Mould After a Leak: What to Do (and When to Call a Pro)

Home › Guides › Mould After a Leak: What to Do (and When to Call a Pro)

Where there's been water, mould often follows — the EPA notes it can start within 24–48 hours. Here's how to handle it.

Small areas you can often clean yourself

Under about 10 square feet on a hard surface, you can usually clean it — wear a mask and gloves, scrub with detergent and water, and dry completely. Always fix the moisture source first, or it comes straight back.

Call a professional when…

• The area is larger than ~10 sq ft.
• Mould is in the HVAC system (it can spread through the whole house).
• It followed sewage or serious flooding.
• Anyone in the home has asthma, allergies, or a weakened immune system.

A mould remediation pro contains the area, removes it safely, and treats what's left. Expect $500–$6,000 depending on size and location.

Stopping it coming back

Remediation without fixing the cause is temporary. Deal with the leak, improve drainage or ventilation, and waterproof if water keeps getting in.

Source: U.S. EPA mould & moisture guidance. General information only.

Get free local quotes →