Mechanical Rough-In Inspection Checklist

Use the Mechanical Rough-In Inspection Checklist to check all elements for compliance with the 2018 International Residential Code (IRC).​

Mechanical Rough-In Inspection Checklist



Permits And Plans

1. Is the job address posted in a visible location?


Photo Comment

2. Are the permit and approved plans available on the site ?


Photo Comment

3. Is the permit information correct, including the address, permit number, description of work, etc.?


Photo Comment

4. Is the duct rough-in test affidavit on-site and available to the inspector? Is a maximum of 4 cubic feet per minute (CFM) per 100 square feet (SF) with an air handler installed or 3 CFM per 100 SF without an air handler installed?


Photo Comment
Forced-Air Furnace

1. Are fuel-burning appliances installed in compliance with location restrictions, such as not being in sleeping rooms, bathrooms, toilet rooms, storage closets, or spaces that open into such areas, unless they are direct vents or listed for use within living space ?


Photo Comment

2. Are heat-producing equipment installations maintained with clearances to combustibles as required by the appliance listing and the manufacturer's installation instructions ?


Photo Comment

3. Is the furnace room passageway a minimum of 24 inches wide ?


Photo Comment

4. Are specific requirements for the installation of mechanical equipment in attics and crawl spaces followed according ?


Photo Comment

5. Is the working space for mechanical equipment 30 inches deep to the height of the unit or a minimum of 30 inches (M1305.1)? Is a clearance of 3 inches provided along the sides, back, and top with a total width of the space being at least 12 inches wider than the furnace? Do furnaces having a firebox open to the atmosphere have at least a 6-inch working space along the front combustion chamber side?


Photo Comment

6. Is an electrical receptacle provided at or near the appliance, within 25 feet per NEC ?


Photo Comment

7. Are means of disconnect provided within sight of the appliance or is the breaker capable of being locked in the open position )?


Photo Comment

8. Are switch-controlled lighting (light protected or away from access) and a receptacle outlet provided at the required passageway for servicing equipment?


Photo Comment

9. Is the installation of wall furnaces performed in accordance with the listing and manufacturer's installation instructions?


Photo Comment
Underfloor And Antics

1. When a furnace is installed in an underfloor area, is it suspended a minimum of 6 inches above grade or installed on a slab extending above adjoining grade?


Photo Comment

2. For equipment installed on wood platforms within 18 inches of soil to the bottom of the framing, is the framing and sheathing preservative-treated ?


Photo Comment

3. Are excavations or pits for equipment installed with minimum requirements, as specified in the installation instructions ?


Photo Comment
Garage

1. Are specific requirements for equipment located in garages followed, such as elevating equipment with a flame, spark, or glowing ignition source at least 18 inches above the floor, unless it's a flammable vapor ignition-resistant appliance ?


Photo Comment

2. Do ducts penetrating a wall or ceiling separating the garage from the dwelling have 26-gauge construction and no openings to the garage ?


Photo Comment

3. Is a bollard or wheel stop required in front of or to the side of equipment if it's subject to impact by an automobile?


Photo Comment
Condensing Furnace (High Efficiency)

1. Is a condensate drain available to drain by gravity to an approved place of disposal or is a UL 508-approved condensate pump installed ?


Photo Comment

2. Is the drainpipe minimum of 3/4 inch with a ? inch per foot slope ?


Photo Comment

3. Is the drainpipe allowed to drain to an indirect receptor (lavatory tailpiece, tub overflow, etc.) ?


Photo Comment

4. Are the piping materials correctly identified, such as the manufacturer's identification on all fittings ?


Photo Comment

5. Are evaporative cooling equipment connected to potable water equipped with a backflow assembly ?


Photo Comment
General

1. Does duct-to-ground have a minimum 4-inch clearance?


Photo Comment

2. Is the duct in or under concrete encased by concrete a minimum of 2 inches thick?


Photo Comment

3. Do round ducts have crimped joints lapped a minimum of 1 inch and fastened with (3) sheet-metal screws or rivets equally spaced around the joint?


Photo Comment

4. Are joints, seams, and fittings of ducts sealed with mastic or other approved means?


Photo Comment

5. Is flexible duct supported according to the manufacturer's specifications?


Photo Comment

6. Are metal ducts supported every 10 feet minimum ?


Photo Comment

7. Is ductwork not displacing the required insulation of walls, floors, or ceilings, and are building cavities not used as ducts?


