Middle Fork Exteriors · Snoqualmie Valley

Your Home's
Honest Cleaning Guide

We believe you should understand exactly what we're doing to your home, why, what it costs, and what to realistically expect. This guide gives you the real picture — no upsell, no fluff.

Website
middleforkexteriors.com
Phone
(425) 569-4011
A note on honesty: Exterior cleaning is a service where a lot of contractors oversell results or use the wrong technique for the wrong surface. We'd rather tell you what each approach actually does — including its limits, risks, and realistic lifespan — so you can make an informed decision. Some jobs are straightforward. Some require tradeoffs. We'll be upfront about both.
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Roof Cleaning

Asphalt shingles · Cedar shake · Tile · Metal — each surface has a different right answer

Soft Wash (Chemical Cleaning)
Best for Asphalt Most Common
Effectiveness
Excellent
Results Last
1–3 yrs*
Shingle Risk
Very Low
Typical Cost
$$
Low-pressure sodium hypochlorite (diluted bleach) and a biodegradable surfactant are applied and left to dwell. The chemistry kills moss, algae, and lichen at the root — not just scrubbing the surface. This is the method endorsed by the Asphalt Roofing Manufacturers Association (ARMA) and the right tool for 90% of residential roofs.
What to expect: Your roof won't look showroom-new immediately. Organic growth browns and rinses off over a few weeks. Results are lasting because the biology is killed, not just washed away. Many homeowners notice significant improvement within the first rainfall.
*PNW reality check: National industry claims of "3–5 year results" are often based on drier climates. In the Snoqualmie Valley — with 55+ inches of rain per year and heavy tree canopy — plan on 1–3 years depending on your roof's sun exposure. North-facing and heavily shaded roofs trend toward the shorter end.
Honest limitation: Diluted bleach does contact surrounding vegetation. We pre-wet all landscaping and rinse afterward — this protects plants in the vast majority of cases. If you have highly sensitive ornamental plants directly adjacent to the roof line, let us know in advance.
Cedar Shake — Specialized Low-Concentration Soft Wash
Cedar Only Expertise Required
Effectiveness
Good
Results Last
1–2 yrs
Wood Risk (correct technique)
Low–Moderate
Typical Cost
$$$
Cedar is porous, naturally oily, and does not tolerate high chemical concentrations or any pressure. We use a significantly reduced bleach concentration (about half that of an asphalt job), longer dwell time, and low-pressure application only — followed by a thorough rinse. This removes biological growth without stripping the wood's natural oils or degrading the shake fibers.
Honest limitation: Cedar requires more maintenance than asphalt. Biological regrowth returns faster because wood retains moisture longer. We recommend pairing cleaning with a follow-up moss inhibitor treatment, and budgeting for cleaning every 1–2 years rather than every 3–4. Most contractors decline cedar or use the wrong technique. We specialize in it.
What to watch for: If your cedar shakes are severely weathered, cracked, or cupped, cleaning will not fix structural deterioration. We'll flag any concerns during the estimate walk so you're not surprised.
High-Pressure Washing on Roofs
We Don't Offer This
High-pressure washing removes granules from asphalt shingles — the granules that protect the asphalt mat from UV radiation. One pressure wash can age a roof by 5–10 years. On cedar shake, it forces water into the wood grain and accelerates splitting and rot. We won't do it, and we'd recommend against anyone who offers it for roof surfaces.
Why we're telling you this: Pressure washing is visually satisfying — surfaces look clean immediately. It's also faster and easier for contractors. The damage shows up later, on your dime. We'd rather lose a job than damage your roof.
Moss Inhibitor Treatment (Preventive Add-On)
Extends Results
Prevention
High
Protection
12–18 months
Environmental Risk
Moderate
Add-On Cost
$–$$
Applied after cleaning, moss inhibitor granules or liquid (typically zinc-based) prevent biological regrowth. This is especially valuable in the Snoqualmie Valley where heavy tree cover and rainfall accelerate moss cycles.
Environmental note — important in our area: Zinc sulfate is effective but is toxic to aquatic life at low concentrations. We take this seriously given our proximity to the Snoqualmie River watershed. For properties near waterways, streams, or drainage channels, we use sodium percarbonate — a lower-risk alternative that's still highly effective. We'll tell you which we're using and why.
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Driveway & Concrete Cleaning

Sealed concrete · Unsealed concrete · Pavers · Asphalt — different surfaces, different approaches

