
  • Soft-wash biocide application to all affected tile areas
  • Valley and gutter clear — removing accumulated debris
  • Ridge and hip mortar check while on the roof
  • Post-treatment report with photographs

Roof Cleaning Costs in Portsmouth

  • Biocide moss treatment (standard semi): £200 to £350
  • Biocide treatment (larger detached): £350 to £550
  • Soft-wash cleaning with biocide (heavily affected): £300 to £500
  • Gutter clear included with all roof cleaning visits

Free Roof Moss Assessment

Moss on your Portsmouth roof? We assess the load, identify any underlying repair issues, and quote treatment in writing.

0239 307 1334

Mon–Fri 8am–6pm · Sat 8am–2pm · 24/7 Emergency

Customer Reviews

What Customers Say About Our Roof Cleaning?

★★★★★

"North-facing rear slope on our Fratton Victorian was completely green. Portsmouth Roofing did the biocide treatment and cleared the valley at the same visit. Four months later the moss has completely gone. Also spotted a ridge tile issue while up there."

Barbara T. · Fratton, Portsmouth
★★★★★

"Had a company quote for pressure washing our Cosham semi. Portsmouth Roofing specifically advised against it given the age of the concrete tiles — said it would do more harm than good. Did the soft-wash biocide instead. Tiles are clean and still intact."

Derek M. · Cosham, Portsmouth
★★★★★

"Paulsgrove semi with heavy moss on both rear slopes. Treatment done in two hours, gutters cleared at the same visit, written report with photos provided."

B. Clegg · Paulsgrove, Portsmouth
Honest advice

Is Roof Cleaning the Right Fix?

Moss and algae show as green or black growth across the tiles, especially on north-facing slopes, and as clumps of moss dropping into the gutters.

When it is not the answer: Pressure washing a tiled roof is never the answer — it drives water under tiles and strips the surface; soft-wash biocide is the only safe method Read the full guide.

Roof void ventilation path: air in at the eaves, out at the ridge, keeping the roof dry
Cross-flow ventilation keeps the roof void dry; blocked eaves cause the condensation "leak" with no hole.
Local factors

Local Factors in Portsmouth

Solent salt air and exposed Channel weather corrode fixings and lift tiles faster than inland Hampshire. Portsea Island's dense Victorian terraces mean rear elevations are often reached only through tight alleys, and front scaffold needs permit-controlled pavement space. It is why we specify marine-grade fixings and correct lead codes as standard on Portsmouth roofs — the coastal environment punishes anything less.

The process

What to Expect: Roof Cleaning in Portsmouth

1. Survey

We assess the growth, roof aspect and tile condition, and check for nail sickness on estate stock at the same time.

2. Written quote

An itemised quote for soft-wash biocide treatment — never pressure washing.

3. Scheduling

We book the treatment and arrange safe access.

4. The work

We scrape heavy growth by hand and apply a biocide that kills moss and algae at root level over several weeks.

5. Cleanup & sign-off

Gutters cleared of fallen debris and your work documented.

Timescales

Typical Timescales

JobTypical duration
Soft-wash treatment (semi)Half a day
Full clean and scrape (detached)1 day
Gutter clear add-on1–2 hours
Biocide root-kill periodSeveral weeks to fully work

Biocide needs a dry spell to work into the growth — we apply it ahead of settled weather where possible.

Access

Getting Safely onto Portsmouth Roofs

Roof cleaning works from towers or ladders with roof ladders for the slope; scaffold only on complex roofs. Scaffold is specified for: steep or high roofs where safe standing time is needed - always itemised in your written quote, never a hidden extra, and we arrange it.

Portsea Island's dense Victorian terraces mean rear elevations are often reached only through tight alleys, and front scaffold needs permit-controlled pavement space. Pavement scaffold and skip permits go through Portsmouth City Council; allow a few working days on streets like Albert Road, Fawcett Road, Marmion Road where space is tight.

Pricing

Portsmouth Roof Cleaning: Cost Guide

JobTypical rangeNotes
Slipped or cracked tiles£150–£350Per visit incl. access
Leak diagnosis & repair£150–£500Depends on water travel
Chimney flashing£200–£600Code 5–6 lead
Valley repair£400–£900Strip and re-lay
Nail-sickness re-fix (per slope)£600–£1,200Estate stock

What moves the price

Worked example: A typical job on a property off Albert Road in Portsmouth, including access and waste removal, sits in the middle of the ranges above once surveyed.

No deposit on repairs under £500. Staged payments on re-roofs — nothing up front before materials are on site. All prices include VAT; written itemised quote before any work.

Covering PO1, PO2, PO3, PO4, PO5, PO6 and surrounding postcodes.

Guarantee

Your Guarantee, Explained

Our workmanship is guaranteed; the biocide continues working for weeks and slows regrowth for two to four years by aspect.

If a fault appears in covered work, we come back and put it right. No quibbling, no re-charge.

Good to know

Living Around the Work

External-only work, no internal disruption — we protect planting below and clear fallen moss from gutters and paths. You do not need to stay home for external work - we just need power and access agreed in advance.

We soft-wash in dry conditions so the biocide isn't immediately rinsed off; coastal humidity means regrowth is slower after a proper root-kill. Solent salt air and exposed Channel weather corrode fixings and lift tiles faster than inland Hampshire.

FAQ

Frequently Asked Questions

Biocide moss treatment on a standard 3-bed semi in Portsmouth typically costs £200 to £450 depending on roof area and moss coverage. Full written quotes before we start.

We do not recommend high-pressure washing on older clay tiles, Welsh slate or concrete tiles with surface erosion — the water pressure removes the protective surface and accelerates decay. We use low-pressure soft washing and biocide treatment as standard.

Yes, over time. Moss retains moisture against mortar joints and tile surfaces, accelerating freeze-thaw cracking. Portsmouth's higher ambient humidity means moss growth is more aggressive than inland Hampshire and the structural consequences arrive sooner.

Biocide treatment typically lasts 3 to 5 years in Portsmouth's coastal conditions. Properties with north-facing slopes, heavy tree canopy or harbour-adjacent positions will need attention at the shorter end of that range.

Yes — we always include a gutter check and clear as part of a roof cleaning visit. Moss that has been treated sloughs off over 3 to 6 months and some will wash into gutters.

Yes free no-obligation written quotes on all work. No call-out fee. Call 0239 307 1334.

Yes. NFRC registered, fully insured, 10-year written guarantee on all work.

Coverage

Roof Cleaning — All Locations

Roof Cleaning FarehamRoof Cleaning GosportRoof Cleaning HavantRoof Cleaning WaterloovilleRoof Cleaning PortchesterRoof Cleaning SouthseaRoof Cleaning FrattonRoof Cleaning CoshamRoof Cleaning North EndRoof Cleaning Paulsgrove
Get In Touch

How Do I Get a Free Roofing Quote?

No call-out fees. No obligation. Just an honest quote from a local Portsmouth roofer.

0239 307 1334
Email Us Instead