FINISHED BASEMENT CONSTRUCTION

Helpful Hints for Finishing a Basement Area to Habitable Space

 

R302.5 Dwelling-Garage Opening and Penetration Protection
Openings and penetrations through the walls or ceilings separating the dwelling from the garage shall be in accordance with Sections R302.5.1 through R302.5.3.

R302.5.1 Opening Protection
Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 13/8 inches in thickness, solid or honeycomb-core steel doors not less than 13/8 inches thick, or 20-minute fire-rated doors. Doors shall be self-latching and equipped with a self-closing or automatic-closing device.

R302.11 Fireblocking
In combustible construction, fireblocking shall be provided to cut off both vertical and horizontal concealed draft openings and to form an effective fire barrier between stories, and between a top story and the roof space.

Fireblocking shall be provided in wood-framed construction in the following locations:

  1. In concealed spaces of stud walls and partitions, including furred spaces and parallel rows of studs or staggered studs, as follows:

1.1. Vertically at the ceiling and floor levels.

1.2. Horizontally at intervals not exceeding 10 feet.

 

  1. At interconnections between concealed vertical and horizontal spaces such as occur at soffits, drop ceilings, and cove ceilings.
  2. In concealed spaces between stair stringers at the top and bottom of the run. Enclosed spaces under stairs shall comply with Section R302.7.
  3. At openings around vents, pipes, ducts, cables and wires at ceiling and floor level, with an approved material to resist the free passage of flame and products of combustion. The material filling this annular space shall not be required to meet the ASTM E136 requirements.
  4. For the fireblocking of chimneys and fireplaces, see Section R1003.19.
  5. Fireblocking of cornices of a two-family dwelling is required at the line of dwelling unit separation

R302.11.1 Fireblocking Materials
Except as provided in Section R302.11, Item 4, fireblocking shall consist of the following materials.

  1. Two-inch nominal lumber.
  2. Two thicknesses of 1-inch nominal lumber with broken lap joints.
  3. One thickness of 23/32-inch wood structural panels with joints backed by 23/32-inch wood structural panels.
  4. One thickness of 3/4-inch particleboard with joints backed by 3/4-inch particleboard.
  5. One-half-inch gypsum board.
  6. One-quarter inch cement-based millboard.
  7. Batts or blankets of mineral wool or glass fiber or other approved materials installed in such a manner as to be securely retained in place.
  8. Cellulose insulation installed as tested in accordance with ASTM E119 or UL 263, for the specific application.

 

R302.12 Draftstopping

In combustible construction where there is usable space both above and below the concealed space of a floor-ceiling assembly, draftstops shall be installed so that the area of the concealed space does not exceed 1,000 square feet. Draftstopping shall divide the concealed space into approximately equal areas. Where the assembly is enclosed by a floor membrane above and a ceiling membrane below, draftstopping shall be provided in floor-ceiling assemblies under the following circumstances:

  1. Ceiling is suspended under the floor framing.
  2. Floor framing is constructed of truss-type open-web or perforated members.

 

R302.12.1 Materials
Draftstopping materials shall be not less than 1/2-inch gypsum board, 3/8-inch wood structural panels or other approved materials adequately supported. Draftstopping shall be installed parallel to the floor framing members unless otherwise approved by the building official. The integrity of the draftstops shall be maintained.

R303.10 Required Heating
Where the winter design temperature in Table R301.2 is below 60°F, every dwelling unit shall be provided with heating facilities capable of maintaining a room temperature of not less than 68°F at a point 3 feet above the floor and 2 feet from exterior walls in habitable rooms at the design temperature. The installation of one or more portable space heaters shall not be used to achieve compliance with this section.

R305.1 Minimum Height                                                                                                               Existing basements being converted to habitable space shall have a ceiling height of not less than 6 feet 8 inches.

R305.1.1 Basements
Portions of basements that do not contain habitable space or hallways shall have a ceiling height of not less than 6 feet 8 inches.

R302.7 Under-Stair Protection
Enclosed space under stairs that is accessed by a door or access panel shall have walls, under-stair surface and any soffits protected on the enclosed side with 1/2-inch gypsum board.

