Louisiana is one of the hardest climates in the country on home exteriors. High humidity, 10+ months of heat, winter rain, and spring pollen create a perfect environment for algae, mildew, mold, and black streaks to take hold faster than anywhere else in the South.
Most homeowners wait until they can visibly see the damage — but by then, the algae has already been feeding on your shingles, the mildew has already penetrated your siding, and the concrete has already started to deteriorate beneath the surface staining.
This guide gives you the maintenance calendar professionals use to protect homes in this climate — broken down by season, by surface, and by what's at stake if you skip it.
Section 1
The Seasonal Hit List
What to prioritize each season — and why the timing matters in Louisiana specifically.
Spring
Feb – Apr: Pollen + algae bloom season
- 🌿House washing — pollen and winter grime coat siding and brick before summer heat bakes it in
- 🏠Roof inspection + soft wash — algae wakes up in warming temps; treat it before it spreads across shingles
- 🚗Driveway cleaning — winter rain leaves black streaks and moss on concrete; spring is the ideal cleaning window
- 🌧️Gutter flush — clear pollen, leaf debris, and winter buildup before spring rains start
Summer
May – Aug: Peak mold and mildew season
- 🔥Deck and fence wash — humidity accelerates wood mildew; clean before summer cookouts, then seal if bare wood
- 🌡️Concrete and pool deck — heat and organic material create slippery algae growth; safety hazard by July
- 🏡Spot-check siding — mildew travels fast in summer; catch new growth early before it stains permanently
Fall
Sep – Nov: Pre-winter protection window
- 🍂Full exterior wash — best time to reset the whole house before cold rain sets in
- 🏠Roof check — any algae left on shingles will expand with winter moisture; treat now or pay more in spring
- 🚿Gutter cleaning — critical before fall rain season; blocked gutters cause fascia rot and foundation seepage
- 🪵Deck recheck — if you didn't seal in spring, do it now before winter rain soaks bare wood
Winter
Dec – Jan: Maintenance + recovery
- 🌧️Post-storm concrete wash — Louisiana winters bring heavy rain and mud; driveways and sidewalks take a beating
- 🔍Visual roof scan after storms — check for lifted shingles, moss patches, or algae restarting in wet conditions
- 📋Plan your spring wash — book early; spring is the busiest season and good crews fill up fast
Section 2
Soft Wash vs. Pressure Wash — Why It Matters
Using the wrong method on the wrong surface causes real damage. Here's the right tool for each job.
Roof / Shingles
Soft Wash Only
Why Soft Wash
High pressure strips the protective granules off asphalt shingles and voids most manufacturer warranties. Soft wash uses low pressure + an algaecide solution to kill algae at the root without damage.
What Happens if You Skip It
Algae (Gloeocapsa magma) feeds on the limestone filler in shingles. Left untreated for 2–3 years, it reduces shingle lifespan by up to 10 years.
Vinyl / Fiber Cement Siding
Soft Wash
Why Soft Wash
High pressure forces water behind panels, leading to moisture intrusion and mold growth inside your walls. Soft wash removes mildew, algae, and oxidation safely.
What Happens if You Skip It
Mildew staining becomes permanent after 1–2 seasons. Oxidation on vinyl creates a chalky film that makes the home look aged even after cleaning.
Concrete Driveway
Pressure Wash
Why Pressure Wash
Concrete is dense enough to handle high pressure. A hot-water pressure wash removes oil stains, black algae, and embedded grime that surface-level cleaning misses entirely.
What Happens if You Skip It
Algae growth makes concrete dangerously slippery. Oil stains etch deeper over time and become nearly impossible to fully remove after 2+ years.
Wood Deck / Fence
Low Pressure + Treatment
Why Low Pressure
High pressure raises wood grain and can split older boards. Low pressure combined with a wood-safe cleaning solution lifts mildew and gray weathering without damaging the surface.
What Happens if You Skip It
Mildew penetrates bare or unsealed wood within one Louisiana summer. After 2–3 seasons, wood rot sets in and full board replacement becomes necessary.
Brick / Stucco
Low Pressure
Why Low Pressure
High pressure erodes mortar joints on brick and can crack or pit stucco surfaces. Low pressure with appropriate cleaners removes efflorescence and algae without structural damage.
What Happens if You Skip It
Efflorescence (white mineral deposits) and algae staining are cosmetic at first, but moisture trapped in deteriorating mortar leads to structural issues over time.
Section 3
The Real Cost of Waiting
This is how a $250 cleaning turns into a $12,000 repair. It happens slowly — then all at once.
1
Algae appears on roof shingles
You notice dark streaks. It looks cosmetic. It's not — Gloeocapsa magma is already digesting the limestone filler in your shingles. Cost to treat now: $275–$400.
↓
2
Granule loss accelerates (Year 1–2)
Algae feeds, granules loosen, shingles lose their UV protection and waterproofing layer. Your roof is aging 2–3x faster than it should. The streaks spread. Cost to treat: $400–$600.
↓
3
Moisture intrusion begins (Year 2–4)
Compromised shingles let water in. Decking under the shingles starts to rot. You may not see it, but your attic is collecting moisture with every rain. Cost: decking repairs, $1,500–$4,000.
↓
4
Full roof replacement (Year 4–6)
What should have lasted 25+ years is now failing at 15. Full replacement runs $8,000–$15,000 on an average Louisiana home. The algae that started it all cost $275 to treat. Cost: $8,000–$15,000.
⚠️
The same pattern applies to every surface on your home. Siding mildew leads to moisture intrusion. Concrete algae leads to surface deterioration. Wood deck mildew leads to rot. The cleaning is always cheaper than the repair — by an order of magnitude.
Section 4
Visual Inspection Checklist
Walk your property and check each surface against this list. If you see any of these, it's time to schedule a cleaning.
Roof / Shingles
- Dark streaks or black staining running down the slope
- Green or gray patches near the ridge or valleys
- Visible moss or lichen clumps on shingles
- Granules collecting in gutters or downspout discharge
- Shingles appear faded or uneven in color
Siding / Exterior Walls
- Green or black streaks below windows or gutters
- Chalky white residue on vinyl (oxidation)
- Dark mildew spots on north-facing or shaded walls
- Staining around AC condensate lines or hose bibs
- General dullness or color fading across panels
Driveway / Concrete
- Black or green algae patches (especially in shaded areas)
- Oil stains that have spread or darkened over time
- Gray-to-black discoloration along expansion joints
- Slippery surface when wet (algae growth)
- Rust stains from irrigation or vehicle leaks
Deck / Fence
- Gray weathering or black mildew on wood grain
- Green algae on horizontal surfaces and rails
- Wood feels soft or spongy in spots (early rot)
- Stain or sealant peeling or flaking
- Dark discoloration at board ends or post bases
Gutters
- Plants growing from gutters (debris accumulation)
- Water spilling over edges during rain (blockage)
- Black staining on exterior gutter face (overflow)
- Sagging sections from debris weight
- Visible debris at downspout discharge area
Brick / Stucco
- White powdery deposits on brick faces (efflorescence)
- Green or black algae in mortar joints
- Stucco discoloration from moisture tracking
- Dark streaks below windowsills or roof line
- Crumbling or recessed mortar between bricks
Ready to get your home on a maintenance schedule?
We serve Prairieville, Gonzales, Baton Rouge, and all of Ascension Parish. Free estimates, always. Most jobs scheduled within the week.
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