Kent County, DE Residential Code

Table R301.2(1), Climate and Geographic Design Criteria. Table R301.2(1), Climatic and Geographic Design Criteria, is filled in as follows:

Ground Snow Load	Wind Design				Seis-mic Design Cate-gory	Subject to Damage From
	Speed	Topo-graphic Effects	Special Wind Region	Wind-Borne Debris Zone		Weath-ering	Frost Line Depth	Ter-mite	Winter Design Temp	Ice Bar-rier Under-lay-ment Re-quired	Flood Haz-ards	Air Freez-ing Index	Mean Annual Temp
25 lbs./sq. ft.	115 mph	No	No	No	A	Severe	24"	Yes	18° F.	No	3-15-19787-2014	596	54° F.
MANUAL J DESIGN CRITERIA
Elevation		Latitude		Winter Heating		Sum-mer Cooling	Alti-tude Correc-tion Factor	Indoor Design Temperature		Design Temperature Cooling		Heating Temperature Difference
23 ft.		39°		18° F.		89° F.	1.0	72° F.		75° F.		56° F.
Cooling Temperature Difference		Wind Velocity Heating		Wind Velocity Cooling		Coin-cident Wet Bulb	Daily Range	Winter Humidity		Summer Humidity
14° F.		15 mph		7.5 mph		75	M	50%		50%

Section R310, Emergency Escape and Rescue Openings.

Section R310.2.5.1:

R310.2.5.1. Replacement window. At least one emergency escape and rescue opening complying with Section 310.2 is required in any sleeping room that is being added or gutted due to renovation to a structure.

(3)

Section R311, Means of Egress.

Section R311.7.5:

R311.7.5. Stair treads and risers. Stair treads and risers shall meet the requirements of this section. For the purposes of this section, all dimensions and dimensioned surfaces shall be exclusive of carpets, rugs or runners.
R311.7.5.1. Risers. The maximum riser height shall be 8 1/4 inches (209.6 mm). The riser shall be measured vertically between leading edges of the adjacent treads. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm). The riser height at landings with hinged doors shall be measured from the landing vertically to the top of the threshold (not the compression strip). The riser height at landings with sliding doors shall be measured from the landing vertically to the top of the highest projection of the door track. Risers shall be vertical or sloped from the underside of the nosing of the tread above at an angle not more than 30° (0.51 rad) from the vertical. Open risers are permitted provided that the opening between treads does not permit the passage of a 6-inch-diameter (102 mm) sphere.
Exceptions:
(1)	The opening between adjacent treads is not limited on spiral stairways.
(2)	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 (229 mm). 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 (9.5 mm).

(4)

Section R313, Automatic Fire Sprinklers Systems.

Sections R313.1 and R313.2:

R313.1. Townhouse automatic fire sprinkler systems. An automatic residential fire sprinkler system may be installed in townhouses.

R313.2. One- and two-family dwelling automatic fire sprinkler systems. An automatic residential fire sprinkler system may be installed in one- and two-family dwellings.

(5)

Section R315, Carbon Monoxide Alarms.

Section R315.2.1:

R315.2.1. New construction. For new construction, carbon monoxide alarms shall be provided in dwelling units.

(6)

Section R324 Solar Energy Systems.

Section R324.6:

R324.6. Roof access and pathways. Delete as written and add: Roof access, pathways and setback requirements shall be provided in accordance with Sections R324.6.1 and R324.6.2, through R324.6.2.1. Access and minimum spacing shall be required to provide emergency access to the roof, to provide pathways to specific areas of the roof, to provide for smoke ventilation opportunity areas, and to provide emergency egress from the roof.

R324.6.1. Pathways. Delete as written and add: A 36" pathway shall be provided on all edges, valleys and hips of roofs. Pathways on townhomes shall maintain at least 18" from the property line if the roof on either side of the property line shares the same plane. If the plane of the roof is different, a 36" pathway shall be provided on each side.

R324.6.2. Setback at ridge. Delete as written and replace with: A 36" clear setback is required on each side of the horizontal ridge.

R324.6.2.1. Alternative setback at ridge. Delete as written.

Chapter 4, Foundations.

