Resources

Stain & Problem Library

Explore common exterior staining and surface issues, what causes them, how Yellow Wash cleans them, and how you can help prevent them.

1 Common Issue

Organic Growth on Siding

Organic growth on siding

Green streaks, algae, mildew, and organic films on shaded siding.

Organic Growth on Siding

What causes it

Shade, moisture, nearby trees, and organic material allow algae and mildew to grow.

How we clean it

We use a controlled soft wash process to treat the growth at the source.

How to prevent it

Improve sunlight, reduce moisture, trim vegetation, and keep siding cleaned regularly.

2 Specialty Issue

Artillery Fungus on Siding

Artillery fungus on siding

Small black specks that can bond tightly to siding and trim.

Artillery Fungus on Siding

What causes it

Fungus from mulch releases tiny black spores that stick to nearby surfaces.

How we clean it

Soft washing can help treat the area, but bonded specks may not fully release.

How to prevent it

Replace old mulch, improve airflow, and avoid placing mulch close to siding.

3 Common Issue

Lichen on Siding

Lichen on siding

Crusty attached growth that can discolor exterior surfaces.

Lichen on Siding

What causes it

Lichen grows where moisture, shade, and organic buildup sit for long periods.

How we clean it

We use a careful soft wash approach to treat and loosen the growth safely.

How to prevent it

Keep surfaces clean, reduce dampness, and trim vegetation near the home.

4 Common Issue

Black Streaks on Gutters

Oxidation on gutter

Dark vertical marks often called tiger striping or gutter oxidation.

Black Streaks on Gutters

What it is

Oxidized gutter coating collects runoff, dirt, and pollutants, creating black streaks.

How we clean it

Gutter brightening uses specialty cleaning methods beyond a standard house wash.

How to prevent it

Regular exterior cleaning helps reduce buildup, but oxidation may return over time.

5 Roof Issue

Moss on Roofs

Moss on roof

Common in Halifax weather, shaded roof sections, and damp areas.

Moss on Roofs

Why it happens

Moisture, shade, tree coverage, and debris create ideal moss growth conditions.

Why pressure is not the answer

Pressure washing can damage shingles, loosen granules, and shorten roof life.

How we clean it

We use low-pressure roof treatment designed to kill moss at the root.

6 Concrete Issue

Oil Stains on Driveways

Oil stain on driveway

Dark spots from vehicle fluids, leaks, and deep-set driveway staining.

Oil Stains on Driveways

What can improve

Fresh stains often improve significantly with the right degreasing process.

What may not disappear fully

Deep stains can absorb into concrete and may fade without vanishing completely.

Best next step

Professional assessment gives the most realistic expectation before cleaning.

7 Specialty Issue

Rust Stains

Rust stain on driveway

Orange or brown staining from metal, irrigation, or mineral deposits.

Rust Stains

Common causes

Metal furniture, irrigation water, fertilizer, tools, and runoff can create rust stains.

How we clean it

Rust usually requires specialty treatment rather than standard pressure washing.

What to expect

Results depend on the surface, stain age, and how deeply it has penetrated.

8 Surface Issue

Oxidation on Siding

Oxidation on siding

Chalky, dull, faded, or uneven siding appearance caused by sun exposure.

Oxidation on Siding

What causes it

UV exposure, age, and weathering break down the surface coating over time.

How it looks

It may look chalky, faded, streaky, or leave a powdery residue when touched.

How to prevent it

Routine gentle cleaning helps, but aged siding may still oxidize naturally.

9 Surface Issue

Oxidation on Window & Door Frames

Oxidation on door frame

Faded, chalky frames that lose their original finish over time.

Oxidation on Frames

What causes it

Sun, age, weather, and worn coatings can create chalky frame surfaces.

How it looks

Frames may appear dull, faded, powdery, streaked, or uneven in color.

Important note

Oxidation may need specialty restoration and is not always removed by washing.

10 Specialty Issue

Pigeon Waste & Bird Droppings

Pigeon droppings

Messy, acidic, unpleasant, and potentially harmful buildup on surfaces.

Pigeon Waste & Bird Droppings

Why it matters

Bird waste can be acidic, unsanitary, slippery, and damaging to surfaces.

How we clean it

We remove buildup carefully and use appropriate cleaning methods for the area.

Best next step

Heavy buildup should be assessed before cleaning for access and safety planning.

11 Common Issue

Cobwebs & Spider Spots

Cobwebs on exterior siding

Webs, dust, spider marks, and debris around exterior corners and overhangs.

Cobwebs & Spider Spots

What causes it

Protected corners, lights, soffits, and shaded areas attract insects and webs.

How we clean it

House washing helps remove exterior webs, dirt, and light surface buildup.

How to prevent it

Keep exterior lights and corners maintained and schedule routine cleaning.

Not sure what you’re dealing with?

We’re here to help. Get a professional assessment and a plan that’s right for your property.