3619 COLBY AVE 2019-01-28 - Laserfiche WebLink

• gn P S., 51°6- S r..-,.:�. - . ..:. ___._ 43`//2015 t • • Client preferences When designing a ramp that is not financed by the client or homeowner, trade- offs must be made between functionality and cost. Some client preferences can be accommodated with little impact on cost; others cannot. The ramp designer must deal with these tradeoffs to meet the client's real needs while ensuring that an agency intending to provide home access does not end up footing the bill for a great party deck. Access limitations It may be appropriate, particularly when designing a long ramp, to include steps or other means for non-disabled people (such as mail carriers and delivery people)to reach the doorway without navigating the ramp. Some standard design practices have been developed which provide simplified, low cost construction to take place. These standards are the starting point of each design, and although variations can and sometimes must be made to these standards, adherence to them is desired. The Standards of Ramp Design include: • Construction with treated lumber • In general "medium"length lumber should be purchased for efficiency and stability(2x4 and 2x6 boards 16' or less and 4x4 posts 10' or less). The designer may choose longer boards for a particular design in order to optimize the design. • Purchase standard 514x 6" deck board to minimize waste: 4-42"from a 14' board and 2-60"from a 10' board. • Assemble with screws (no bolts or nails except for joist hangers) • Standard width 42" clearance between posts (allows 39" clearance between railings) • Use three 2x6" stringers (see 90° and 180° Landing Detail drawings for ramp framing) • Posts 4x4" and spacing not more than 8 feet (6'nominal) • Posts to rest on 12"X12" piece of treated 3/4" plywood for ground support • Assure lateral stability of posts (cross bracing at least one place in each direction as needed as shown in Figures 1 and 2) • Stringers are attached to the posts with 3.5" screws where possible. Also use a high shear strength screw such as Spax, Torx or lag screw, 1/4 inch by 4 inch, at sill to home and at least one at every load joint, typically 2x6's attached to 4x4s. • Use of joist hangers required on all free stringers (not attached to 4x4) and use of hanger nails 1 518" required, not screws. • Use 2x6 beams 49" long (48" minimum) or as required under stringers at every 4x4 post pair supporting the stringers unless the stringers are resting on or very close to the ground. One beam is used if the stringer continues beyond the post.. A beam is used on each side of the post if stringers join at the post. A center post is not needed if a beam is used unless two stringers are joined. • In places where a free standing post does not have a beam cross member, 18.75" 2x6 blocks should be place between the stringers close to the post to stabilize lateral movement of the post. • Tall landings or ramps should have diagonal bracing between the posts to stabilize the structure. • Use 5/4 x 6" decking boards on ramp surface and attach with 2.5" screws. (Shank on 2.5"extends through the deck board and only binds the stringer.) • An overhead clearance of 6'8" minimum is always required above all walking surfaces. • Highly recommend use of a hand rail with finger hold routed out of 2x6. Ready-made vertical hand rails may be purchased in only 8 ft length at lumber yards. Vertical hand rails routed from a raw 2x6 can be obtained with any desired length. (Prior design using a 5/4x6 and 2x4 handrails raised some concern with some building inspectors due to the long reach for a finger hold.) • Railing height 36" above decking (height of 34-38" is allowed) unless >30" above ground where 36" minimum is required) • Railing extension beyond the ramp ends varies by individual constraints and installation. Where there is no physical interference and the railings are used by the client, 12" extensions can be used.