Sending this question in to my favorite community. Hoping to get some good insights.
We have a rental in San Jose area. The house is quite old and has a sunroom at the back which is built with metal paneling. Looks like there was a waterproof coating on the roof that has worn out and may be water is leaking slowly. That has caused some mold inside the ceiling. The mold screening company recommended some vendors. The vendors are recommending typical approaches such as cleaning mold from inside, drying out the moisture but also removing the paneling from walls and ceiling to completely get rid of the source. If they remove any paneling, we will have to completely rebuild the sunroom as those parts aren't available anymore.
We plan to remove the mold as much as possible by the non-invasive way but that doesn't gurantee complete removal of the mold. We wil also apply the waterproof coating on the roof.
We have already offered our tenants to leave without any lease breaking fees if they feel uncomfortable. They have opted to stay.
Question is - What is the right apporach here for the mold, as well as landlord duties and also, for future renting if this tenant leaves?
thank you so much in advance. always appreacite the help.
This is a tough situation but you're already doing a lot of things right. A few things worth knowing:
On the remediation approach: The non-invasive cleaning plan is unfortunately not going to be sufficient if the mold is in drywall or ceiling material. The industry standard (IICRC S520) is clear on this: for porous materials like drywall and ceiling tiles, mold roots embed deep into the material and can't be cleaned out. The correct approach is to cut out and physically remove the affected sections, fix the moisture source, then rebuild. Cleaning and recoating over moldy drywall leaves you exposed legally and the problem will come back.
Fixing the waterproofing on the roof is absolutely the right call and needs to happen regardless. That's the source and nothing else matters until that's resolved.
Regarding California law, I live in Florida so I did some quick research on this since the laws are a bit different. Under Civil Code 1941.1, you're required to maintain a habitable unit, which explicitly includes keeping it free from substantial mold caused by water intrusion. Health and Safety Code 26147 also requires written disclosure if you know mold exists at levels that pose a health risk. Given you already know about it, you're on the clock. California gives landlords "reasonable time" to remediate but mold compresses that window significantly, especially if a tenant ever gets a doctor's note involved.
Offering to let your tenant leave without penalty was the right move and shows good faith. Just know it doesn't retroactively eliminate liability if they were already exposed and later develop health issues.
Regarding future tenants, if the mold is professionally and completely remediated before a new tenant moves in, California generally does not require you to disclose the past mold issue to future tenants. But the key word is professionally. You want an IICRC-certified remediator doing the work, not just a general contractor with bleach. Get a post-remediation air clearance test done independently after the work is complete. That test result is your legal shield if anyone ever challenges you later.
What to document right now:
Everything in writing. Every conversation with your tenant about this should be confirmed via email or text.
Photos of the leak source, the affected area, and every stage of the repair.
The professional remediation invoice.
The post-remediation clearance test.
The CDPH mold informational booklet. As of 2022 California requires landlords to provide this to all new tenants at lease signing. Add it to your standard lease packet going forward.
Not a lawyer and this isn't legal advice, but the path forward is pretty clear: get a certified remediator in to do a proper source removal, not just a surface clean, get the roof waterproofed, document everything, and get that clearance test. That protects you now and for future tenants.
This is a tough situation but you're already doing a lot of things right. A few things worth knowing:
On the remediation approach: The non-invasive cleaning plan is unfortunately not going to be sufficient if the mold is in drywall or ceiling material. The industry standard (IICRC S520) is clear on this: for porous materials like drywall and ceiling tiles, mold roots embed deep into the material and can't be cleaned out. The correct approach is to cut out and physically remove the affected sections, fix the moisture source, then rebuild. Cleaning and recoating over moldy drywall leaves you exposed legally and the problem will come back.
Fixing the waterproofing on the roof is absolutely the right call and needs to happen regardless. That's the source and nothing else matters until that's resolved.
Regarding California law, I live in Florida so I did some quick research on this since the laws are a bit different. Under Civil Code 1941.1, you're required to maintain a habitable unit, which explicitly includes keeping it free from substantial mold caused by water intrusion. Health and Safety Code 26147 also requires written disclosure if you know mold exists at levels that pose a health risk. Given you already know about it, you're on the clock. California gives landlords "reasonable time" to remediate but mold compresses that window significantly, especially if a tenant ever gets a doctor's note involved.
Offering to let your tenant leave without penalty was the right move and shows good faith. Just know it doesn't retroactively eliminate liability if they were already exposed and later develop health issues.
Regarding future tenants, if the mold is professionally and completely remediated before a new tenant moves in, California generally does not require you to disclose the past mold issue to future tenants. But the key word is professionally. You want an IICRC-certified remediator doing the work, not just a general contractor with bleach. Get a post-remediation air clearance test done independently after the work is complete. That test result is your legal shield if anyone ever challenges you later.
What to document right now:
Everything in writing. Every conversation with your tenant about this should be confirmed via email or text.
Photos of the leak source, the affected area, and every stage of the repair.
The professional remediation invoice.
The post-remediation clearance test.
