NEWS LETTER MARCH 27, 2009

Transcription

1 PLANNING, BUILDING & DEVELOPMENT SERVICES DEPARTMENT Street S.E. Medicine Hat, Alberta T1A 8E6 Telephone: FAX NEWS LETTER MARCH 27, 2009 GENERAL As you are probably aware there has been a major code change in relation to fire ratings, spatial separations, limiting distances and wall cladding material. These changes come into effect on May 3, Any plans submitted after May 3 rd, 2009 will be reviewed based on the new standards. Permit applications submitted prior to May 3 rd need only meet the requirements of the pre-existing code. Once the plans review has been completed and the permit issued, construction MUST commence within three months of the permit issuance date. You will find there have been major changes to limiting distances (setbacks from side yard property lines) and the percentage of unprotected openings (windows) of actual wall area. We had anticipated these upcoming code changes and had initiated check lists for commercial and residential construction. The designer must ensure window openings, setbacks, and the wall finish material is clearly identified on their plans. Code requirements for the design specifics must be referenced. Following is a list of the code changes. We have tried to simplify it so it makes for easier reading. BUILDING THE FOLLOWING CONDITIONS APPLY TO PART 3 BUILDINGS OF RESIDENTIAL, COMMERCIAL, INDUSTRIAL, ASSEMBLY AND INSTITUTIONAL OCCUPANCIES. PART 9 REQUIREMENTS WILL FOLLOW LATER IN THIS NEWS LETTER. UNPROTECTED OPENINGS IN WALLS: Individual unprotected openings (windows) in walls 2 metres or less from the side yard property line (or in rare instances the rear property line) cannot exceed: 1).35 sq. m. in glass area where the limiting distance 1.2 m. 2).78 sq. m. in glass area where the limiting distance is 1.5m. 3) 1.88 sq. m. in glass area where the limiting distance is 2.0 m. 4) No unprotected openings are allowed in walls where the limiting distance is less than 1.2 m. If the building is sprinklered or there is greater than a two metre limiting distance the above conditions do not apply. The requirements for maximum glass coverage of wall area as identified

2 2 in tables A & B must still be met (tables have not changed from previous code). Individual window openings in the same wall assembly MUST be separated not less than 2m both horizontally and vertically (when located in the same fire compartment- not separated with fire rated walls or ceilings ). Exceptions to this clause are: 1) The building is sprinklered throughout, OR 2) The limiting distance is 2 metres or more. 3) This sentence applies to windows that are located in the same fire compartment. An individual window described in sentence 1 & 2 shall be separated 2 m horizontally from other windows on the same floor level. The windows of the floor level(s) above must be separated 2 m vertically from the windows below. If these windows are in separate fire compartments (different suites with fire rated separations) the requirements of sentence 3 do not apply. 4) Stacked windows are allowed if they occur on the same floor level. 5) If the windows are less than two metres apart (horizontally) there must be a partition (wall) between them that extends not less than 1.5 metres in from the exterior wall (floor to ceiling height with conventional ½ gypsum board or another acceptable finish). COMPONENTS OF EXTERIOR WALLS AND EXPOSING BUILDING FACES Combustible wall material is acceptable in non-combustible construction when used in non-load bearing exterior walls that have maximum unprotected window openings of less than 10% (of wall area). The provision is: The building must be not more than three storeys in building height OR sprinklered throughout. These walls must have a thermal barrier and be fire rated in conformance with CAN/ULC-S134. Table (minimum required fire resistance ratings of exterior walls) has been revised as has the code standards. A simple interpretation of the standards follows: 1) Claddings for buildings or fire compartments where the area of unprotected openings is more than 10% of the wall area need not be non-combustible providing they conform to CAN/ULC- 134 and meet the requirements & 3 (heat flux for flame exposure to exterior walls). 2) Claddings for buildings or fire compartments where the area of unprotected openings is more than 25% but less than 50% of the wall area need not be non-combustible where the limiting distance is more than 5 metres AND the building or fire compartment is sprinklered. The cladding can consist of lumber siding, lumber shakes, plywood, osb, wafer board, or vinyl siding All of the above sidings must be installed in conjunction with exterior 12.7 mm thick gypsum board. The gypsum board must be installed on the full exterior surface of the wall(s) prior to the finish material being applied. Ensure proper nailing procedures are used as gypsum board is not approved for the attachment of cladding materials. Other acceptable materials are accelerated weathered fire retardant treated wood conforming to ASTM D 2898 (with a flame spread rating of less than 25) or other materials with flame spread ratings of less than 25 that conform to CAN/ULC-S102.2.

