Finding bathroom vent terminations (under the insulation)

[Kenton H. Shepard, CMI]

This bathroom exhaust vent was completely buried in insulation and totally invisible.
The buyer worked with me. I had him turn them on and off one by one so it was easy to find by sound. With both bathroom fans on this floor running it was impossible to differentiate one from another. Working alone it would have been difficult to find. The only way would be to memorize the number of bathrooms and the likely locations for their terminations and then to guess at their numbers and locations.

Given the similarities in how vent terminations of various types of exhaust fans look, especially at roofs and exterior walls, does anyone have a good method for confirming exterior termination of all the vents?

[Dominic J. Maricic]

You might want to enlarge that image, it's pretty small and hard to make out.

[David P. Valley]

My report contains all vent termination points from the kitchen, bathroom, dryer and all mechanicals. I must enter the termination point into specific sections of my report.

This helps me determine where every ventable component terminates because they are included in my reports. I actually look for all vent terminations while inspecting (it's become a habit for me).

If I'm unable to locate a specific vent, I write it up as "Not Inspected" due to.....(Reason why I can't locate vent).

[Brian A. MacNeish]

When doing the exterior first, some vents and their use are easily discernible. After I complete the interior inspection, I walk around the outside once more looking for exterior vent terminations for each fan or appliance not accounted for in the exterior inspection. At the end you will know how many vents there should be and may know which direction the floor joists run and where you may expect a vent hood from the main floor washroom of a 2 story dwelling. No simple way of doing this.

[lfoster]

And then there was an older home we inspected. The dryer duct venting had been stuffed into the soffit area at the front porch, and there was lint hanging out of the soffit vent holes.

Most of the time though, they are hard to find. So many of the builders in our area do not vent the exhaust fans through the roof. Was not specified until the 2006 IRC.

Looked at a new home the other day and the exhaust vents were laying around in the attic space. These people had also joined the TPR drain lines for two water heaters at a 't' and then ran to outside. The builder wasn't happy with us.

[Peter C. Russell]

Thermal Imaging works good.

[Frank M. Carrio, CMI]

Originally Posted by lfoster

And then there was an older home we inspected. The dryer duct venting had been stuffed into the soffit area at the front porch, and there was lint hanging out of the soffit vent holes.

Most of the time though, they are hard to find. So many of the builders in our area do not vent the exhaust fans through the roof. Was not specified until the 2006 IRC.

Looked at a new home the other day and the exhaust vents were laying around in the attic space. These people had also joined the TPR drain lines for two water heaters at a 't' and then ran to outside. The builder wasn't happy with us.

Here is some information from 2003
2003 International Residential Code for One and Two Family Dwellings
Chapter 3, Building Planning
R-303 Light, Ventilation and Heating
303.3 Bathrooms.
Bathrooms, water closet compartments and other similar rooms shall be provided with aggregate glazing area in windows of not less than 3 square feet (0.279 m2), one-half of which must be openable.
Exception: The glazed areas shall not be required where artificial light and a mechanical ventilation system are provided. The minimum ventilation rates shall be 50 cfm (23.6 L/s) for intermittent ventilation or 20 cfm (9.4 L/s) for continuous ventilation. Ventilation air from the space shall be exhausted directly to the outside.

Chapter 15 Exhaust Systems.
M1506
MECHANICAL VENTILATION
M1506.1 General.
Where toilet rooms and bathrooms are mechanically ventilated, the ventilation equipment shall be installed in accordance with this section.

M1506.2 Recirculation of air.
Exhaust air from bathrooms and toilet rooms shall not be recirculated within a residence or to another dwelling unit.
.
M1506.3 Ventilation rate.
Ventilation systems shall be designed to have the capacity to exhaust the minimum air flow rate determined in accordance with TableM1506.3.

2003 ICC Performance Code for Buildings and Facilities
Part II. – Building
Chapter 9, Moisture
Section 903 Internal Moisture
The use of ventilation is another way to combat internal moisture. Chapter 12 of the IBC requires ventilation in accordance with the IMC. Chapter 4 of the IMC sets specific exhaust rates for particular use groups and areas within those use groups. For example, for toilet rooms and bathrooms within one- and two-family dwellings, 50 cfm (923.L/s) intermittent or 20 cfm (9.4 L/s) continuous airflow is required.
This serves to remove odors and moisture from the enclosure

[Frank M. Carrio, CMI]

Here is some information from 1997;

1997 UBC 1202.2.1 Ventilation

"Toilet rooms shall be provided with a fully openable exterior window with an area not less than 3 square feet, or a vertical duct not less than 100 square inches in area for the first water closet plus 50 square inches additional of area for each additional water closet, or a mechanically operated exhaust vent system capable of providing a complete change of air every 15 minutes.
Such mechanically operated exhaust system shall be connected directly to the outside, and the point of discharge shall be at least 3 feet from any opening that allows air entry into occupied portions of the building."

[Frank M. Carrio, CMI]

Looking for the most current information?