Photo Comment

8. Is the venting system not extending into or passing through any fabricated air duct or furnace plenum?


Photo Comment
Return Air

1. Is return air taken from a room or space not greater than the flow rate of supply air delivered to a room or space? (M1602.2, Item 2)?


Photo Comment

2. Is return air ensured that it is not taken from a closet, bathroom, toilet room, kitchen, garage, boiler room, furnace room, unconditioned attic, or other dwelling unit? Are dedicated systems serving only a garage have obtained return from the garage served? Does return air not discharge from one dwelling unit to another dwelling unit?


Photo Comment

3. Are return air inlets ensured they are not located within 10 feet of any fuel-burning appliance firebox or draft hood located in the same space?


Photo Comment

4. Is minimum return, air transfer openings, and duct size in accordance with appliance or equipment manufacturers’ installation instructions; Manual ”D”; or by a Registered Design Professional? (Forced air furnaces minimum outside, return air, openings 2 square inches/ kBtu/ hr. (Electric Heat pumps per UL 1995)).


Photo Comment

5. Do Ducts not displace exterior insulation of walls, floors, or ceilings and is it ensured that building cavities are not used as ducts?


Photo Comment

6. Do venting systems not extend into or pass through any fabricated air duct or furnace plenum?


Photo Comment
Insulation

1. Are ducts, boots, and connectors used for heating or cooling insulated to at least R-8 in unconditioned spaces ?


Photo Comment

2. Is it ensured that ducts do not displace exterior insulation of walls, floors, or ceilings and that building cavities are not used as ducts? Local exhaust fan ducts shall be insulated to R-4 minimum to control condensation.


Photo Comment
Combustion Air

1. Is the minimum cross-section dimension for combustion air ducting 3 inches?


Photo Comment

2. Is it ensured that ducts do not displace exterior insulation of walls, floors, or ceilings and that building cavities are not used as ducts?


Photo Comment

3. Is it ensured that venting systems do not extend into or pass through any fabricated air duct or furnace plenum?


Photo Comment

4. Is combustion air ducting screened when terminating in an attic space ?


Photo Comment

5. Is there sufficient venting when combustion air is obtained from the attic or crawl space ?


Photo Comment

6. In buildings of unusually tight construction, is combustion air obtained from outside the building ?


Photo Comment

7. Are indoor combustion air openings provided at a rate of 1 square inch per 1,000 Btu/h input of all appliances, but not less than a minimum of 100 square inches with at least one opening at the top and one at the bottom ?


Photo Comment

8. Do outdoor combustion air openings in the attic and crawl spaces communicate directly or freely with the outdoors ?


Photo Comment

9. For vertical ducts used to provide combustion air from the outdoors, is each opening sized at 1 square inch per 4,000 Btu/h of the total input rating of all appliances in the space (– Two Opening Method)?


Photo Comment

10. For horizontal ducts, are the openings sized at 1 square inch per 2,000 Btu/h of the total input rating of all appliances in the space?


Photo Comment

11. Is the one opening method used for combustion air, and are the openings sized at 1 square inch per 3,000 Btu/h of the total input rating of all appliances in the space, with placement within the top 12 inches of the space? The openings shall communicate directly or freely with the outdoors. ?


Photo Comment

12. Are outside combustion air openings screened with corrosion-resistant mesh material not smaller than 1/4 inch ?


Photo Comment

13. Is combustion air drawn from inside the building when it's of ordinary tightness, and the conditioned space is at least 50 cubic feet per 1,000 Btu/h input for all fuel-burning appliances combined ?


Photo Comment
Vents And Connectors

1. Is the venting system installed following the manufacturer’s instructions ?


Photo Comment

2. When venting two gas appliances through a common vent connector, is it ensured that the common vent connector's size is equal to the largest connector plus 50% of the smaller flue outlet and not less than the combined area of the flue outlets for which it acts as a common connector ?


Photo Comment

3. Are vent connector clearances to combustibles in compliance with the manufacturer’s listing or performance standards ?


Photo Comment

4. Is it verified that single-wall vents do not penetrate a wall, floor, or ceiling without a listed pass-through assembly, except for gas vents, which are allowed for exterior combustible walls only with a “ventilated metal thimble” ?