3 3 If exterior foam plastic insulation is used on the exterior wall of a building more than three storeys in building height it must be protected with concrete or masonry not less than 25 mm thick OR non-combustible materials tested and approved to conform with CAN/ULC-S101. The requirement applies to walls of buildings with unprotected openings of more than 10% of wall area. The requirement is waived only if all the requirements of are met refers to buildings 3 storeys or less in height or are sprinklered The maximum area of unprotected openings in the exposing wall of an unsprinklered building can be doubled if ALL the openings are glazed with glass block or wired glass in rated frames conforming to NFPA80. There is a catch to this. The walls in which they are located must have a fire rating of not more than 1 hour. They will obviously only be approved if installed in building where the required fire rating is one hour or less. COMBUSTIBLE PROJECTIONS Combustible projections on the exterior of a wall that are more than 1metre above the ground shall not be permitted within: 1) 1.2 m of a property line or centre line of a public way. 2) 2.4 m of a combustible projection or wall of another building on the site. Roof overhangs are not permitted where they are less than.45m from the property line. Roof overhangs that are less than 1.2 m from the property line shall be protected. There shall be no openings in the soffit and both the soffit and fascia must be protected with one of the following materials: 1) 28 gauge mild or stainless steel 2) 26 gauge unvented soffit and fascia 3) 30 gauge galvanized steel 4) 12.5mm gypsum board (exterior) 5) 11mm plywood with all edges supported and protected with caulking, 6) 12.5 mm osb or waferboard with all edges supported and caulked 7) 11mm lumber free of knots. SPRINKLER PROTECTION Residential occupancies up to including four storey of building height which of a size that require they be sprinklered must conform with the following conditions. Sprinklers are required in the following locations: 1) Porches and balconies. Closets and storage rooms on these balconies. 2) Public corridors 3) Stairs which are open and attached. 4) Attics and floor/ceiling spaces. 5) Penthouse equipment rooms 6) Elevator machine rooms 7) Concealed spaces dedicated exclusively to and containing only dwelling unit ventilation equipment. 8) Crawl spaces 9) Other concealed spaces that are not used or intended for living purposes or storage and do not contain fuel fired appliances.

4 4 The exceptions to the above clause are: 1) Non-combustible or limited combustible concealed spaces with no access. 2) Non-combustible or limited combustible concealed spaces with limited access that contain no occupancy. The space cannot be used for the storage of any combustible material. 3) Concealed spaces formed by studs or joists with less than 6 between the inside or outside edges. 2 x 6 joists with the ceiling membrane (fire rated drywall) installed directly to the bottom of the joists. 4) Concealed spaces formed by composite wood joist construction with ceilings attached directly to the bottom chord or to metal channels not than 1 in thickness. The area cannot exceed 160 ft3 (4.53 m3) or the joist channels must be firestopped using materials equivalent to the web construction. Not less than 3 ½ of batt insulation must be installed at the bottom of the joist channels. 5) Concealed spaces formed by composite wood joist construction. Wood I beams must be constructed with wood flanges and solid wood webs. 6) Concealed spaces completely filled with non-combustible insulation (mineral wool). 7) Concealed spaces with an upper composite wood joist construction and lower wood joist construction. The lower wood joist assembly must be filled with non-combustible insulation and the upper composite wood joists must be compartmentalized in fire compartments not exceeding 160 ft3 (4.53 m3). The full depths of the joists must have material equivalent to the web construction. 8) Concealed spaces over isolated small rooms not exceeding 55 ft2 (4.6m2). 9) Concealed spaces where rigid materials are used and exposed surfaces have a flame spread rating of 25 or less and the materials have been demonstrated not to propagate fire need not be sprinklered. 10) Concealed spaces constructed of fire retardant treated wood defined by NFPA ) Noncombustible concealed spaces having exposed combustible insulation where the heat content of the face and substrate of the insulation material does not exceed 1000 Btu/ft2. 12) Concealed ceiling spaces below insulation that is laid directly on top of or within the ceiling joists in combination with a sprinklered attic. 13) Sprinkler protection is not required in vertical pipe chases under 10 ft2 (.93 m2) in area, where provided in multi-floor buildings. Fire stopping must be provided at each floor level and the chase cannot contain a source of ignition. All piping must be noncombustible. 14) Exterior columns under 10 ft2 in area formed by studs or wood joists, supporting exterior canopies that are fully sprinklered..

