What Should You Expect From a Home Inspection in the Seattle Area? Sewer Scopes, Moss, Crawl Spaces, and Oil Tanks

What should I expect from a home inspection in the Seattle area?

A general inspection covers the roof, structure, foundation, crawl space or basement, electrical, plumbing, heating, and major systems. In the Pacific Northwest, buyers often add a sewer scope, and for older homes a heating oil tank sweep. Expect your inspector to look closely at moisture, drainage, and ventilation, because our wet climate shows up in almost every house.

I am Cheryl Dillon, a real estate broker serving Edmonds, Bothell, and surrounding South Snohomish County, North King County, and Eastside communities. Every week I walk buyers through inspection day, the day a house stops being listing photos and becomes a real structure with a real history.

I have lived in the Seattle area for over 40 years. The same rain that keeps our region green creates a specific set of things every buyer should check. Inspection findings are information, and information is protection. Nearly every home has something on the report.

Do I need a sewer scope when buying a home in Seattle?

It is strongly recommended, especially for older homes and homes with mature trees nearby. A sewer scope is a video camera inspection of the side sewer, the underground pipe carrying wastewater from the home to the public main. It is a separate service from a general inspection and looks at something no one can see from the surface.

Who is responsible for the side sewer in Seattle?

According to Seattle Public Utilities, the property owner owns the side sewer all the way to the public sewer pipe, which is often under the street. A problem under the sidewalk or even the street can be the homeowner's responsibility. Some homes share a side sewer with a neighbor, so repairs may need coordination. Other cities have their own rules, so confirm ownership for the specific address.

What does it cost? Seattle Public Utilities says a sewer video inspection generally costs about $230 to $845, depending on the pipe's condition. SPU also notes that trenchless repair methods such as relining or pipe bursting can cost roughly $100 to $170 per foot, while excavation under a street can cost substantially more.

What does a scope commonly find?

Old clay and concrete pipes, tree roots in joints, sagging sections called bellies, cracks, and offsets. Seattle Public Utilities recommends inspecting a side sewer at least every 8 to 10 years, and every 2 to 3 years when large trees or shrubs grow near the line.

Is moss on a roof a problem?

Light moss is common and usually a maintenance item. Heavy moss holds moisture against shingles, can lift shingle edges, and can clog gutters and valleys, which can shorten a roof's life. Ask your inspector:

• What is the roof's approximate age and remaining life?
• Is there damage under the moss, such as lifted or deteriorated shingles?
• Are gutters, valleys, and downspouts clear and draining?
• Would a roofing contractor evaluation be worthwhile?

For an older roof near the end of its life, heavy moss can signal a replacement budget, which is a meaningful negotiation point.

What crawl space issues are common in the Pacific Northwest?

Many homes here sit on crawl spaces, and that is where moisture shows first. Common findings:

• Standing water or signs of past water after heavy rain.
• A missing, torn, or displaced vapor barrier (the plastic sheeting that blocks ground moisture).
• Damp or damaged insulation under the floor.
• Wood rot on sill plates, joists, or posts.
• Rodent evidence, usually handled through exclusion and cleanup.
• Wood destroying insects such as carpenter ants and dampwood termites.

A wet crawl space can affect air quality, invite pests, and lead to structural repairs if ignored, but many issues are very fixable. Finding the source, whether gutters, grading, or groundwater, is the key to the right solution.

What should I know about buried heating oil tanks in Washington?

Many older homes in Seattle, Shoreline, Edmonds, and other established areas were once heated with oil, and some left an old tank buried in the yard. Clues include a fill or vent pipe near the foundation, capped copper lines in the basement or crawl space, or an older furnace setup. Buyers often order a tank sweep, and soil testing if a tank is found.

Washington's Pollution Liability Insurance Agency has transitioned the former Heating Oil Insurance Program into newer assistance programs. PLIA's Heating Oil Loan and Grant guidance states that awards can be up to $75,000 for a single heating oil tank, subject to eligibility, available funding, and program rules. PLIA's current website also directs property owners to its Financial Assurance Program and online application process. Because program details can change, buyers and owners should check PLIA's current guidance before relying on a specific funding amount or application timeline. PLIA can also provide technical review that may result in a No Further Action opinion when cleanup meets state requirements. If a tank is present, ask for records of decommissioning, removal, soil testing, or cleanup, and obtain a specialist evaluation when records are incomplete.

