Under the provisions of Sections 39-4109 and 39-4109A, Idaho Code, the codes enumerated in this section are hereby adopted and incorporated by reference into these rules. (4-6-23)T
TABLE R302.1(1) - EXTERIOR WALLS
EXTERIOR WALL ELEMENT | MINIMUM FIRE-RESISTANCE RATING | MINIMUM FIRE SEPARATION DISTANCE | |
Walls | Fire-resistance rated | 1 hour-tested in accordance with ASTM E 119, UL263, or Section 703.3 of the International Building Code with exposure from both sides | < 3 feet |
Not fire-resistance rated | 0 hours | > 3 feet | |
Projections | Fire-resistance rated | 1 hour on the underside, or heavy timber, or fire retardant-treated wooda,b | >2 feet to < 3 feet |
Not fire-resistance rated | 0 hours | > 3 feet | |
Openings in Walls | Not allowed | N/A | < 3 feet |
25% maximum of wall area | 0 hours | > 3 feet to < 5 feet | |
Unlimited | 0 hours | 5 feet | |
Penetrations | All | Comply with Section R302.4 | < 3 feet |
None required | > 3 feet |
For SI: 1 foot = 304.8 mm.
N/A = Not Applicable
a The fire-resistance rating shall be permitted to be reduced to zero (0) hours on the underside of the eave overhangif fireblocking is provided from the wall top plate to the underside of the roof sheathing.
The fire-resistance rating shall be permitted to be reduced to zero (0) hours on the underside of the rake overhang where gable vent openings are not installed. (4-6-23)T
TABLE R403.1
MINIMUM WIDTH OF CONCRETE, PRECAST, OR MASONRY FOOTINGS (inches)a
LOAD-BEARING VALUE OF SOIL (psf) | ||||
1,500 | 2,000 | 3,000 | > 4,000 | |
Conventional light-frame construction | ||||
1-Story | 12 | 12 | 12 | 12 |
2-Story | 15 | 12 | 12 | 12 |
3-Story | 23 | 17 | 12 | 12 |
4-inch brick veneer over light frame or 8-inch hollow concrete masonry | ||||
1-Story | 12 | 12 | 12 | 12 |
2-Story | 21 | 16 | 12 | 12 |
3-Story | 32 | 24 | 16 | 12 |
8-inch solid or fully grouted masonry | ||||
1-Story | 16 | 12 | 12 | 12 |
2-Story | 29 | 21 | 14 | 12 |
3-Story | 42 | 32 | 21 | 16 |
For SI: 1 inch = 25.4 mm, 1 pound per square foot = 0.0479 kPa.
aWhere minimum footing width is twelve (12) inches, use of a single wythe of solid or fully grouted twelve (12)-inch nominal concrete masonry units is permitted. (4-6-23)T
TABLE C404.5.1 PIPING VOLUME AND MAXIMUM PIPING LENGTHS | |||
NOMINAL PIPE SIZE (inches) | VOLUME (liquid ounces per foot length) | MAXIMUM PIPING LENGTH (feet) | |
Public lavatory faucets | Other fixtures and appliances | ||
1/4 | 0.33 | 31 | 50 |
5/16 | 0.5 | N/A - non-standard size | 50 |
3/8 | 0.75 | 17 | 50 |
1/2 | 1.5 | 10 | 43 |
5/8 | 2 | 7 | 32 |
3/4 | 3 | 5 | 21 |
7/8 | 4 | N/A - non-standard size | 16 |
1 | 5 | 3 | 13 |
1 1/4 | 8 | 2 | 8 |
1 1/2 | 11 | 1 | 6 |
2 or larger | 18 | 1 | 4 |
For SI: 1 inch = 25.4 mm; 1 foot = 304.8 mm; 1 liquid ounce = 0.030 L; 1 gallon = 128 ounces. (4-6-23)T
TABLE R402.1.2 INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa | ||||||||||
Climate Zone | Fenestration U- Factorb | Skylightb U-factor | Glazed Fenestration SHGCb, e | Ceiling R-Value | Wood Frame Wall R-Value | Mass Wall R-Value' | Floor R-Value | Basementc Wall R-Value | Slabd R-Value & Depth | Crawlspacec Wall R-Value |
5 | 0.32 | 0.55 | NR | 38 | 20 or 13+5h | 13/17 | 30g | 15/19 | 10, 2 ft | 15/19 |
6 | 0.30 | 0.55 | NR | 49 | 22 or 13+5h | 15/20 | 30g | 15/19 | 10, 4 ft | 15/19 |
(4-6-23)T
TABLE R402.1.4 EQUIVALENT U-FACTORSa | ||||||||
Climate Zone | Fenestration U-factor | Skylight U-factor | Ceiling U-factor | Frame Wall U-factor | Mass Wall U-factorb | Floor U-factor | Basement Wall U-factor | Crawlspace Wall U-factor |
5 | 0.32 | 0.55 | 0.030 | 0.060 | 0.082 | 0.033 | 0.050 | 0.055 |
6 | 0.30 | 0.55 | 0.026 | 0.057 | 0.060 | 0.033 | 0.050 | 0.055 |
(4-6-23)T
TABLE R402.6 LOG HOME PRESCRIPTIVE THERMAL ENVELOPE REQUIREMENTS BY COMPONENT For SI: 1 foot = 304.8 mm. | |||||||||
Climate Zone | Fenestration U-factora | Skylight U-factor | Glazed Fenestration SHGC | Ceiling R-value | Min. Average Log Size In Inches | Floor R-value | Basement Wall R-valued | Slab R-value & Depthb | Crawl Space Wall R-valued |
5, 6 - High efficiency equipment pathc | 0.32 | 0.60 | NR | 49 | 5 | 30 | 15/19 | 10, 4 ft. | 10/13 |
5 | 0.32 | 0.60 | NR | 49 | 8 | 30 | 10/13 | 10, 2 ft. | 10/13 |
6 | 0.30 | 0.60 | NR | 49 | 8 | 30 | 15/19 | 10, 4 ft. | 10/13 |
aThe fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration. bR-5 shall be added to the required slab edge R-values for heated slabs. c90% AFUE natural gas or propane, 84% AFUE oil, or 15 SEER heat pump heating equipment (zonal electric resistance heating equipment such as electric base board electric resistance heating equipment as the sole source for heating is considered compliant with the high efficiency equipment path). d"15/19" means R-15 continuous insulated sheathing on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. "15/19" shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulated sheathing on the interior or exterior of the home. "10/13" means R-10 continuous insulated sheathing on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall. |
(4-6-23)T
Table R406.4 - Maximum Energy Rating Index
Climate Zone | Energy Rating Indexa |
5 | 68 |
6 | 68 |
a Where on-site renewable energy is included for compliance using the ERI analysis of Section R406.4, the building shall meet the mandatory requirements of Section R406.2, and the building thermal envelope shall be greater than or equal to the levels of efficiency and SHGC in Table R402.1.2 or Table R402.1.4 of the 2015 International Energy Conservation Code. (4-6-23)T
Idaho Admin. Code r. 24.39.30.004