HERE YA GO!

The 2006 International Residential Code for One and Two Family Dwellings

Definition:
ENVIRONMENTAL AIR.
Air that is conveyed to or from occupied areas through ducts which are not part of the heating or air-conditioning system, such as ventilation for human usage, domestic kitchen range exhaust, bathroom exhaust and domestic clothes dryer exhaust.

IRC, Section Are 303, Light, Ventilation, and Heating.
R303.3 Bathrooms.
Bathrooms, water closet compartments and other similar rooms shall be provided with aggregate glazing area in windows of not less than 3 square feet (0.3 m2), one-half of which must be openable.
Exception: The glazed areas shall not be required where artificial light and a mechanical ventilation system are provided. The minimum ventilation rates shall be 50 cubic feet per minute (24 L/s) for intermittent ventilation or 20 cubic feet per minute (10 L/s) for continuous ventilation. Ventilation air from the space shall be exhausted directly to the outside.

IRC, Chapter 15, SECTION M1507, MECHANICAL VENTILATION
M1507.1 General.
Where toilet rooms and bathrooms are mechanically ventilated, the ventilation equipment shall be installed in accordance with this section.

M1506.2 Recirculation of air.
Exhaust air from bathrooms and toilet rooms shall not be recirculated within a residence or to another dwelling unit and shall be exhausted directly to the outdoors. Exhaust air from bathrooms and toilet rooms shall not discharge into an attic, crawl space or other areas inside the building.

M1507.3 Ventilation rate.
Ventilation systems shall be designed to have the capacity to exhaust the minimum air flow rate determined in accordance with Table M1507.3. Mechanical exhaust capacity of 50 CFM intermittent or 20 CFM continuous

2006, International Mechanical Code
502.18 Specific rooms.
Specific rooms, including bathrooms, locker rooms, smoking lounges and toilet rooms, shall be exhausted in accordance with the ventilation requirements of Chapter 4.

2006, International Property Maintenance Code
Definition:
BATHROOM. A room containing plumbing fixtures including a bathtub or shower.

Chapter 4, Light, Ventilation, and Occupancy Limitations

SECTION 403, VENTILATION
403.2 Bathrooms and toilet rooms.
Every bathroom and toilet room shall comply with the ventilation requirements for habitable spaces as required by Section 403.1, except that a window shall not be required in such spaces equipped with a mechanical ventilation system. Air exhausted by a mechanical ventilation system from a bathroom or toilet room shall discharge to the outdoors and shall not be recirculated.

403.4 Process ventilation.
Where injurious, toxic, irritating or noxious fumes, gases, dusts or mists are generated, a local exhaust ventilation system shall be provided to remove the contaminating agent at the source. Air shall be exhausted to the exterior and not be recirculated to any space.

2006 International Plumbing Code
Definition:
BATHROOM GROUP. A group of fixtures consisting of a water closet, lavatory, bathtub or shower, including or excluding a bidet, an emergency floor drain or both. Such fixtures are located together on the same floor level.

2006 International Building Code
IBC, 1203.4.2.1 Bathrooms.
Rooms containing bathtubs, showers, spas and similar bathing fixtures shall be mechanically ventilated in accordance with the International Mechanical Code.
{See Chapter 15, SECTION M1507 MECHANICAL VENTILATION, M1507.1 General. located above}

2006, ICC Performance Code for Buildings and Facilities
Chapter 9 Moisture, Section 903 Internal Moisture
903.3 Performance requirements.
903.3.1 Excess moisture removal and protection.
An adequate means shall be provided to remove excess moisture or protect the structure from the effects of excess moisture and condensation to all habitable spaces, bathrooms, laundries and other locations where moisture may be generated.

I hope that this information can be of some help.

[Brian A. MacNeish]

Here's the kicker on the 50 cfm intermittent for the bath/washrooms:
Is this 50 cfm operational or a 50 cfm fan ?

A large national company makes a 50 cfm piece of crap ($15-$20) that operates way below 50 cfm when ducting and an exterior hood with damper are installed. This unit will move 50 cfm when sitting on the table with no ducting connecting to it but it is a paddle wheel impeller that has no real power to drive air through a poor duct system. To ensure 50 cfm operational would require a 70-90 cfm fan depending on the resistances of the ducts, dampers, etc.

[Frank M. Carrio, CMI]

Originally Posted by Brian A. MacNeish

Here's the kicker on the 50 cfm intermittent for the bath/washrooms:
Is this 50 cfm operational or a 50 cfm fan ?

A large national company makes a 50 cfm piece of crap ($15-$20) that operates way below 50 cfm when ducting and an exterior hood with damper are installed. This unit will move 50 cfm when sitting on the table with no ducting connecting to it but it is a paddle wheel impeller that has no real power to drive air through a poor duct system. To ensure 50 cfm operational would require a 70-90 cfm fan depending on the resistances of the ducts, dampers, etc.

