Look at your roof. Do you see green patches on the north side? Thick moss growing between shingles? Dark streaks running down from the ridge?

Moss is not just ugly. It is destroying your roof.

I am Maninder Singh. I have seen thousands of Surrey roofs damaged by moss. I have also seen homeowners cause $15,000 worth of damage trying to remove moss themselves with pressure washers.

This guide compares DIY moss removal vs professional soft washing. You will learn what you can safely do yourself, when to call a pro, and how much each option costs.

Moss is not just cosmetic. It is destroying your shingles right now. Call 236-838-9577 for a free inspection and quote.

Why Moss Is Worse in Surrey Than Anywhere Else

Surrey has the perfect conditions for roof moss.

Factor 1: Annual rainfall – 1,200 to 1,600 mm
Moss needs moisture to grow. Surrey gets more rain than almost any city in Canada. Your roof is wet for weeks at a time.

Factor 2: Mature tree canopy
Fleetwood, Guildford, and South Surrey have dense tree cover. Shade keeps roofs damp longer. Sunlight kills moss. Shade grows it.

Factor 3: Mild winters
Moss grows year-round in Surrey. It does not die back in winter like in colder regions. It just keeps spreading.

Factor 4: Asphalt shingles
Moss roots grow under the edges of asphalt shingle tabs. The roots lift the shingles. Wind gets under lifted tabs. Wind tears shingles off.

See our guide on how long roofs last in Surrey’s climate for more detail on climate factors.

How Moss Destroys Your Roof – The Mechanism

Most homeowners think moss is cosmetic. It is not.

Stage 1: Moss spores land on your roof. They grow in damp, shaded areas. North-facing slopes are first.

Stage 2: Moss roots (called rhizoids) grow under the edges of shingle tabs. You cannot see them from the ground.

Stage 3: Roots lift the shingle tabs. The factory seal (adhesive) breaks. Shingles are now loose.

Stage 4: Winter freeze-thaw cycles expand the roots. Each freeze pushes the shingle higher. Each thaw lets water seep deeper.

Stage 5: Wind catches the lifted shingles. Shingles tear off or crack. Water enters the underlayment. Underlayment fails. Decking rots.

Stage 6: You have a leak. And moss is still growing.

A roof with heavy moss has 30-50 percent shorter lifespan than a moss-free roof. A 30-year shingle with untreated moss lasts 12-15 years in Surrey.

DIY Moss Removal – What You Can Safely Do Yourself

You can remove light moss yourself. You cannot safely remove thick, established moss yourself.

Safe DIY Method 1: Zinc or Copper Strips (Prevention)

Best for: Preventing moss before it starts. Does not remove existing moss.

How it works: Nail a strip of zinc or copper metal along the ridge of your roof. Rain carries microscopic metal particles down the roof. Moss cannot grow where metal particles land.

Cost: $50to$150 for materials (zinc strip from roofing supply store)

Installation: You need a ladder, safety harness, and ability to walk your roof. Do not attempt on steep slopes (over 6/12 pitch) or wet roofs.

Effectiveness: 70-80 percent effective on north slopes. Less effective on complex roofs with dormers and valleys.

Time to install: 1-2 hours for a simple roof.

Safe DIY Method 2: Spray-on Moss Killer (Light Moss Only)

Best for: Light moss coverage (less than 20 percent of roof surface, moss less than 1/4 inch thick).

Products that work (available at home improvement stores):

• Spray and Forget (zinc sulfate-based)

• Wet and Forget (same formula)

• Moss B Ware (copper sulfate-based)

What to do:

1. Choose a dry day with no rain forecast for 48 hours

2. Mix product according to instructions

3. Attach sprayer to garden hose (no ladder needed for many products)

4. Spray from ground or from ladder (do not walk the roof)

5. Wait 3-6 months for moss to die and fall off naturally

Cost: $30to$80 per bottle (covers 2,000-4,000 sq ft)

Effectiveness: 50-70 percent for light moss. Does not work on thick moss.

Time: 30 minutes to spray. 3-6 months to see results.

What to Avoid: Pressure Washers and Bleach

Never use a pressure washer on an asphalt shingle roof.