R310.2 Emergency Escape and Rescue Openings

R310.2.1 Minimum Size                                                                                                                                              Emergency escape and rescue openings shall have a net clear opening of not less than 5.7 square feet.
Exceptions:

  1. Grade floor openings or below grade openings shall have a net clear opening of not less than 5 square feet.
  2. Existing buildings undergoing alterations or installation of replacement windows shall be permitted to utilize removable sash to achieve the required minimum net clear openings. Such removable sash shall be capable of being removed without the use of a key or tool.

R310.2.2 Minimum Dimensions
The minimum net clear opening height dimension shall be 24 inches. The minimum net clear opening width dimension shall be 20 inches. The net clear opening dimensions shall be the result of normal operation of the opening.

R310.2.3 Maximum Height From Floor
Emergency escape and rescue openings shall have the bottom of the clear opening not greater than 44 inches above the floor.
Exception: The 44-inch maximum sill height shall be permitted to be measured vertically above a fixed, permanent platform, step or steps whose minimum width shall equal or exceed the operable width of the opening and shall be centered on such opening and which shall comply with Sections R311.7.5.1(The riser height shall be not more than 81/4 inches) and R311.7.5.2 (The minimum tread depth shall be 9 inches). Glazing in windows complying with this exception shall not be subject to the provisions of Section R308.4.6 orR308.4.7.

R310.2.4 Emergency Escape and Rescue Openings Under Decks, Porches and Cantilevers
Emergency escape and rescue openings installed under decks, porches and cantilevers shall be fully openable and provide a path not less than 36 inches in height and 36 inches in width to a yard or court.

R310.3 Emergency Escape and Rescue Doors
Where a door is provided as the required emergency escape and rescue opening, it shall be a side-hinged door or a sliding door.

                                                                                                                                                                                           R311.6 Hallways
The width of a hallway shall be not less than 3 feet.

R314 Smokes                                                                                                                                                                                   Smoke and Carbon Monoxide detectors are required.

R311.7 Stairways

R311.7.1 Width
Stairways shall not be less than 36 inches in clear width at all points above the permitted handrail height and below the required headroom height. The clear width of stairways at and below the handrail height, including treads and landings, shall not be less than 311/2 inches where a handrail is installed on one side and 27 inches where handrails are provided on both sides.
Exceptions: 

  1. The width of spiral stairways shall be in accordance with Section R311.7.10.1.
  2. The width of existing stairways serving existing unfinished attics or existing unfinished basements being converted to habitable space or replacement stairways within existing dwellings shall not be less than 32 inches in clear width at all points above the permitted handrail height and below the required headroom height. The clear width of stairways at and below the handrail height, including treads and landings, shall not be less than 28 inches where a handrail is installed on one side and 24 inches where handrails are provided on both sides.
  3. Where an incline platform lift or stairway chairlift is installed on a stairway within a dwelling unit, a clear passage width not less than 20 inches shall be provided. If the seat and platform can be folded when not in use, the distance shall be measured from the folded position.

 

R311.7.5.1 Risers
The riser height shall be not more than 81/4 inches. The riser shall be measured vertically between leading edges of adjacent treads. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch. Risers shall be vertical or sloped from the underside of the nosing of the tread above at an angle not more than 30 degrees from the vertical. Open risers are permitted provided that the opening between treads does not permit the passage of a 4-inch-diameter sphere.
Exceptions:

  1. The maximum riser height of existing stairs serving existing unfinished attics or existing unfinished basements being converted to habitable space or replacement stairs where the pitch or slope cannot be reduced because of existing construction shall be 9 inches, measured in accordance with Section R311.7.5.1.
  2. The opening between adjacent treads is not limited on spiral stairways.
  3. The riser height of spiral stairways shall be in accordance with Section R311.7.10.1.


R311.7.5.2 Treads
The minimum tread depth shall be 9 inches. The tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread's leading edge. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than 3/8 inch.
Exception: The minimum tread depth of existing stairs serving existing unfinished attics or existing unfinished basements being converted to habitable space or replacement stairs within existing dwellings shall be 8 inches, measured in accordance with Section R311.7.5.2.

R311.7.8 Handrails
Handrails shall be provided on not less than one side of each flight of stairs with four or more risers.