Photo Comment

5. Are vent terminations installed following the manufacturer’s listing ?


Photo Comment

6. For exhaust vent terminations for mechanical draft and direct venting, is the termination not less than 4 feet below or 4 feet horizontally from, and not less than 1 foot above a door, an operable window, or a gravity air inlet into a building, and not less than 3 feet above any forced air intake within 10 feet or within 12 inches of grade ?


Photo Comment

7. Are specifications for gas vent terminations for listed caps for roof or wall size and clearances—see Table G2427.6.4 less than 12 inches, and not less than 8 feet from vertical wall or obstruction terminates above roof per table (pitch of roof)? Are gas vents more than 12 inches terminate 2 feet above, and 10 feet away from any portion of a building?


Photo Comment

8. Is it ensured that vent terminals (except for direct vent) are not mounted directly above or within 3 feet horizontally of a gas meter or oil tank vent ?


Photo Comment

9. Are vent terminals positioned no closer than 3 feet to an interior corner formed by two perpendicular walls ?


Photo Comment

10. For power exhaust terminals, are they not located within 10 feet of property lines and adjacent buildings and at least 7 feet above any finished ground-level public walkway ?


Photo Comment

11. Is it verified that venting systems do not extend into or pass through any fabricated air duct or furnace plenum ?


Photo Comment

12. Are chimneys or vent connectors not passing through floors, walls, ceilings, or partitions unless the connector is listed and labeled for wall pass-through and installed per the listing (M1803.3.1; G2427.7.6)?


Photo Comment

13. Where vents extend into an attic and pass through insulated assemblies, is an insulation shield of 26 gage sleeve not less than 2 inches above the insulation, to provide clearance between the vent and combustible insulation materials ?


Photo Comment

14. Is venting supported following the manufacturer’s listing ?


Photo Comment
Clothes Dryer

1. Is the clothes dryer exhausted following the manufacturer’s instructions )?


Photo Comment

2. Are the clothes dryer exhaust ducts made of metal with smooth interior surfaces, and do the joints run in the direction of airflow ?


Photo Comment

3. Has a protective shield of steel plates been installed in areas where nails or screws may penetrate the clothes dryer exhaust duct, including at framing members less than 1-1/4 inches between the duct and finished face of the framing member and extend not less than 2 inches above the sole plate and beyond the top plate?


Photo Comment

4. Are screws used as fasteners for the clothes dryer exhaust duct, and do they not protrude more than 1/8 inch?


Photo Comment

5. Is the duct connector for the clothes dryer a minimum of 4 inches or is the appliance outlet size?


Photo Comment

6. For determining dryer duct length, does the exhaust duct not exceed 35 feet, with deductions of 2-1/2 feet for each 45-degree elbow and 5 feet for each 90-degree bend for elbows, or is it determined based on the manufacturer’s installation instructions when the make and model of the dryer are provided to the Code Official at rough-in ?


Photo Comment

7. Does the clothes dryer ducting run independently of other ducted systems, and does it convey moisture to the outdoors (except for listed and labeled condensing ductless clothes dryers) ?


Photo Comment

8. Does the exterior termination for the clothes dryer exhaust duct have a backdraft damper with no screens, and is it at least 3 feet away from any openings into the building, and does it not connect to vent connectors, vents, or chimneys ?


Photo Comment

9. If the clothes dryer ducting is concealed in construction exceeding 35 feet, has it been labeled with the equivalent length, located within 6 feet of the exhaust connection ?


Photo Comment

10. Is the dryer exhaust duct installed at the time of occupancy, or if the dryer is not installed, has the exhaust duct been capped at the location of the future dryer (except for listed and labeled condensing ductless clothes dryers) ?


Photo Comment

11. Is the dryer transition duct a single length, listed and labeled to UL 2158A, and a maximum of 8 feet long, and is it not concealed within construction ?


Photo Comment

12. If it's a gas dryer, is the gas connector a maximum of 6 feet long, measured along the centerline of the connector; and has one connector only?


Photo Comment

13. Is the gas shutoff valve installed immediately ahead of the connector?


Photo Comment
Range

1. Is there a vertical clearance to combustibles of at least 30 inches or per the manufacturer’s listing, with the minimum clearance reduced to 24 inches for gas cooking appliances under one of three exceptions ?