5 5 PART 9 BUILDINGS (TRI-PLEXES & LARGER) THE FOLLOWING REQUIREMENTS APPLY TO RESIDENTIAL OCCUPANCIES CONTAINING MORE THAN TWO DWELLING UNITS, ARE TWO STOREYS OR MORE IN BUIDING HEIGHT, ARE NOT SPRINKLERED, AND HAVE DWELLING UNITS IN PART OR WHOLE OVER OTHER DWELLING UNITS. BALCONIES Balcony walls MUST be protected the full width of the balcony and 1.2 m to either side. The exterior claddings can consist of brick, concrete/asbestos tiles/sheets, or stucco not less then 19mm thick. Combustible claddings can also be used if installed over ½ gypsum board. The list of the acceptable claddings are noted on page 2 of this news letter (see ). Obviously this will create problems when comes to windows in close proximity to the deck. Your designer will have to take this into consideration in his/her design. If there are roofs or ceilings above the balconies they too must be protected. The easiest way of achieving this is the installation of ½ gypsum board to the underside of the roof joists. All joints must be taped and mudded. It is recommended 26 gauge unvented soffit be used as final finish. There are other finishes such as concrete or asbestos sheets which can be used. LIMITING DISTANCES AND UNPROTECTED OPENINGS Where there is a limiting distance of more than 2 m (distance the building is to the property line) there are no restrictions as to exterior wall protection, roof overhangs and cantilever projections based on the assumption the cantilevers and roof overhangs will not project from the wall more than 2 0. There is no restriction on individual window size providing the maximum unprotected glass area does not exceed that which is allowed in table A. Where there are skewed walls in relation to the property line (cantilevers, bays, fireplace chases, or the house wall is angled to the property line on a pie shaped lot) the distance to property line must be measured from a vertical plane (measured horizontally to the property line from the vertical plane of the projection). If there is a window in the face of the projection, the size must comply with table (as a percentage of the wall area of the projection). Allowable glass area will be relatively small depending upon the actual limiting distance. Unprotected openings (windows) are not allowed in walls that are less than 1.2 m from the property line UNLESS they are protected with fire shutters that have the same fire rating as the wall assembly. New table B The maximum size of each individual unprotected opening cannot exceed: 1) 0.35m2 - walls that are 1.2 m from the property line. 2) 0.78m2 - walls that are 1.5 m from the property line. 3) 1.88m2 - walls that are 2.0 m from the property line. Each individual unprotected opening as described in B shall be separated by not less than 2 m horizontally and 2 m vertically from any other unprotected opening that is located in the same wall and within the same fire compartment. Walls that are in different fire compartments (different suites) which are less than 2 m apart (for the purpose of this clause) are exempt from this requirement. Windows that are in the same suite must comply.

6 6 Other exceptions are: 1) Stacked windows, on same floor level, are acceptable. 2) Two windows can be located less than 2m apart if they are separated with a floor to ceiling wall that extends not less than 1.5m (5 0 ) into the house. The wall must be protected with ½ gypsum board or another equivalent finish material. Exterior gable end walls that enclose an attic or roof space must comply with the same requirements as that which is required of exterior wall finishes. See revised table (1). Claddings on exposed building faces and exterior walls above exposing building faces that enclose attic or roof spaces for buildings or fire compartments where the permitted maximum aggregate area of unprotected openings is more than 10% of the building face need not be non-combustible where the wall assembly satisfies the criteria of sentences (2) & (3) (flaming and heat flux) when subjected to CAN/ULC-S134 (fire tests for exterior wall assemblies). Claddings on exposed building faces and exterior walls above exposing building faces that enclose attic or roof spaces for buildings or fire compartments where the permitted aggregate area of unprotected openings is more than 25% but less than 50% of the building face need not be non-combustible if the limiting distance is more than 5 m AND the building or compartment is sprinklered OR the cladding conforms to (3) (C) or (D) (see page 2 of this news letter for acceptable finishes). Combustible projections on exterior walls that are more than 1 m above ground level and could expose an adjacent building to fire spread are NOT permitted within 1.2 m of the property line or 2.4 m of any building or projection of a building on the same property. Roof overhangs are not permitted within.45m of the property line. Where the roof projection is less than 1.2m but more than.45m the soffit shall have no openings and be protected with one of the following materials. 1) 28 gauge mild or stainless steel 2) 26 gauge unvented soffit and fascia 3) 30 gauge galvanized steel 4) 12.5 mm gypsum board (exterior grade) 5) 11 mm plywood with all edges supported and caulked 6) 12.5 mm osb or waferboard with all edges supported and caulked 7) 11mm lumber free of knots. ATTACHED GARAGES Walls and ceilings of attached garages that separate one unit from another must still be fire rated. Walls and ceilings of attached garages that do not serve as part of the fire resistance ratings must be provided with thermal insulation conforming with of the building code. Wall insulation must be R12 minimum. The ceilings of attached garages must have R34 minimum or R20 if there is a bonus room or bedroom above. The walls and ceilings of the garage must have an interior finish of 12.7mm (½ ) gypsum board, plaster and lathe or another approved material that has a fire resistance rating of at least 15 minutes. OSB does not meet this requirement. RESIDENTIAL SINGLE FAMILY DWELLINGS AND DUPLEXES This section applies to: 1) Single family dwellings 2) Buildings that contain detached garages or accessory buildings facing a dwelling unit, and the detached garage or accessory building serves one dwelling unit or the secondary suite of the dwelling unit. The accessory building must be on the same property as the dwelling unit and the dwelling unit must be the only major occupancy on the property.

