Oregon is one of the wettest states in the country. All that rain makes mold a real problem for renters and homeowners alike. If you’ve found mold in your rental, you’re not alone. Millions of Oregonians deal with this every year.
This guide breaks down exactly what Oregon law says about mold. You’ll learn what landlords must do, what you can do if they don’t, and how the rules changed in 2026.
What Is Mold and Why Does Oregon Law Care?
Mold is a type of fungus. It grows wherever there is moisture and poor airflow. Bathrooms, basements, and walls near leaky pipes are common spots.
Some molds are harmless. Others can cause serious health problems. That’s why Oregon law treats mold as a housing safety issue. Right?
Oregon doesn’t have one single “mold law.” Instead, mold is handled through the state’s housing and tenant laws. The main law is called ORS 90.320. It’s part of the Oregon Residential Landlord and Tenant Act.
Oregon’s Basic Mold Laws
The Habitability Standard
Oregon requires every rental home to be livable. That’s called the “habitability standard.” Under ORS 90.320, landlords must keep your home safe, clean, and weatherproof.
The law doesn’t say the word “mold” specifically. But courts have interpreted it clearly. If a landlord ignores moisture problems that cause mold, they are breaking the habitability law.
Wondering if mold counts as a habitability issue? It almost always does. Especially if it comes from a leaky roof, broken pipe, or bad ventilation.
Who Is Responsible?
Here’s where it gets interesting. Responsibility for mold depends on the cause.
If mold grows because of a structural problem, the landlord is responsible. A leaky roof is one example. Broken plumbing is another. Poor ventilation that came with the unit is a third.
But tenants have responsibilities too. You are expected to ventilate your home properly. That means running bathroom fans during showers. It means reporting leaks quickly. If you ignore a small leak for months and mold spreads, you could be held responsible for the damage.
Think of it like a traffic ticket, but shared between two drivers. Both parties have a role.
Landlord Duties Under Oregon Law
What Landlords Must Do
Landlords must keep your home dry and structurally sound. That includes fixing roof leaks. It includes repairing broken plumbing. It includes making sure exhaust fans work properly.
Honestly, this is the part most people miss. Many renters don’t realize that a landlord who ignores a dripping pipe is already breaking the law, even before mold appears.
Under ORS 90.365, if you give your landlord written notice about a mold problem, they have to act fast. For urgent health and safety issues like mold from a water leak, Oregon law generally requires action within 7 days. Less serious repairs must be done within 30 days.
The 2026 Update: HB 3521
Okay, pause. Read this carefully.
A new law took effect on January 1, 2026. It’s called House Bill 3521. It protects renters who haven’t signed a lease yet.
Here’s how it works. Say you pay a hold deposit to secure an apartment. Then you walk through the unit and discover mold. Under the old rules, you could lose that deposit if you backed out. Under HB 3521, if the mold makes the unit uninhabitable, you get your full deposit back. The landlord has five days to return it. If they don’t, they could owe you a penalty equal to the amount of the deposit.
Pretty significant protection for new renters.
Tenant Rights When Mold Is Found
Your Legal Options
So what happens if you break this news to your landlord and they ignore you?
Oregon law gives you several options. You can withhold rent, but only after following very specific steps. You can repair the problem yourself and deduct the cost from rent. For minor repairs, the repair-and-deduct limit is $300. You can also end your lease early if the unit is truly unlivable.
For severe situations, like mold that poses an immediate threat to your health, you can give 48 hours written notice and walk away from your lease.
Wait, it gets better. If your landlord tries to evict you for complaining about mold, that is called retaliation. Oregon law prohibits it under ORS 90.385. You have legal protection simply for reporting the problem.
The Importance of Written Notice
Most people don’t realize how strict these rules are. Verbal complaints are not enough in Oregon. You need written notice. Every time.
Your written notice should include the date you first noticed the mold. Describe where it is and how much there is. Mention any possible causes, like a nearby leak. Request a specific timeline for repairs. Keep a copy of everything you send.
This documentation is your legal protection. Without it, your options shrink fast.
Portland’s Stricter Mold Rules
Don’t worry, we’ll break it down step by step. But if you rent in Portland, you need to know about local rules.
Portland has its own mold regulations under Title 29 of the City Code. Section 29.30.120 specifically covers interior dampness. Under Portland rules, all rental properties must be kept free from visible mold or mildew, full stop.
Here’s where Portland goes further than state law. When visible mold covers more than one square foot, landlords must install or upgrade bathroom ventilation systems. If mold is “major,” meaning more than 10 square feet, the landlord must hire a Certified Mold Remediation Contractor.