What other issues are common in older Seattle area homes?

• Electrical: knob and tube wiring, outdated panels, or ungrounded outlets. An electrician's evaluation helps with insurance and safety questions.
• Plumbing: galvanized steel supply lines, and polybutylene piping in some homes from the late 1970s through the mid 1990s.
• Drainage and grading: soil sloping toward the home, clogged footing drains, or downspouts emptying against the foundation.
• Slopes and steep lots: parts of Seattle, Edmonds, and Mukilteo include hillside and bluff properties. Some cities designate steep slopes as environmentally critical areas that can affect future projects. A geotechnical evaluation brings clarity.
• Indoor moisture: bathroom, kitchen, and attic ventilation matter in a damp climate, since trapped moisture can lead to mold.

How does the seller's disclosure fit with the inspection?

In Washington, sellers of most residential property provide a disclosure statement, commonly called Form 17, covering water intrusion, the sewer system, heating, and known defects. Read it alongside the inspection report. When the two tell different stories, ask good questions.

What happens if the inspection finds a problem?

Finding items is normal. What you do next is strategy:

1. Separate routine from significant. Worn caulking is routine. A failing side sewer, active roof leak, or oil tank leak is significant.
2. Bring in specialists for big items. A sewer contractor, roofer, structural engineer, or tank specialist gives estimates that ground your negotiation.
3. Choose the right request: a repair, a credit toward closing costs, a price adjustment, or in some cases walking away within your inspection timeline.
4. Mind your deadlines. Washington purchase agreements set specific timelines for inspections and responses. Schedule inspections quickly so you have time for specialists.

Current Northwest MLS data shows substantially more inventory than a year ago, giving many buyers more choice and, in some transactions, more room to negotiate inspection findings than during the most competitive pandemic era markets. Leverage still varies by neighborhood, price point, property condition, and the strength of competing offers.

What are the most common buyer mistakes at inspection?

• Skipping the sewer scope on an older home with mature trees.
• Scheduling the scope late, leaving no time for a contractor bid.
• Treating every item as a crisis, or none as a concern.
• Not reading Form 17 next to the inspection report.
• Missing the inspection deadline in the purchase agreement.

A real inspection scenario

One inspection I will never forget involved first time buyers purchasing a home that appeared to have a brand new roof. During the inspection, we discovered wood destroying water beetles had eaten through an entire rafter and damaged part of the side of the house. The elderly seller had paid to have the roof replaced only a few years earlier and had no idea the damage was there. When we tried to reach the roofing company, we learned it was essentially a fly by night operation and could not be reached. The listing agent arranged to meet with the seller in a public restaurant to carefully explain what the inspection had uncovered. It was difficult news because the repairs meant the seller would lose a substantial amount of her equity. She ultimately completed the necessary repairs, and my buyers were able to move forward with the purchase. That experience is one of the reasons I tell buyers that an inspection is not about finding a perfect house. It is about discovering what you are actually buying before you own it.

I am Cheryl Dillon, a real estate broker serving Edmonds, Bothell, and surrounding South Snohomish County, North King County, and Eastside communities. I help buyers read inspection reports in context, so they know what is routine and what is worth negotiating.

Frequently Asked Questions

Who owns the side sewer in Seattle? The property owner, up to the public sewer pipe, per Seattle Public Utilities.

How much does a sewer scope cost? Seattle Public Utilities publishes a general range of about $230 to $845 for a sewer video inspection, depending on the pipe's condition.

Is a little moss on my roof a problem? Usually a maintenance item. Heavy moss can shorten roof life.

How do I find a buried oil tank? A specialist tank sweep, plus clues like fill and vent pipes.

What if the inspection finds something big? Within your inspection timeline you can request a repair, credit, or price change, or decide the home is not the right fit.

Ready to buy with confidence?

I am Cheryl Dillon, a real estate broker serving Edmonds, Bothell, and surrounding South Snohomish County, North King County, and Eastside communities. Whether you are buying your first home, relocating, or buying an older home with character, I would love to help you move forward with clarity and protection at every step.

425.954.5622 | Cheryl@CherylDillonRealEstate.com | CherylDillonRealEstate.com

I am Cheryl Dillon a licensed REALTOR® in the state of Washington with eXp Realty.