Why Washington Buyers Should Never Skip a Sewer Scope (2025 Guide)

If you’re buying a home in Washington—especially in Pierce, King, or Thurston County—a sewer scope is one of the most important inspections you can do.

It’s quick.
It’s inexpensive.
And it can save you from thousands of dollars in unexpected repairs.

Whether you're buying your first home, relocating to JBLM, or moving up to a home with more space, skipping the sewer scope is one of the most costly mistakes a Washington buyer can make.

This guide explains why.

1. Washington Has Older Sewer Lines Than You Think

Many homes in Tacoma, Puyallup, Lakewood, Olympia, and older surrounding areas were built decades ago. Their sewer lines may be:

• Clay

• Cast iron

• Orangeburg

• Concrete

• PVC (in newer homes)

Older materials often crack, collapse, corrode, or separate over time—especially with Washington’s soil conditions, root growth, and rainfall.

A sewer scope tells you:

• The material

• The age

• The condition

• Whether repairs are needed

• Whether replacement is likely soon

You cannot see this from a standard home inspection.

2. Tree Roots Are a Huge Issue in Washington

Our state is known for big trees—and big tree roots.
Roots naturally grow toward moisture and heat, and sewer lines provide both.

A sewer scope can identify:

• Root intrusion

• Cracked pipes

• Blockages

• Separated joints

• Collapsed sections

• Long-term damage

Most buyers never know there’s an issue until sewage backs up into the home—and by then, repairs are expensive.

This ties into the larger picture of what inspectors look for in Washington homes:

WA Inspection Red Flags Buyers Should Never Ignore (2025 Guide)
 

3. Sewer Repairs Are Extremely Expensive in WA

Repair and replacement costs vary depending on:

• Depth of line

• Location of the issue

• Whether the line runs under the driveway or street

• Material needed

• City permit requirements

Typical costs in Washington:

• Small repair: $2,500–$7,500

• Major repair: $8,000–$15,000

• Full line replacement: $15,000–$35,000

• Under the street replacement: $25,000–$60,000+

Spending $250–$350 on a sewer scope could save you tens of thousands.

4. Sewer Issues Don’t Show Up in a Standard Home Inspection

A general inspector cannot:

• Scope the sewer

• Diagnose sewer line materials

• Identify underground blockages

• Confirm breaks or root intrusion

Only a sewer contractor or inspector with a camera can evaluate the line properly.

This is why sewer scopes are always recommended in Washington—even for newer homes.

5. Many Washington Homes Have Sewer Lines That Run Through Neighbors’ Yards or the Street

Sewer lines don’t always run straight from your home to the city main.
In many WA neighborhoods—especially in older Tacoma and Pierce County areas—sewer lines may run:

• Under your neighbor’s driveway

• Across multiple yards

• Beneath the street

• Down a shared easement

This matters because:

• Repairs may require neighbor access

• Permits may take longer

• Costs can increase significantly

• Cities may have additional requirements

You need to know exactly where your line is and what it runs under.

6. Many Repairs Can Be Negotiated — But Only If You Scope the Line

Most WA buyers don’t realize how powerful a sewer scope is during negotiation.

If issues are discovered, buyers can often negotiate:

• Repair credits

• Line replacement credits

• Price reductions

• Seller-paid repairs

This guide breaks down how repair credits work and how buyers benefit from them:

How Repair Credits Work in Washington (2025 Buyer & Seller Guide)

Without a sewer scope, you lose this entire negotiation opportunity.

7. Sewer Line Problems Are Common in Pierce County

If you’re buying in Pierce County, especially Tacoma, University Place, Steilacoom, Fircrest, or older Puyallup, sewer scopes are not optional—they're essential.

Common findings include:

• Cast iron corrosion

• Root intrusion

• Offsets and separations

• Crushed or bellied lines

• Blockages from older materials

• Line collapse

This guide offers more insight into inspection concerns common in the area:

Common Inspection Problems in Pierce County (And How Buyers & Sellers Can Handle Them)
 

8. Sewer Scopes Are Quick, Easy & Affordable

Most sewer scopes:

• Take 20–45 minutes

• Cost between $250–$350

• Provide a full video

• Provide a written report

• Give you peace of mind

They’re one of the simplest inspections you can perform — and one with the biggest financial impact.

9. Problems Found Early Are Cheaper to Fix

A small repair today might cost:

• $2,000 now

• But $10,000 later if ignored

A sewer scope helps you:

• Identify issues early

• Understand immediate vs. long-term repairs

• Avoid emergency backups

• Plan financially for future maintenance

10. WA Buyers Should Never Waive a Sewer Scope in a Competitive Market

Even in a multiple-offer situation, most buyers can still:

• Complete the sewer scope before offer review

• Conduct the scope during inspection contingency

• Submit an offer with a sewer scope already completed

• Make a smart, safe decision without risking their finances

If you’re considering waiving certain contingencies, this guide explains how to navigate the process after inspection:

WA Buyers: What Happens After the Home Inspection? (2025 Guide)
 

A competitive market doesn’t mean you should skip critical inspections.

Final Thoughts

In Washington, a sewer scope is one of the highest-value inspections a buyer can do. It’s quick, affordable, and can save you from major repair costs down the road. Whether you're buying a home built in 1920 or 2020, protecting yourself with a sewer scope is one of the smartest decisions you can make.

If you're planning a move in Washington, I’d love to help you create a plan that actually makes sense for your timeline and budget.

 Written by: Lani Fisher — Washington Realtor Helping Everyday Buyers & Sellers With Confidence