Here is what happens:

• 1,500+ PSI of water strips the protective granules off shingles

• Granules block UV rays. Without granules, shingles degrade in 2-3 years

• Water forces under shingle tabs. Underlayment gets soaked

• Your warranty is voided

We have replaced roofs that were 5-7 years old because homeowners pressure washed them. A $15,000roofruinedbya$50 pressure washer rental.

Never use bleach (sodium hypochlorite) on a roof. Bleach kills plants (your garden, your neighbor’s garden) and corrodes aluminum gutters and flashing.

Professional Moss Removal – What You Get

Professional moss removal is called “soft washing.” No pressure. No bleach. No damage.

Soft Washing Process

Step 1: Safety setup. Professional roofers use harnesses, ropes, and ladder stabilizers. They carry liability insurance and WCB coverage.

Step 2: Dry debris removal. Large moss clumps and leaves are removed by hand. No scraping – scraping damages shingles.

Step 3: Application of professional-grade biocide. Products like Bio-Shield or Spray and Forget Professional are applied. These are stronger than retail products but require training and safety equipment.

Step 4: Low-pressure rinse (if needed). 300-500 PSI (compared to 1,500-3,000 PSI for pressure washers). Just enough to move the product.

Step 5: Follow-up treatment (if moss is thick). Two applications spaced 4-6 weeks apart for heavy moss.

Step 6: Gutter cleaning. Dead moss and debris are flushed from gutters and downspouts.

Professional Moss Removal Cost – Surrey Pricing

These prices include biocide application and gutter flushing. Additional treatments (if moss returns within 12 months) are discounted or free depending on the contractor.

We offer professional roof cleaning service with soft washing only. No pressure. No damage. Free quote.

DIY vs Professional – Decision Matrix

Use this table to decide which option is right for your roof.

Decision Rule

If you have:

• Light moss (under 20% coverage)

• Single-story home

• Walkable roof slope

• Good shingle condition

• Comfortable on a ladder

Then DIY with zinc strips or spray-on moss killer is reasonable.

If you have:

• Medium or heavy moss (over 20% coverage)

• Two-story home

• Steep roof slope (over 6/12 pitch)

• Poor shingle condition

• Moss growing under shingle tabs (visible lifting)

• Any roof leaks

Then call a professional. Do not risk your safety or your roof.

Step-by-Step: How to Remove Moss Yourself (If You Qualify)

If you have light moss and meet the DIY criteria above, follow these steps.

Step 1: Choose a dry day with no rain forecast for 48 hours.

Step 2: Protect your landscaping. Cover shrubs and flower beds with tarps. Moss killer will not kill plants at low concentrations, but overspray can cause browning.

Step 3: Put on safety gear. Rubber gloves. Safety glasses. Long sleeves. Old shoes with good grip.

Step 4: Mix product according to instructions. Do not make it stronger. Stronger is not better and may damage shingles.

Step 5: Attach sprayer to garden hose. Use the “shrub and tree” setting (gentle cone spray). Do not use jet setting.

Step 6: Spray from a ladder or from ground. Do not walk the roof. Spray each slope starting at the ridge and working down.

Step 7: Do not rinse. Let product dry on the roof.

Step 8: Wait 3-6 months. Moss will turn brown, then black, then fall off. Do not scrape or brush dead moss. Rain will wash it off.

Step 9: Clean gutters after moss falls. Dead moss will collect in downspouts.

If this sounds like too much work or too risky, call a professional.

What to Look for in a Professional Moss Removal Company

Not all roof cleaners are equal. Here is what to ask before hiring.

Do you use soft washing or pressure washing?
If they say pressure washing, hang up and call someone else. Pressure washing destroys asphalt shingles.

Are you licensed and insured?
Ask for WCB certificate of clearance and liability insurance ($2 million minimum). Without insurance, you are liable if they fall off your roof.

Do you walk the roof or work from ladders?
Walking is safer for low-slope roofs. Ladders only for steep slopes. Both require safety harnesses.

What product do you use?
Professional-grade biocide (Bio-Shield, Spray and Forget Pro, Moss-Out). Not household bleach.

Do you offer a warranty?
6-12 months on moss re-growth is standard.

Do you clean gutters afterward?
Yes. Dead moss must be flushed from gutters.