Section R403, Footings.

R403.1.1, Minimum Size:

[1]

Delete: The minimum width, W, and thickness, T, for concrete footings shall be in accordance with Tables R403.1 (1) through R403.1(3) and Figure R4033.1(1) or R403.1.3, as applicable. The footing width shall be based on the load-bearing value of the soil in accordance with Table R401.4.1.

[2]

Replace with:

All continuous footings shall be a minimum of 8" depth by 16" width. Footings shall be sized to support the imposed loads. Footing projections, P, shall be not less than 2 inches (51 mm) and shall not exceed the thickness of the footing. Footing thickness and projection for fireplaces shall be in accordance with Section R1001.2. The size of footings supporting piers and columns shall be based on the tributary load and allowable soil pressure in accordance with Table R401.4.1. Footings for wood foundations shall be in accordance with details set forth in Section R403.2, and Figures R403.1 (2) and R403.1 (3). Footings for precast foundations shall be in accordance with the details set forth in Section R403.4, Table R403.4, and Figures R403.4 (1) and R403.4 (2).
Exceptions:
1.	Minimum footings for single-story decks shall be 3 times the widest nominally measured side of the post. Footings must also be sized to support the imposed loads; interior post locations support more weight than perimeter posts.
2.	Decks having vertical members spaced 6 feet (1,289 mm) on center or less may be placed on a 4 inch (101 mm) concrete pad, provided the vertical members are placed 12 inches (305 mm) inside the perimeter of the pad and are anchored on all corners with approved anchoring devices. Decks 20 feet (6,096 mm) or more in length shall have two additional anchors installed on each side mid-span.
3.	Residential accessory structures less than 300 square feet (27 square meters) in area, with the exception of a pole building and garage, shall be leveled and secured with tie-downs or equivalent manufactured home anchoring devices, one in each corner. Structures 20 feet (6,096 mm) or more in length shall have two additional anchors installed on each side mid-span. All lumber and wood siding is to be pressure-treated from grade to 8 inches (203 mm) above finished grade. Pressure-treated lumber shall meet the requirements set forth in Section R317.
4.	Prefabricated room enclosures are to be placed on an approved support system per the manufacturer's installation instruction.

Section R405, Foundation Drainage.

Section R405.1:

R405.1. Concrete or masonry foundations. Drains shall be provided around concrete or masonry foundations that retain earth and enclose crawl space/basements of habitable or usable spaces located below grade. Drainage tiles, gravel or crushed stone drains, perforated pipe or other approved systems or materials shall be installed at or below the top of the footing or below the bottom of the slab and shall discharge by gravity or mechanical means into an approved drainage system. Gravel or crushed stone drains shall extend not less than 1 foot (305 mm) above the top of the footing and be covered with an approved filter membrane material. The top of open joints of drain ties shall be protected with strips of building paper. Except where otherwise recommended by the drain manufacturer, perforated drains shall be surrounded with an approved filter membrane or the filter membrane shall cover the washed gravel or crushed rock covering the drain. Drainage tiles or perforated pipe shall be placed on not less than two inches (51 mm) of washed gravel or crushed rock not less than one sieve size larger than the tile joint opening or perforation and covered with not less than six inches (152 mm) of the same material.

Exception: A drainage system is not required where the foundation is installed on well-drained ground or sand-gravel mixture soils according to the Unified Soil Classification System, Group 1 soils, as detailed in Table R405.1

(b)

Section R405.2.3:

R405.2.3. Drainage systems. In other than Group 1 soils, a sump shall be provided to drain the porous layer and footings. The sump shall be not less than 24 inches (610 mm) in diameter or 20 inches square (0.0129 m²), shall extend not less than 24 inches (610 mm) below the bottom of the crawl space or basement floor and shall be capable of positive gravity or mechanical drainage to remove any accumulated water. The drainage system shall discharge into an approved sewer system or to daylight

Chapter 5, Floors.

Section R502, Wood Floor Framing. The following subsections are amended as follows:

R502.3. Allowable joist spans. Spans for floor joists shall be in accordance with Tables R502.3.1(1) and R502.3.1 (2). For other grades and species and for other loading conditions, refer to the AWC STJR.