IRC, Chapter 15, SECTION M1507, MECHANICAL VENTILATION
M1507.1 General.
Where toilet rooms and bathrooms are mechanically ventilated, the ventilation equipment shall be installed in accordance with this section.

M1506.2 Recirculation of air.
Exhaust air from bathrooms and toilet rooms shall not be recirculated within a residence or to another dwelling unit and shall be exhausted directly to the outdoors. Exhaust air from bathrooms and toilet rooms shall not discharge into an attic, crawl space or other areas inside the building.

M1507.3 Ventilation rate.
Ventilation systems shall be designed to have the capacity to exhaust the minimum air flow rate determined in accordance with Table M1507.3. Mechanical exhaust capacity of 50 CFM intermittent or 20 CFM continuous

So long as it meets this standard it is "good to go".

[Mario A. Kyriacou, CHI]

Originally Posted by Brian A. MacNeish

Here's the kicker on the 50 cfm intermittent for the bath/washrooms:
Is this 50 cfm operational or a 50 cfm fan ?

A large national company makes a 50 cfm piece of crap ($15-$20) that operates way below 50 cfm when ducting and an exterior hood with damper are installed. This unit will move 50 cfm when sitting on the table with no ducting connecting to it but it is a paddle wheel impeller that has no real power to drive air through a poor duct system. To ensure 50 cfm operational would require a 70-90 cfm fan depending on the resistances of the ducts, dampers, etc.

I our Ontario Building Code "Sones" are also a requirement this with CFM requirements puts the exhaust fan in the $100+ bracket. It is also very effective. I have to run I have an Inspection to do but will put out more info later if wanted.

[Brian A. MacNeish]

Originally Posted by mkyriacou

I our Ontario Building Code "Sones" are also a requirement this with CFM requirements puts the exhaust fan in the $100+ bracket. It is also very effective. I have to run I have an Inspection to do but will put out more info later if wanted.

The model national building code has had the 2 sones or less for bathroom fans and 3.5 sones or less for range hoods since 1995.......but try to find an inspector enforcing this!!! Another reg in place since 1995 is: fan cannot not be tied in with a light switch, must have its own switch.

Last year I did a 1 year warranty (and it was also litigation inspection) on a $1.5 million house- the HVAC was $75,000 and none installed /set up correctly. None of the 5 bath fans met the sone rating in the code and one fan was dead at 11 months.

Today I started a 1 year warranty (and it was also a litigation inspection) on a $700-$800 grand house with similar problems. 3 out of 4 bath fans do not meet code; geothermal heat pump cannot heat or cool the place properly; After finding some other items, the owner (a property investor/landlord with multiple apartment buildings) asked me to find more items (the house at the deck ledgers had severe rot and water entry.....in less than a year!!) so I'll be back there tomorrow AM. He really wants to stick it to the contractor/developer!!

When you go into the big box stores and visit their "Wall of Fans and Shame", you will see that probably only 10-15% (or even less) of fans on the wall actually meet code for sound levels!!! So who's buying all these non-code compliant fans???

Three weeks ago, was working on an old work aquaintance's house and asked who put the bath fan in? It did not meet the code in 3 items1) sound level, (2) was not on a switched circuit separate from all bathroom lights and (3) it was not vented to the exterior but to the attic. Only put in 6 -7 months ago. Who put it in? A licensed electrician!!!! Not some old dog who cannot be retrained but a young pup who's had his business for 4-5 years now. How does he stay in business? How can we pull licenses??

Paul A. Come up here and starighten out our sparkies. I'm running up against them fairly regularly now.....and have not lost a battle for years. In early summer, did pre-buy inspections on 2 electrician's homes (one for friends who moved to the area "from away" [a Maritime phrase]); both homes were rejected due to "electrical". One guy worked for a large national transportation interest and I may not travel on their equipment again!!

[Keith R. Braun]

Kenton,
Generally I begin on exterior from top to bottom, making mental notes as to vent terminations, if any, looking for clues on the roof, soffits, sidewalls, basement windows, etc. These items may be power roof ventilators, bathroom exhausts, range hood exhausts, downflow Jenn Air exhausts, clothes dryer exhausts.
Next, when checking bathrooms, if there is a ceiling mounted fan I recall my notes and the approximate location of where the termination might be for that particular vent.
Finally, before checking the attic or crawl space, remember to leave all bathroom exhausts in the 'on' position to help determine their locations. Look for visible ducts venting to the exterior and determine if that number equals the number of fans.
Approximately 90% of the residential properties I look at have deficiencies in the category of proper venting. I write them as improperly vented fans, state the possible implications(mold, condensation, insects, etc.), and recommend a qualified contractor evaluate and repair.
By the way, I enjoyed your NACHI TV Episode. I feel you're much too knowlegable for me to be giving you any advice, but this is the method that works for me.

[Kenton H. Shepard, CMI]

Always something new to learn in this business Keith, I enjoy hearing from other inspectors how they operate. A lot of experience rolls accross these boards.