Pressure Washing with Surface Cleaner
Best for Most Driveways Standard Approach
Effectiveness
Excellent
Cycle
Annual recommended
Surface Risk
Very Low
Typical Cost
$$
A rotating 20-inch surface cleaner disc applies even pressure across the surface, removing algae, tire marks, oil residue, and biological staining. This is dramatically more even than a wand — no "zebra stripes" or uneven cleaning patterns. We run it at appropriate pressure for the surface type.
Sealed vs. unsealed: Sealed concrete cleans up beautifully and tends to stay clean longer — the sealer prevents surface penetration by oils and biological growth. Unsealed concrete absorbs more contaminants and will re-dirty faster; cleaning is still effective but the cycle is shorter.
What we can't fix: Deep oil stains that have been sitting for years may be permanently absorbed into unsealed concrete. We'll tell you at the estimate if we think results will be limited. No contractor can promise a stain-free finish on old, deeply penetrated oil.
Pre-Treatment with Biodegradable Degreaser
For Oil & Grease Stains
Oil Stain Removal
Good–Excellent
Add-On Time
+30–45 min dwell
Surface Risk
Low
Add-On Cost
$
Phosphate-free, biodegradable degreaser is applied to oil and grease stains before pressure washing. It breaks up petroleum bonds in the concrete surface. Results depend heavily on how old and deep the stain is — we'll assess during the estimate.
Honest expectation-setting: A 6-month-old oil stain from a parked car will respond very well. A 10-year-old stain from a vehicle that sat for years may only improve partially. We'll be straight with you about what's likely before you pay for it.
Asphalt Driveways
Different Rules Apply
Asphalt requires lower pressure than concrete — typically 1,000–1,500 PSI versus 2,500–3,000 PSI for concrete. High pressure strips the binding oils from asphalt, accelerating cracking and deterioration. We adjust accordingly. Asphalt also should not have chemical degreasers applied — petroleum-based products can soften the surface.
Our recommendation: For asphalt, low-pressure rinsing and a surface cleaner at reduced PSI removes most biological growth and light staining effectively. For oil stains on asphalt, results are more limited than on concrete.
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House Washing & Siding

Vinyl · Hardie board · Cedar · Painted wood — siding is the face of your home and different materials need different care

Soft Wash House Wash (Vinyl / Hardie / Painted Wood)
Recommended Low-Pressure
Effectiveness
Excellent
Results Last
1–2 years
Siding Risk
Very Low
Typical Cost
$$
Diluted sodium hypochlorite and surfactant are applied at low pressure, dwelled briefly, and rinsed — removing mold, mildew, algae, and oxidation staining from siding. This is safe for vinyl, Hardie board, and most painted wood surfaces and won't drive water behind panels the way high pressure can.
Oxidation on vinyl: That chalky, faded look on older vinyl? Soft washing removes the oxidized layer and restores a cleaner appearance. It won't change the color of the vinyl if it has genuinely faded over decades — but the difference is typically dramatic.
Painted wood caution: We assess paint condition during the estimate. Paint that is already chipping or peeling may not hold up well to any cleaning — the water and chemistry can accelerate what's already failing. We'll flag this before starting so you can decide.
Natural Cedar Siding
Specialty Service
Natural cedar siding follows the same principles as cedar shake roofing — lower chemical concentration, no pressure, thorough rinse. Cedar siding is especially sensitive because it's more likely to be stained, weathered, or have adjacent trim and windows. We adjust our approach based on what we find on site.
After cleaning: Freshly cleaned cedar is an ideal surface for oil-based stain or sealant application. If you're planning to refinish your cedar siding, cleaning first gives the stain the best possible surface to adhere to. We're happy to coordinate timing with your painting or staining contractor.
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Deck Cleaning

Treated lumber · Cedar · Composite — decks need careful hands because the wood is close to occupant level and often near landscaping

Soft Wash + Wood Brightener (Best Results)
Full Treatment Recommended
Biological Removal
Excellent
Wood Color
Restored to natural tone
Wood Risk
Low
Typical Cost
$$–$$$
Step one: a diluted bleach solution removes mold, mildew, and green/black biological staining. Step two: an oxalic acid wood brightener neutralizes the tannin staining and iron oxidation (that gray-brown color on weathered wood), restoring the wood's natural tone. The combination is far more effective than either step alone.
Pre-stain timing: If you're planning to stain or seal your deck, this two-step clean is the best possible preparation. A clean, brightened surface accepts stain more evenly and holds it significantly longer. We recommend allowing 48–72 hours of dry time before staining.
Kids and pets: Keep children and pets off the deck for at least 2 hours after the final rinse and until the surface is fully dry. Pets that lick their paws after walking on freshly treated wood can experience GI irritation. We'll remind you of this before we leave.
Composite Decking (Trex, TimberTech, etc.)
Different Protocol
Cleaning Result
Very Good
Pressure Limit
Max 1,500 PSI
Surface Risk (correct technique)
Low
Typical Cost
$$
Composite decking must not be cleaned with high pressure — it can raise the surface grain and create a fuzzy texture that traps more dirt going forward. We use a low-pressure soft wash approach with composite-safe cleaners. Wood brightener (oxalic acid) is not used on composite — it's wood-specific.
Check your warranty: Many composite deck manufacturers specify approved cleaning methods in their warranty terms. We follow manufacturer guidelines. If you're unsure, check your deck's documentation or let us know the brand and we'll verify.
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Other Surfaces & Services