R502.3.4. Deck floor joist spans. Deck floor joist spans shall be in accordance with the American Forest and Paper, Design for Acceptance #6, Prescriptive Residential Wood Deck Construction Guide.

R502.5. Allowable girder and header spans. The allowable spans of girders and headers fabricated of dimension lumber shall not exceed the values set forth in Tables R602.7 (1), and R602.7 (2) and R602.7 (3).

R502.5.1. Deck girder spans. Deck girder spans shall be in accordance with the American Forest and Paper, Design for Acceptance #6, Prescriptive Residential Wood Deck Construction Guide.

Chapter 6, Wall Construction.

Section R602, Wood Wall Framing.

Section R602.10:

R602.10. Wall bracing. Buildings shall be braced in accordance with this section or, when applicable, Section R602.12. Where a building, or portion thereof, does not comply with one or more of the bracing requirements in this section, those portions shall be designed and constructed in accordance with Section R301.1.

Exception: Porches with roofs and screen porches shall not be required to comply with the requirements of R602.10. Wall bracing, when constructed with approved translucent or transparent plastic not more than 0.125 inch (3.2 mm) in thickness.

Section R611, Pole Building Construction, through Section R614:

R611.1. Definitions. POST FRAME BUILDING: A structural building frame consisting of a wood truss or rafters connected to vertical timber columns or sidewall posts, which function as the principal gravity and load resisting elements of the building. A building used for motor vehicles is considered a garage and must meet the requirements in Section R309 as well as Section 614 of this code.

R612.1. Design loads. Plans are required to meet the minimum design loads noted in Table R301.2 (1). Uplift reaction forces involved are required to be provided.

R612.2. Truss design drawings. Truss design drawings are required at the time of plan submittal. The building plans should specify the permanent bracing for cords and webs to meet the bracing requirements shown on the truss design drawings.

R612.3. Size, grade, and species of wood members. All lumber shown on the submitted drawings should identify the size, grade and species or species group. Any engineered lumber should be identified by the product name, size and stress grade.

R612.4. Isolation of siding. Methods and materials to isolate steel siding from preservative treated lumber should be specified 26 and detailed on the submitted plans.

R612.5. Connection of truss carrier to bearing post. Submitted plans shall specify a bearing notch, properly designed bearing block, or other means for positive load transfer.

R612.6. Fastener schedule. Submitted plans are required to include a fastener schedule completely describing the fasteners and quantities required at each connection. Power-driven nails should specify the type, diameter and length.

R612.7. Roofing and siding diaphragms. Submitted plans shall include metal roof and wall panel thickness, fastener type and size, and the fastener pattern for roof and siding panels. If stitch screws are required to attach metal sheet-to-sheet, the plans should show the locations. Shingled roofs shall meet the requirements of Section R905.

R613.1. Footing depth. Footings for post frame structures shall extend a minimum of 40 inches (914 mm) below grade.

R613.2. Footing size. Footings for all post frame structures shall be sized to support the loads imposed. Minimum footing sizes for all post frame structures shall be 18 inches (457 mm) diameter and a minimum of 12 inches (203 mm) thick concrete under the support posts.

R613.3. Resistance to uplift. A lumber cleat shall be attached to the bottom of all vertical support posts to resist uplift. Exception: Other means to resist uplift may be used and should be noted on the submitted plans.

R614.1. Preservative treatment. All wood in contact with the ground shall be preservative-treated meeting the requirements of Section R319.

R614.2. Support posts. Support posts fabricated from multiple plies shall have the number of plies of lumber, lumber species, grade, and connection system between plies noted.

R614.3. Truss carrier spans. The allowable spans for truss carriers shall support the load of the proposed roof structure and floor system if present. Fabricated or dimensional lumber shall not exceed the values set forth in Tables R617.4 (1) through R617.4 (3). Spans exceeding the values set forth in Tables R617.4 (1) through R617.4 (3) shall be engineered.

Adopted appendixes. The following appendixes to the International Residential are adopted:

Appendix C, Exit Terminals of Mechanical Draft and Direct-Venting Systems, without changes or additions.