Ramps can be faced with a variety of materials, including wood, brick,
and stone. Often the type and quality of the materials determines how compatible
a ramp design will be with a historic property. Unpainted
pressure-treated wood should not be used to construct ramps because it
usually appears temporary and is not visually compatible with most historic
properties.
Railings should be simple in design, distinguishable from other historic
features, and should extend one foot beyond the sloped area.
Ramp landings must be large enough for wheelchair users, usually at
least 5 feet by 5 feet (152.5 cm by 152.5 cm), and the top landing must
be at the level of the door threshold. It may be possible to reset steps
by creating a ramp to accommodate minor level changes and to meet the threshold
without significantly altering a property's historic character. If a building's
existing landing is not wide or deep enough to accommodate a ramp, it may
be necessary to modify the entry to create a wider landing. Long ramps,
such as switchbacks, require intermediate landings, and all ramps should
be detailed with an appropriate edge and railing for wheelchair users and
visually impaired individuals.
Temporary or portable ramps are usually constructed of light-weight
materials and, thus, are rarely safe or visually compatible with historic
properties. Moreover, portable ramps are often stored until needed and,
therefore, do not meet accessibility requirements for independent access.
Temporary and portable ramps, however, may be an acceptable interim
solution to improve accessibility until a permanent solution can be implemented.
Installing Wheelchair Lifts. Platform lifts and inclined stair
lifts, both of which accommodate only one person, can be used to overcome
changes of elevation ranging from three to 10 feet (.9 m-3 m) in height.
However, many States have restrictions on the use of wheelchair lifts,
so all applicable codes should be reviewed carefully before installing
one. Inclined stair lifts, which carry a wheelchair on a platform up a
flight of stairs, may be employed selectively. They tend to be visually
intrusive, although they are relatively reversible. Platform lifts can
be used when there is inadequate space for a ramp. However, such lifts
should be installed in unobtrusive locations and under cover to minimize
maintenance if at all possible. A similar, but more expensive
platform lift has a retracting railing that lowers into the ground, minimizing
the visual effect to historic properties. Mechanical lifts
have drawbacks at historic properties with high public visitation because
their capacity is limited, they sometimes cannot be operated independently,
and they require frequent maintenance.