7 7 3) Buildings that contain one dwelling unit located in whole or part above another dwelling unit. There can be no more than two dwelling units and the building height cannot exceed three storeys in height including the basement. AREA AND LOCATION OF EXPOSING BUILDING FACES There are no special requirements for wall finishes and individual window sizes if a limiting distance is 2 m or more (distance from the wall of the house to the side property line). This is working on the assumption that the roof overhang and any cantilevered projection will extend no more than 2 0 out from the house. The maximum area of unprotected openings must still meet the requirements as listed in table The catch to this clause is any portion of the wall that is less than 2m from the property line must still meet the maximum glazed area requirement as a percentage of the wall projection in which the window is located. This makes for small glass area. See next clause for clarification. The limiting distance to skewed projections or skewed side yards must be measured horizontally to the vertical plane of the projection (side yard bays, cantilevers, fireplace chases or pie shaped lots where the house wall is angled along the property line). The maximum glass area must comply with table Each opening in a skewed projection is taken as a percentage of the face of the projection in which the opening occurs. Each individual glazed opening (window) in the exposing building face cannot exceed 50% of the maximum area allowed in table UNLESS the building is sprinklered OR the limiting distance is more than 2 m. Each individual opening shall be separated 2m horizontally and vertically from other openings in the same wall if they are in the same fire compartment. The exceptions are: 1) Stacked windows that are in the same fire compartment which are on the same floor level 2) Windows can be installed less than 2 m apart if there is a floor to ceiling wall between the two windows that extends back into the house not less than 1.5 m. The wall must have a ½ gypsum board or an equivalent finish material. 3) The building is sprinklered. 4) The limiting distance to the property line is more than 2.m. The above conditions do not apply to the exposing building face of the house and a detached garage if the detached garage is on the same property and the detached garage serves the dwelling unit or a secondary suite within the dwelling unit. There shall be no openings in a wall that is less than 1.2 m from the property line Windows in walls that are 1.2m to 2.0 m away from the property line cannot exceed the maximum area of glazed openings in exterior walls as identified in table No individual window can be more than 50% of the total glass area as specified in the table. No roof overhangs are allowed if they are less than.45 metres from the property line. Roof overhangs that are less than 1.2 m from the property line must have no openings and be protected. The protection can consist of any one of the following materials: 1) 28 gauge mild or stainless steel. 2) 26 gauge unvented soffit and fascia. 3) 30 gauge galvanized steel. 4) 12.5mm gypsum board.

8 8 5) 11 mm plywood with all edges supported and caulked. 6) 12.5 mm osb or wafer board with all edges supported and caulked. 7) 11 mm lumber free of knots. All combustible projections into side yards with a limiting distance of less than 1.2m must be protected both inside and out. The interior of the wall(s) must be fire rated (45minute minimum) on both the face of the wall parallel to the property line and the side walls of the projection. Windows are not permissible in these walls. This basically eliminates side wall bay windows with a limiting distance of less than 1.2m. The inside face of a gable wall that is less than 1.2 m from the property line must also be fire rated. The exterior surface of these walls must consist of a non-combustible finish (19mm stucco, brick, concrete or asbestos tiles/sheets) or combustible finishes consisting of lumber, lumber shakes, plywood, osb, wafer board or vinyl siding installed over 1/2 exterior gypsum board. The underside of a projection that is less than 1.2 m from the property line AND more than.6m (2 0 ) above finished grade must be protected with any of the seven finishes noted above. ATTACHED GARAGES Walls and ceilings of attached garages SHALL have an interior finish consisting of: 1) Not less than 12.7mm (1/2 ) gypsum board (taped and mudded) ) Lath and plaster ) Any material that can be shown to remain in place and prevent the passage of flames for not less than 15 minutes. It must comply to CAN/ULC-S101- Fire endurance tests of building construction & materials (fire rating tests). It should be noted that OSB does not meet this standard. The walls and ceilings of attached garages must have thermal insulation complying with (R12 minimum in walls, R34 in roofs, R20 for bonus room floors above garages).