A single top plate shall be tied at corners, intersecting walls, and in line splices in straight wall lines in accordance with table R602.3.2
7 3/4 inches is the maximum riser height in a stairway. 10 inches is the minimal allowable tread run.3\8 of an inch is the maximum tolerance permitted between the smallest and greatest riser height. And 3\8 of an inch is the maximum tolerance permitted between the smallest and greatest tread run.
Surface drainage shall be diverted to a storm sewer conveyance or other approved point of collection that does not create a hazard. Lots shall be graded so as to drain surface water away from foundation walls. The grade shall fall not be fewer than 6 inches within the first 10 feet.
Notches in solid lumber joists, rafters and beams shall not exceed one-sixth of the depth of the member,shall not be longer than one-third of the depth of the member and shall not be located in the middle one-third of the span. Notches at the ends of the member shall not exceed one-fourth the depth of the member. The tension side of members 4 inches or greater in nominal thickness shall not be notched except at the ends of the members.
Section 1. Question 1. * What is the purpose and scope of the International Residential Code?
Purpose of the IRC is to provide minimum requirements for one and two family dwellings and townhouses using prescriptive provisions. It is founded on broad based principles that make possible the use of new materials and new building designs.
- What is a dead load? A live load? Dead load is the weight of the materials of the structure such as walls, floors, roofing, cladding, etc. Live loads are the loads that the building experiences by the use and occupation of the structure.
Notches in solid lumber joists,shall not exceed one sixth of he depth of the member. shall not be longer than one third of the depth of the member and shall not be located in the middle one third of the span.The diameter of holes bored or cut into the members shall not exceed one third the depth of the member. Holes shall not be closer than 2 inches to the top or bottom of the member, or to any other hole located in the member.
here must illumination be located in relationship to interior stairways? Exterior stairways? Interior stairs shall have illumination of no less than 1 footcandle that illuminates the treads and landings with switches at top and bottom if more than 6 risers (if no remote or automatic controls are present). Exterior stairs should have illumination at the top of the stairs unless the stairs are accessing a basement level from grade in which the illumination shall be at the bottom.
- How many egress doors from a dwelling are required? Under what conditions is an additional egress door required? What is the minimum required size of an egress door? There shall be no less than 1 egress door for a dwelling unit. The width of the door shall be no less than 32 inches(when the door is open to 90 degrees) and no less than 78 inches tall. An egress door is required in a basement where there is no ramp or staircase that leads to an egress door or no other means of egress.
- Under what conditions is an unvented crawl space permitted? A crawlspace can be unvented if a class 1 vapor barrier is in place with joints overlapped by 6 inches and sealed at the laps. The vapor barrier must also go up the stem walls no less than 6 inches and be sealed. Also an approved air movement element must be in place such as a continuous operated mechanical exhaust at a rate equal to 1 cubic foot per minute per 50 sq ft with insulated walls.
The 2021 International Residential Code training has ask a question regarding Light-Frame Construction. To briefly explain… Light-frame Construction whose vertical and horizontal structural elements are primarily formed by a system of repetitive wood or cold-formed steel framing members.
Writing assignment #8: Maximum allowable ceiling joist span is determined by tables 802.5.1 (1) and (2). These tables are based on whether uninhabitable attics have limited storage or not which affects the amount of live load as determined in table R301.5. Roof rafter spans are determined by the ground snow load and whether the ceiling below is, or is not, attached to the rafters. In both ceiling and rafter span determinations dead load, wood type, spacing, and member size are included parameters.
Further limiting rafter span is the height location of the rafter ties above the rafter support walls. Increased height decreases allowable rafter span as detailed in table R802.4.1 (9). Collar ties are to be located in the upper 1/3 of the attic space and spaced not more than 4ft. on center
Writing Assignment #11
Q: * What is the maximum permitted length of a clothes dryer exhaust duct? How does the presence of one or more bends affect the allowable length?
A: As found in Section M1502.4.6.1; the maximum length of the exhaust duct shall be 35 feet. This maximum length does not include the transition duct.
The standards for installation of one or more bends can be found in Table M1502.4.6.1 DRYER EXHAUST DUCT FITTING EQUIVALENT LENGTH. These vary with the duct fitting type, mitered or smooth radius, and the the radius of the elbow.