Photo Comment

2. Is the gas connector a maximum of 6 feet in length?


Photo Comment

3. Has a shutoff valve been installed immediately ahead of the gas connector ?


Photo Comment
Range Hood

1. Does the range hood terminate outside, is it airtight, equipped with a backdraft damper, and independent of all other exhaust systems ?


Photo Comment

2. If the hood has an exhaust rate over 400 CFM, has it been provided with makeup air at a rate approximately equal to the exhaust air rate unless all fuel-burning appliances are direct-vent or use a mechanical draft venting system with at least one damper ?


Photo Comment

3. Is the ducting for the range hood made of galvanized steel, stainless steel, or copper, with a smooth interior, or if it's a domestic cooking appliance equipped with a downdraft exhaust system, is it compliant with exceptions related to schedule 40 PVC ?


Photo Comment

4. For domestic open-top broiler units, does the metal exhaust hood have a minimum thickness of 0.0157 inches, with a 1/4-inch clearance between the hood and the underside of combustible materials or cabinets, and is there a minimum clearance of 24 inches between the cooking surface and combustible materials or cabinets, unless the broiler unit is listed and labeled for use with an integral exhaust system ?


Photo Comment

5. Is the width of the hood not less than the width of the broiler unit, and does it extend over the entire unit? If it's located inside the building envelope, does it discharge to the outdoors and have a backdraft damper or other means to control infiltration/exfiltration when not in operation?


Photo Comment

6. Are broiler units incorporating an integral exhaust system, and listed and labeled for use without an exhaust hood, or broiler units permanently installed outside the building envelope and with the cooking surface at least 5 feet below a 1-hour fire resistance rated ceiling, exempt from having an exhaust hood?


Photo Comment
Fireplace

1. Are factory-built fireplaces certified, listed, and labeled in accordance with ASTM E2558? Was testing performed by the Washington State Department of Energy (DOE) and a US EPA-accredited laboratory ?


Photo Comment

2. Are certified masonry and concrete fireplaces and heaters tested and certified to Washington State Building Code Standard 31-2? Was testing performed by the Washington State DOE and a US EPA-accredited laboratory?


Photo Comment

3. For solid fuel-burning appliances and fireplaces, do they have tight-fitting metal or ceramic doors and certification to test No. 11-Negative pressure test, Section 12.3, of ULCS627-M1984 for outside combustion air, with ducts ranging from 4 inches minimum to 20 feet maximum in length (R1006.6, as amended by Washington State)?


Photo Comment

4. Do hearth extensions comply with the fireplace listing and are readily distinguishable from the surrounding floor ?


Photo Comment

5. If decorative gas fireplaces are installed in a solid fuel-burning fireplace, were they installed per the manufacturer’s installation instructions ?


Photo Comment

6. Are appliance shutoff valves located in the same room as the fireplace and within 6 feet of the appliance? If they are located in the fireplace firebox, were they installed per the appliance manufacturer’s instructions? Shutoff valves for vented decorative appliances and room heaters shall be permitted to be installed in a remote area from the appliance with ready access, permanent identification, and serving no other appliance. If a shutoff valve is installed at a manifold, within 50 feet of the appliance, does it comply with specific requirements ?


Photo Comment

7. Are decorative shrouds used at chimney terminations listed and labeled for use with the specific chimney system ?


Photo Comment
Air Conditioning

1. Are cooling coils installed downstream (on the return side) from the heat exchanger ?


Photo Comment

2. Does the working space for air conditioning equipment meet the minimum requirement of 30 inches by 30 inches ?


Photo Comment

3. Is the condensate disposal line directed to an approved place of disposal, avoiding public streets, and alleys, or creating a nuisance ?


Photo Comment

4. Are auxiliary and secondary drain systems (including pan) in addition to condensate disposal, where damage to any building components occurs from overflow or stoppage of condensate drain piping (four methods, including UL 508 shutoff switch)?


Photo Comment

5. Is the condensate line for the air conditioning system at least 3/4 inch in diameter and sloped to drain termination without sags; 1/8 unit in 12 units (1-percent slope?