Gutters · Fences · Sidewalks · Retaining walls — we handle these often as add-ons to larger jobs

Gutter Cleaning & Flush
High Value
Physical removal of debris from gutters and a water flush to clear downspouts. We can also hand-brush the exterior face of gutters if they have significant staining or "tiger striping" (black vertical streaks from overflow). Physical gutter cleaning has zero chemical use and no surface risk. It's one of the highest-impact jobs for the money because clogged gutters cause foundation damage, siding rot, and roof edge failure over time.
Bundled with roof wash: Combining gutter cleaning with a roof wash makes practical sense — we're already set up on the roof. Bundled pricing reflects this.
Fences (Wood & Vinyl)
Common Add-On
Wood fences respond similarly to decks — soft wash removes biological growth, and brightener can restore color to weathered fence boards. Vinyl fencing is typically the simplest cleaning job we do: low-pressure wash and rinse. Results are very good and the job is usually fast.
Wood fence timing: Like decks, freshly cleaned wood fence is the ideal time to apply stain or sealant if you're planning to do so. Protect your investment.
Sidewalks, Walkways & Retaining Walls
Common Add-On
Same approach as driveway cleaning — surface cleaner at appropriate pressure for the material. Retaining walls, especially textured concrete block or natural stone, may require lower pressure and a soft wash application to avoid etching the surface or dislodging mortar. We assess the material before we start.
Pavers note: High-pressure cleaning can dislodge the polymeric sand between paver joints. We reduce pressure and angle accordingly. If the sand is already badly degraded, that's a separate repair — we'll point it out so you can plan ahead.

At-a-Glance: What to Expect from Each Service

Service Method Typical Result Results Duration Relative Cost Best Paired With
Asphalt Roof Wash Soft wash (SH + surfactant) Excellent; kills growth at root 1–3 years (varies by shade & exposure) $$ Gutter clean + moss inhibitor
Cedar Shake Roof Low-concentration soft wash Good; requires maintenance plan 1–2 years $$$ Moss inhibitor (low-zinc or percarbonate)
House Wash (vinyl/hardie) Soft wash Excellent; dramatic curb appeal improvement 1–2 years $$ Driveway clean for full-property refresh
Driveway / Concrete Surface cleaner + optional degreaser Excellent for biological; good–excellent for oil stains 1–2 years $$ House wash for same-day bundle pricing
Deck (wood) Soft wash + oxalic brightener Excellent; restores natural wood tone 1–2 years or until re-stain $$–$$$ Professional staining 48–72 hrs later
Deck (composite) Low-pressure soft wash Very good; removes biological growth 1–2 years $$ Annual maintenance plan
Gutter Cleaning Physical removal + water flush Complete debris removal; clear flow 6–12 months (tree-heavy sites) $ Roof wash or annual service
Moss Inhibitor Granular or liquid application High prevention of regrowth 12–18 months $–$$ Roof wash (always applied after, not before)

Not Sure What You Need? Start Here.

Moss on the roof, dark streaks on siding
House wash + roof wash bundle. Most impactful combination for curb appeal and home protection.
Oil stains or heavy discoloration on driveway
Driveway clean with degreaser pre-treatment. We'll assess stain age and set honest expectations during the estimate.
Deck that looks gray and weathered
Soft wash + brightener, ideally before you plan to re-stain. The two-step process makes a remarkable visible difference.
Gutters overflowing, water marks on siding
Gutter clean first, then house wash. The gutters cause the siding marks — fix the cause before cleaning the symptom.
Cedar shake roof — other contractors said no
We specialize in cedar. Most contractors decline it or use the wrong technique. Cedar is a different job, done right.
Property near the river or a creek
We're familiar with the watershed. We adjust chemical choices and containment practices for waterway-adjacent properties — ask us about it.
Middle Fork Exteriors Snoqualmie Valley Pressure Wash LLC
middleforkexteriors.com
[email pro