Asphalt shingles shall be used only on roof slopes 2:12 or greater. 2:12 up to 4:12 double underlayment application is required in accordance with section R905.1.1 Fasteners for asphalt shingles shall be a length to penetrate through the roofing materials and not less than 3/4 inch into the roof sheathing.Where the roof sheathing is less than 3/4 inch thick, the fasteners shall penetrate through the sheathing. Asphalt shingles shall have the minimum number of fasteners required by the manufacturer’s approved installation instructions, but not less than four fasteners per strip shingle or two fasteners per individual shingle.
Writing assignment #9: A climate zone is a geographical region based on the criteria as specified in the IRC code which parallels the International Energy Conservation Code- Residential Provisions. These zones are illustrated in Figure N 11017 and detailed in Table N 1101.7. Thermal Climate Zones are divided 0 thru 8 using heating and cooling degree days for the location. Added to this is a categorization based on moisture, mean temperature, and rainy season. These are A (humid), B (dry), C(marine), and Tropical. Climate Zones are used to determine Maximum U factor assembly and minimum insulation R factors detailed in Table N 1102.1.2 and Table N1102.1.3. Maximum Energy Rated Index Table 1106.5 also uses Climate Zone determinate
- Can deck guard posts be notched? Deck posts that are 4in by 4 in shall not be notched for attachment purposes. All other attachments should be done in accordance to codes. R507.10.2
QUESTION: * **Where are smoke alarms required to be located? Do they need to be interconnected? How must they be powered? What must be done when alterations or repairs take place?
ANSWER: According to R314.3 smoke alarms are required in each sleeping room, outside of each separate sleeping area in the immediate vicinity of the bedrooms, on each additional story of the dwelling including basements, habitable attics, dwellings with split levels, horizontally from the door/opening of a bathroom that contains a bathtub/shower, and in the hallway & room open to the hallway.
Per 314.3, where more than one smoke alarm is required to be installed in an individual dwelling unit, the devices shall be interconnected.
According to R314.6, smoke alarms should receive their primary source of power from the building wiring, if that source is interrupted, a battery shall be used as a back up source.
In compliance to R314.2.2, where alterations, repairs, or additions requiring a permit occur, the individual dwelling unit shall be equipped with smoke alarms located as required for new dwellings.
QUESTION: * When are drains required around foundation walls? What drainage methods are acceptable?
ANSWER: According to R405, Drains are required around foundation walls when the foundation is not installed on well-drained ground or sand-gravel mixture soils. One acceptable method of drainage is to use "perforated pipe or other approved materials at or below the top of the footing or below the bottom of the slab & shall discharge by gravity or mechanical means into an approved drainage system. "
Writing Assignment #2
Q: Where is fireblocking required? What materials are acceptable for fire-blocking purposes?
A:
718.2 Fireblocking.
In combustible construction, fire blocking shall be installed to cut off concealed draft openings (both vertical and horizontal). It shall form an effective barrier between floors, between a top story, and a roof or attic space. Fireblockingshall be installed in the locations specified in Sections 718.2.2 through 718.2.7.
718.2.1Fireblocking materials.
Fireblockingshall consist of the following materials:
- 1.Two-inch (51 mm) nominal lumber.
- 2.Two thicknesses of 1-inch (25 mm) nominal lumber with broken lap joints.
- 3.One thickness of 0.719-inch (18.3 mm) wood structural panelswith joints backed by 0.719-inch (18.3 mm) wood structural panels.
- 4.One thickness of 0.75-inch (19.1 mm) particleboardwith joints backed by 0.75-inch (19 mm) particleboard.
- 5.One-half-inch (12.7 mm)gypsum board.
- 6.One-fourth-inch (6.4 mm) cement-based millboard.
- 7.Batts or blankets of mineral wool, mineral fiber or other approved materials installed in such a manner as to be securely retained in place.
- 8.Cellulose insulation tested in the form and manner intended for use to demonstrate its ability to remain in place and to retard the spread of fire and hot gases.
- 9,Mass timbercomplying with Section 2304.11.
- How is the maximum allowable spacing of wood studs determined? How is a double top plate to be installed? A single top plate?
Table R602.3(5) is used to help determine the answer to these questions. The table helps determine stud size, length and spacing, sheathing requirements.
R602.3.2 Explains the requirements for top plate installation, if it is a double or single plate.