Photo Comment

6. Do the refrigerants use conform to ANSI/ASHRAE 34 standards ?


Photo Comment

7. Are refrigerant lines insulated to a minimum of R-4, with a maximum perm rating of 0.05 ?


Photo Comment

8. Are the refrigerant circuit access ports fitted with tamper-resistant caps ?


Photo Comment
Exhaust Venting

1. Are source-specific ventilation fans installed in accordance with Table as amended by Washington State, in kitchens, bathrooms, and water closet rooms?


Photo Comment

2. Do bathroom exhaust fans provide a minimum of 50 cubic feet per minute (CFM) or 20 CFM continuously, and kitchen fans provide a minimum of 100 CFM or 30 CFM continuously?


Photo Comment

3. Are all exhaust ducts installed to terminate outside the building and equipped with backdraft dampers? Is insulation provided to a minimum of R-4 in unconditioned spaces, such as attics and crawlspaces ?


Photo Comment
Whole House Ventilation Systems

1. Have whole-house mechanical ventilation systems been installed in each dwelling unit in compliance with ? Are these systems set to operate continuously at the minimum ventilation rate as determined by unless configured with intermittent off controls?


Photo Comment
Energy Code Requirements

1. Have the approved plans specified the types of heating and cooling equipment and their associated efficiency requirements, as well as any energy credits required?


Photo Comment

2. Is the duct rough-in test affidavit available on-site for inspection? Does it confirm that the maximum duct leakage is 4 CFM per 100 square feet with an air handler installed or 3 CFM per 100 square feet without the air handler ?


Photo Comment

3. Have building framing cavities been avoided for use as ducts or plenums? Are ducts installed in exterior walls, floors, and ceilings without displacing required envelope insulation ?


Photo Comment

4. For ducts located in conditioned spaces, are they either completely within the continuous air barrier and building thermal envelope, or do all heating, cooling, and ventilation system components be installed inside the conditioned space including, but not limited to, forced air ducts, hydronic piping, hydronic loops, convectors and radiators where combustion equipment is direct vent or sealed combustion?


Photo Comment

5. For forced air ducts, is a maximum of 10 linear feet of return ducts and 5 linear feet of supply ducts permitted to be located outside the conditioned space, provided they are insulated to a minimum of R-8?


Photo Comment

6. Are ducts outside the building thermal envelope insulated to a minimum of R-8, and ducts within a concrete slab or in the ground insulated to R-10 with insulation designed for below-grade use?


Photo Comment

7. Have HVAC supply and return register boots been properly sealed to the subfloor, wall covering, or ceiling that they penetrate, following the guidelines in WSEC Table ?


Photo Comment

8. For all detached one- and two-family dwellings and multiple single-family dwellings (townhouses) up to three stories in height above the grade plane, have inverter-driven ductless mini-split heat pumps been installed in the largest zone as the primary source of electric zonal heating, as required by?


Photo Comment

9. In cases where there is a heated slab on the grade floor, has the entire area been thermally isolated from the soil with a minimum of R-10 insulation, as specified in WSEC ?


Photo Comment

10. For the project, have additional energy efficiency requirements (energy credits) been met according to the following criteria, • Small Dwelling Unit: 3.0 credits - for dwelling units less than 1500 square feet in conditioned floor area with less than 300 square feet of fenestration area, or for additions to existing buildings greater than 500 square feet of heated floor area but less than 1500 square feet. • Medium Dwelling Unit: 6.0 credits - for all dwelling units that do not fall under Options 1, 3, or 4. • Large Dwelling Unit: 7.0 credits. • Dwelling units serving R-2 occupancies: 4.5 credits. • Additions less than or equal to 500 square feet: 1.5 credits .


Photo Comment

11. Have the drawings included with the building permit application identified which options have been selected and the point value of each option, regardless of whether separate mechanical, plumbing, electrical, or other permits are utilized for the project?


Photo Comment

Is this sample what you are looking for?
Sign up to use & customise this template, or create your own custom checklist:

Checklist by GoAudits.com – Please note that this checklist is intended as an example. We do not guarantee compliance with the laws applicable to your territory or industry. You should seek professional advice to determine how this checklist should be adapted to your workplace or jurisdiction.

goaudits app

Get started on a free trial

Seeing is believing! Try the full platform FREE for 14 days with your own data.
Or ask us to setup the system for you, at no cost.