R311.7.8.1 Height
Handrail height, measured vertically from the sloped plane adjoining the tread nosing, or finish surface of ramp slope, shall be not less than 34 inches (864 mm) and not more than 38 inches.
Exceptions:

  1. The use of a volute, turnout or starting easing shall be allowed over the lowest tread.
  2. Where handrail fittings or bendings are used to provide continuous transition between flights, transitions at winder treads, the transition from handrail to guard, or used at the start of a flight, the handrail height at the fittings or bendings shall be permitted to exceed 38 inches.


R311.7.8.2 Handrail Projection
Handrails shall not project more than 41/2 inches on either side of the stairway.
Exception: Where nosing’s of landings, floors or passing flights project into the stairway reducing the clearance at passing handrails, handrails shall project not more than 61/2 inches into the stairway, provided that the stair width and handrail clearance are not reduced to less than that required.

R311.7.8.3 Handrail Clearance
Handrails adjacent to a wall shall have a space of not less than 11/2 inches between the wall and the handrails.

 

R311.7.8.4 Continuity
Handrails shall be continuous for the full length of the flight, from a point directly above the top riser of the flight to a point directly above the lowest riser of the flight. Handrail ends shall be returned toward a wall, guard walking surface continuous to itself, or terminate to a post.
Exceptions:

  1. Handrail continuity shall be permitted to be interrupted by a newel post at a turn in a flight with winders, at a landing, or over the lowest tread.
  2. A volute, turnout or starting easing shall be allowed to terminate over the lowest tread and over the top landing.


R311.7.8.5 Grip Size
Required handrails shall be of one of the following types or provide equivalent graspability.

  1. Type I. Handrails with a circular cross section shall have an outside diameter of not less than 11/4 inches and not greater than 2 inches. If the handrail is not circular, it shall have a perimeter of not less than 4 inches and not greater than 61/4 inches and a cross section of not more than 21/4 inches. Edges shall have a radius of not less than 0.01 inch.
  2. Type II. Handrails with a perimeter greater than 61/4 inches shall have a graspable finger recess area on both sides of the profile. The finger recess shall begin within 3/4 inch  measured vertically from the tallest portion of the profile and have a depth of not less than 5/16 inch within 7/8 inch below the widest portion of the profile. This required depth shall continue for not less than 3/8 inch to a level that is not less than 13/4 inches below the tallest portion of the profile. The width of the handrail above the recess shall be not less than 11/4 inches and not more than 23/4 inches. Edges shall have a radius of not less than 0.01 inch.

 

R311.7.9 Illumination
Stairways shall be provided with illumination in accordance with

Section R303.7                                                                                                                               Interior stairways shall be provided with an artificial light source to illuminate the landings and treads. The light source shall be capable of illuminating treads and landings to levels of not less than 1 footcandle as measured at the center of treads and landings. There shall be a wall switch at each floor level to control the light source where the stairway has six or more risers. Exception: A switch is not required where remote, central, or automatic control of lighting is provided.

SectionR303.8.Exterior Stairway Illumination
Exterior stairways shall be provided with an artificial light source located at the top landing of the stairway. Exterior stairways providing access to a basement from the outdoor grade level shall be provided with an artificial light source located at the bottom landing of the stairway.

                                                                                                                                                                                              INSULATION                                                                                                                                                                                               

Minimum R-15 Insulation is required in interior walls of basement

SILL PLATES                                                                                                                                                               

Pressure treated wood sleepers and/or sill plates are to be used when in contact with Concrete.

 COMBUSTION AIR                                                                                                                             

Combustion air for heating appliances shall be per Section M1701 Solid fuel-burning appliances shall be provided with combustion air in accordance with the appliance manufacturer's installation instructions. Oil-fired appliances shall be provided with combustion air in accordance with NFPA 31. The methods of providing combustion air in this chapter do not apply to fireplaces, fireplace stoves and direct-vent appliances. The requirements for combustion and dilution air for gas-fired appliances shall be in accordance with Chapter 24.         

ELECTRICAL                                                                                                                                                                          

 When finishing the basement area, it’s important that a space be maintained around the Electrical service panel.  3’ in front, 30” left to right and 6-1/2’ in height.                                                                                                   

All existing and new electrical circuits to be Arc Fault protected.                                                                                          

All Receptacles 125 and 250 volts shall be GFI protected.                                                                                                                                          

All 15 and 20 amp, 125 and 250 volt non locking type receptacles to be tamper resistant.      

 

This may not be a complete list.  Please contact the Woodbury Building Department if you should have any questions.