We meet all these standards. Professional roof cleaning with soft washing only. Licensed, insured, WCB covered.

What Happens If You Do It Wrong

Here are real examples from Surrey homes.

Example 1: Pressure washer damage – Fleetwood (2023)
Homeowner: Pressure washed moss off 8-year-old roof. Shingles lost 50% of granules. Roof failed at year 12 instead of 22-25. Replacement cost: $16,000.Pressurewasherrental:$50. Lesson: Do not pressure wash.

Example 2: Fall from ladder – Newton (2022)
Homeowner: DIY moss removal on two-story home. Ladder slipped on wet grass. Broken wrist, cracked ribs, ambulance ride, 3 months off work. Roof: Still mossy. Lesson: Two-story roofs are not DIY.

Example 3: Bleach damage – South Surrey (2024)
Homeowner: Sprayed bleach solution on moss. Bleach ran into gutters, corroded aluminum gutter seams. Gutters leaked. Water damaged fascia board. Repair cost: $1,800.Bleach:$10. Lesson: Bleach destroys metal.

Example 4: Successful DIY – Cloverdale (2023)
Homeowner: Light moss on single-story bungalow. Used zinc sulfate spray from garden hose. No ladder. No roof walking. Moss died in 4 months. Cost: $45. Lesson: DIY works for light moss on simple, low roofs.

Preventing Moss After Removal

Once your roof is clean, keep it clean.

Install zinc or copper strips
$50to$150 in materials. Nail along the ridge. Rain carries moss-killing metal particles down the roof. Effective for 3-5 years.

Trim overhanging branches
More sunlight = less moss. Trim branches that shade your roof. Hire an arborist for large trees.

Clean gutters twice per year
Clogged gutters hold moisture against the roof edge. Clean gutters in spring and fall.

Annual roof inspection
Have a roofer walk your roof once per year. They will spot moss before it becomes a problem. Schedule a roof inspection annually.

Professional treatment every 2-3 years
Even with zinc strips, professional soft washing every 2-3 years keeps moss away.

FAQ

1. Is moss on my roof an emergency?

No, but do not ignore it. Light moss (under 20% coverage) can wait 3-6 months. Heavy moss (over 50% coverage, lifting shingles) should be treated within 1-2 months before winter freeze-thaw cycles cause damage.

2. Will moss removal damage my shingles?

Professional soft washing does not damage shingles. DIY with spray-on products does not damage shingles. Pressure washing damages shingles. Scraping or brushing damages shingles. Choose the right method.

3. How often should I remove moss from my roof in Surrey?

Every 2-3 years for most homes. Homes under heavy tree canopy (South Surrey, Fleetwood) may need annual treatment. Homes in full sun (newer subdivisions) may need treatment every 4-5 years.

4. Can I walk on my roof to remove moss?

Only if:

• Roof slope is under 6/12 (walkable without special equipment)

• Shingles are dry and not brittle

• You have proper footwear (soft rubber soles, not work boots)

• You have a safety harness anchored to a solid structure

If you answer no to any of these, do not walk your roof.

5. Does roof cleaning void my shingle warranty?

DIY pressure washing absolutely voids warranties. Professional soft washing does not. GAF, CertainTeed, and Owens Corning warranties specifically exclude damage from high-pressure washing. Soft washing (low pressure, chemical treatment) is allowed.

Your Next Step

Moss is destroying your roof right now. Every week you wait, the roots grow deeper. Every winter freeze pushes shingles higher. Every wind storm risks tearing off lifted tabs.

You have two choices:

Option 1: DIY for light moss on a single-story, walkable roof. Cost: $50to$150. Risk: Low if you follow safety rules.

Option 2: Call a professional for medium or heavy moss, steep roofs, or two-story homes. Cost: $300to$1,400. Risk: Zero for you. We carry insurance and WCB.

Call 236-838-9577 for professional moss removal. Soft washing only – no pressure damage. Free quote. We serve all Surrey neighborhoods: Fleetwood, Guildford, Newton, Cloverdale, South Surrey, Whalley, and North Surrey.

Imroofs – professional moss removal that protects your roof. No pressure. No damage. Just a clean, moss-free roof.