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Bathroom and sanitary

Is it okay to vent my bathroom fan into the attic space?

Anonymous user 27/02/2026 - 4:35 PM

Hi there, we had our bathroom done 7 years ago and part of the design included installing an exhaust fan in the ceiling right above the shower. Now that we're getting ready to sell our house, we've found that the exhaust fan is venting straight into the attic. After doing a bit of research, we've realized this might be an issue. We contacted the contractor who did the bathroom and he insists it's fine for the fan to vent into the attic but we're not convinced. We're worried this could come up on a home inspection report and we might have to fix it or knock some money off our selling price... plus there's the matter of any damage in the attic from moisture. We've given him numerous chances to sort this out but it seems like he's avoiding it. Is it actually against the code to have a fan vent into the attic? Will this come up on an inspection report? If that's the case who can we reach out to for help in getting this sorted out? Any help or advice would be really appreciated!

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6 Answers

JG Contracting

Rating: 5 out of 5

North York

Venting a bathroom fan directly into the attic is not okay. Building codes require bathroom fans to exhaust to the outside so moisture doesn’t get trapped in the attic, which can lead to mould, wood rot, and insulation damage. This will almost certainly come up on a home inspection, and it can affect your sale if not fixed. The proper solution is to extend the duct from the fan to the exterior, usually through a roof or soffit vent. A licensed electrician or a contractor who handles bathroom renovations can assess your setup and install the vent correctly. Fixing it now will prevent moisture issues and make the house easier to sell.

Answered6 January 2026

SureFix General Contracting

Rating: 5 out of 5

Fordwich

It is definitely not okay to vent any ventilation fan into an attic space. Direct ventilation to the exterior of the home is required to remove all moisture outside. Leaving it this way in the long term will cause mold, wood rot and insulation damage. It will need to be vented out of the roof directly or through a soffit. An inspector will flag this during an inspection and it will definitely decrease your ability to sell the home without other questions like air quality and structural damage. If you choose to do the vent through the roof, it is recommended to call a roofing professional to properly place the exterior vent to prevent future leaks. Connecting the vent pipe can be done by a handyman or an HVAC pro. If you go the route of the soffit, you can get a handyman or HVAC pro to do the pipe and exterior vent in the soffit.

Answered7 January 2026

Porch Light Reno Inc

Rating: 5 out of 5

Unionville

Absolutely not ok. Mold will form and lead to more problems. Have a roofer come in to install a bathroom vent out for the exhaust

Answered9 January 2026

New Design Renovations

Rating: 5 out of 5

Toronto

Its not a good ideal too vent the bathroom exhaust fan up into the attic because it could cause a lot of problem like mold if they have a good inspector it will come up on the report. best to get this resolve as soon as posable.

Answered12 January 2026

Electrician

Rating: 5 out of 5

Calgary, Alberta

Unfortunately you cannot do it. Moisture will build app and can be very unsafe with time. Contact a professional to do the right job

Answered12 January 2026

Jas Renovations

No reviews yet

Mississauga

Ontario building code (Part 9, Ventilation) states: "Exhaust ducts shall not discharge into heated or unheated enclosed spaces." The attic is an enclosed space.Dumping moisture rich air, warm air into the attic will create condensation, resulting in mold and mildew, damaged insulation and likely result in wood rot overtime. Furthermore it would likely come up in any future home inspections as an issue if you want to sell the property, etc.

Answered27 February 2026