The CDPH mold informational booklet. As of 2022 California requires landlords to provide this to all new tenants at lease signing. Add it to your standard lease packet going forward.
Not a lawyer and this isn't legal advice, but the path forward is pretty clear: get a certified remediator in to do a proper source removal, not just a surface clean, get the roof waterproofed, document everything, and get that clearance test. That protects you now and for future tenants.
I am not familiar with your local Cali laws, but I'll back up what @Ricardo Gonzalez stated. You must remove the paneling/ceiling, or you will have mold growing in the walls, and, for anyone sensitive to it, the odor will be unmistakable. Additionally, if as you say this was a slow, long term seepage, there is likely additional damage to the structural elements that you cannot see until those finishes are removed. You always need to follow the signs of water intrusion back to the actual source. It may well be just the coating, or it may be bad flashing, or gaps around protrusions. It also may be getting under the existing roof on the far side of the room, causing water damage to the roof deck across the entire space that you cannot see. Fix it right, fix it once.
I'd be cautious about relying on a partial fix if the source of the moisture isn't fully addressed. In my experience, mold is usually a symptom of an underlying water issue, and if that issue remains, there's a good chance the problem will return.
Since you're in California, I'd also recommend working closely with qualified remediation professionals and making sure you understand your state and local habitability and disclosure requirements. Those can be just as important as the repair itself.
From an operational standpoint, I'd focus on documenting everything—the inspections, contractor recommendations, remediation work, and communication with the residents. Good documentation and resolving the moisture source are usually the best ways to protect both the property and everyone involved.
Sending this question in to my favorite community. Hoping to get some good insights.
We have a rental in San Jose area. The house is quite old and has a sunroom at the back which is built with metal paneling. Looks like there was a waterproof coating on the roof that has worn out and may be water is leaking slowly. That has caused some mold inside the ceiling. The mold screening company recommended some vendors. The vendors are recommending typical approaches such as cleaning mold from inside, drying out the moisture but also removing the paneling from walls and ceiling to completely get rid of the source. If they remove any paneling, we will have to completely rebuild the sunroom as those parts aren't available anymore.
We plan to remove the mold as much as possible by the non-invasive way but that doesn't gurantee complete removal of the mold. We wil also apply the waterproof coating on the roof.
We have already offered our tenants to leave without any lease breaking fees if they feel uncomfortable. They have opted to stay.
Question is - What is the right apporach here for the mold, as well as landlord duties and also, for future renting if this tenant leaves?
thank you so much in advance. always appreacite the help.
Mold is a VERY misunderstood issue that everyone seems to panic about.
FIRST - there is mold in EVERY property. It's just a matter of how much and what kind.
SECOND - per our three real estate attorneys, a landlord should do everything they can to NEVER get a mold test. You can't stop a tenant from getting one, but you want to try to address any mold concerns without tests or anything else that increases your potential liability.
Regarding the existing tenants, get with an attorney ASAP to see if they can create a Hold Harmless Agreement for the tenants to sign that reduces your potential liability exposure if they choose to stay.
Another mold-remediation option that we've used, and documented it works with before & after mold tests, is an ozone machine. Ozone will kill mold spores, but requires near-lethal amounts. So, tenants will have to leave property for a day or two. You can also pump the ozone into wall or ceiling spaces. You can rent one at Home Depot.
TRUE STORY: best mold expert we've ever known, told a story about tenants freaking about about mold in their rental and had tests to support. Problem was the tenants didn't take any control samples of the outside mold levels. He was hired by the insurance company involved and so he followed proper protocols and took indoor & outdoor samples. Home was near a swamp and his tests and the subsequent tests of the plaintiffs/tenants showed the levels of mold were HIGHER outside than inside! Case was quickly settled.
I completely relate to this, especially operating in San Francisco. Moisture buildup was a constant struggle for me until I installed a dehumidifier—I haven't seen a spot of mold since.
Mold tends to thrive in areas with poor airflow, so if you have tenants with high-density storage or hoarding tendencies, you can bet it's brewing in those tight corners. As landlords, even when we know the tenant's lifestyle is driving the issue, we still have to inspect and remediate promptly. Documenting your response and taking action is critical so there's no claim that you neglected habitability standard.
I know exactly where you are coming from especially in the Bay Area, I am located in San Francisco and I use to have this issue until i installed a Dehumidifier. Have not seen mold ever since. Mold typically are found in congested spots, so if your tenants are hoarders, i am 100 percent sure in some corners you will find mold spots. As a landlord, you have to address the issue even though you know it will be repetitive. You don't want to show that you do not care and address issue because tenants will use it against you.
How will the new tenant know if the previous tenant complained of mold and it was cleaned up by a regular contractor. There might still be some mold but if it doesn't smell and you can't see it and there are no leaks then what is the BFD?
Honestly, the city probably has no idea unless a neighbor reported it. If there’s a record, it’ll show up—but that’s a whole separate mess. Either way, if you end up hiring a contractor to fix it, hang onto your receipts. You’ll want proof in case the city comes asking for reference later.