Portland also offers financial assistance to low-income tenants who are dealing with health issues related to mold. That’s something the state doesn’t provide on its own.
To report a mold violation in Portland, you can call Neighborhood Inspections at 503-823-7306.
Penalties and Consequences
For Landlords
Landlords who ignore mold problems face real consequences. They can be forced to make repairs at their own expense. They can owe you money for reduced rent value during the time the mold was present.
If the unit becomes truly uninhabitable, landlords may have to pay for your temporary housing. In Portland, relocation assistance may kick in when a tenant is forced to leave because of conditions the landlord caused.
Landlords who retaliate against tenants for reporting mold can also face extra penalties under Oregon law.
For Tenants Who Misuse the Rules
Here’s the flip side. If you try to withhold rent or end your lease without following Oregon’s specific steps, you could face eviction. Rent withholding is risky and should be done with legal guidance.
Less severe than going to court, but still no joke. Always follow the legal steps.
Special Circumstances
What About Disclosure?
A friend asked me about this last week. Do Oregon landlords have to tell you about mold before you move in? Turns out, most people get this wrong.
Oregon does not currently require landlords to disclose past or present mold before renting a property. That might surprise you. However, Oregon’s Unlawful Trade Practices Act does offer some protection. Landlords cannot actively misrepresent the condition of a rental. If you suffer health or financial harm from mold they knew about but hid, you may have legal grounds to act.
Under HB 3521, which took effect in 2026, prospective tenants now have stronger protection during the pre-lease period. If undisclosed defects including mold are discovered, you can walk away and get your deposit back.
What If You Caused the Mold?
Stay with me here. Tenants are not always off the hook.
If mold grew because you never ran the bathroom exhaust fan, the landlord may not be responsible. The same applies if you dried clothes indoors without ventilation, or kept an unusual number of indoor plants that raised humidity levels. If you saw a small leak but waited months to report it, you could share liability for the resulting damage.
The key question is always: what caused the mold? Responsibility follows the cause.
How to Handle a Mold Problem
Here is what you should actually do if you find mold in your Oregon rental.
First, document everything immediately. Take photos and videos. Note the date and location.
Second, notify your landlord in writing. Email works. Certified mail works even better. Include the date you found it, where it is, and what you think caused it.
Third, keep copies of everything. Every email, every text, every letter.
Fourth, give your landlord the time the law requires. In urgent cases, that’s 7 days. For less severe issues, it’s up to 30 days.
Fifth, if they don’t respond, contact your local code enforcement office. Portland renters can call 503-823-7306. Tenants elsewhere can contact their city or county housing office.
Sixth, if health is being affected or the situation doesn’t resolve, contact a tenant rights organization or a lawyer. Oregon has free legal aid resources for qualifying renters.
You’re gonna love this last tip. Oregon’s Department of Justice has a free consumer protection hotline. If you believe a landlord misrepresented a property’s condition, you can file a complaint with them.
Frequently Asked Questions
Does Oregon require landlords to test for mold?
No. Oregon does not require routine mold testing. Landlords are required to address visible mold and the moisture conditions that cause it, but there is no state mandate for professional testing.
Can I break my lease because of mold?
Yes, under certain conditions. Under ORS 90.360, if your landlord fails to fix a serious habitability problem after proper written notice, you can give 30 days written notice and terminate your lease. For immediate health threats, you can give 48 hours notice.
Can my landlord deduct mold damage from my security deposit?
Yes, if you caused the mold. Landlords can deduct for actual damage beyond normal wear and tear. If the mold resulted from your failure to ventilate or your failure to report a leak, a deduction may be valid.
What counts as “major” mold in Portland?
Portland’s rules define major mold as any visible growth exceeding 10 square feet in total. That level of mold requires a Certified Mold Remediation Contractor and triggers stricter remediation requirements.
Who do I call if my Oregon landlord ignores a mold complaint?
Outside Portland, contact your local code enforcement office or the Oregon Bureau of Labor and Industries. Portland tenants can call Neighborhood Inspections at 503-823-7306. You can also contact Oregon Legal Aid Services for free legal guidance.
Final Thoughts
Mold is a health issue. It is also a legal issue. Oregon law is clear that landlords must keep your home dry, safe, and livable.
Document everything in writing. Report problems as soon as you find them. Know your rights under ORS 90.320 and the 2026 updates under HB 3521. And if you live in Portland, remember that your local rules go even further than state law.
Now you know the basics. Stay informed, stay safe, and when in doubt, call Oregon Legal Aid or consult a local tenant rights organization.
