Barrier Free/Ramp Building
How to Build a Wheelchair Ramp
Skill Level: Advanced
Ramps are typically built in order to improve home accessibility for people who can't use stairs or need a gentler, less stressful way to enter or leave their home. A successful home accessibility project requires careful planning in order to be certain that the ramp meets the home occupant's needs, complies with local building requirements, is safe and sturdy, and is safe for use in all types of weather.
Consider the following before you begin the design and construction of a wheelchair ramp. Questions such as:
Who's the primary user?
What type of assistive device does the person use (cane, crutches, walker, manual or electric wheelchair)
Will the person's abilities change?
What are the local zoning requirements?
These are just a few of the questions that must be addressed before you begin your project. The following information should guide you in this process.
There are critical elements that must be considered prior to hammering the first nail, such as the specific point of entry to your home, the available area for ramp creation, the slope of the ramp based on the height of the level that the wheelchair must get to and local building codes.
Home Entry: The choice of the door to place the ramp on will be influenced by several issues including, ease of access from the points within the house to the doorway, the width of the doorways and if a ramp can easily be accommodated to any existing features of the doorway, such as stairs, platforms or porches.
Space Limitations That Impact Ramp Design: Many aspects of the design of a ramp are limited by the space available and obstacles (such as trees, buildings and walkways) that affect where it can be located. By constructing a U-shaped ramp, more ramp distance can be accommodated in a smaller space.
Ramp Slope and Size: The angle of the ramp surfaces and the length or run of the ramp is a critical project consideration. The ramp slope will impact the layout requirements, the expense involved and the ramp's ultimate usefulness. Slope is the angle relationship of vertical height (rise) to the horizontal length or projection (run). It's usually expressed as a ratio of these two measurements, with the rise figure frequently set at a unit of one. For example, a slope of 1:12 means that as each dimensional unit (usually inches) of height changes, the other side projects (or runs out in length) 12 units (inches).
Although other slope ratios may be used for constructing your ramp, the (American with Disabilities Act) ADA-recommended and the most commonly used slope is 1:12. This means that if your porch height is 24 inches off the ground, you'll need a 24-foot ramp to safely accommodate wheelchair access. If you plan on deviating from this standard, you should check your local building codes to be certain you're in compliance.
The maximum rise for any given ramp segment should not exceed 30 inches. After rising 30 inches in elevation, a flat rest platform should be provided before the ramp continues. A flat landing must be at the top and bottom of all ramps, and landings should always be at least as wide as the ramp itself and a minimum of 60 inches in length. Ramps that are used for direction changes should be a minimum of 60 inches by 60 inches.
The minimum, inside clear width of the opening between the opposing handrails must be at least 36 inches to accommodate a wheelchair. This means the ramp must be built at least 42-inches wide to allow for the 1 ½-inch spacing between the handrail and any surface and the actual 1 ½-inch handrail.
Building Codes: Explicit code requirements may be imposed by your homeowner’s association (HOA), city county or local municipality. Check with your local building office to see if a permit is required before beginning your project.
Standard Practices: There are many standard design practices that are commonly applied to your project based on your geographic area. Also, although these aren't legal requirements for homeowners, the ADA Standards for Accessible Design establishes practices for commercial ramps that may be useful for you to review and may be applicable or expected for home construction.
Handrails and Spindles: If a ramp run has a rise greater than 6 inches or is longer than 72 inches, then it's recommended to have handrails on both sides of the ramp. For safety, handrails should be placed along both sides of the ramp segment. The inside handrail should be continuous on switchback or dogleg ramps. The top of the handrail should be mounted between 34 and 38 inches above ramp surfaces. The space between the handrail and the wall or any solid surface should be at least 1 ½ inches. For ramps over 30 inches from ground level, spindles should be used. And a curb or crutch stop should be placed along both sides of the ramp to prevent wheels from leaving the ramp.
Ramp Materials: The actual material used for the ramp surface can be selected based on personal preference but should be stable, firm and slip-resistant in all weather circumstances. Composite materials, such as ADA-compliant Trex Accents® are an excellent choice. These products meet the ADA’s guidelines for slip resistance even in wet weather and are low-maintenance. Those who depend on a wheelchair ramp to preserve an independent lifestyle often don't have the mobility or strength to strip and refinish the ramp on a regular basis. For this reason, easy-maintenance handrail materials, such as Trex Transcend®, should also be considered to provide years of comfortable use.
The ramp configuration and the materials you use will impact how you build the ramp. Talk to your local municipality to determine if a building permit, inspections and any other relevant information are needed to build a safe wheelchair ramp. The steps outlined below will guide you through the general process for building a wooden ramp for a private home. This information is of a general nature and shouldn't be assumed to be accurate for your specific project needs. Contact an architect or licensed contractor prior to starting this.
Step 1: Based on the planning process described above, select the ideal location for your ramp. You can use Google Earth to get an overhead view of your property and to precisely position your ramp plan around obstacles.
Step 2: Measure the height from the upper landing location (this can be a porch, a deck, etc.) to the ground level. This distance, and assuming a 1:12 slope, will provide you with the information needed to determine the total ramp length needed to safely construct the ramp and provide safe home access.
Step 3: Now that you know the total run distance, or ramp length needed, select a ramp configuration that will work for your house. If the finished height of your porch is 24 inches from ground level, you'll need 24 feet of ramp. This can be best accommodated by an L-shaped ramp with a landing or a U-shaped ramp with a landing. The specific configuration and ramp lengths are a function of what will best accommodate your home.
Step 4: Start at the upper landing by locating the landing platform along the desired edge of the house or deck.
Once you've selected the exact location of your landing, place a reference nail 1 ¾ inches in on both corners of your landing. This will be the attachment point of cord to layout your landing. Keep in mind that the minimum landing size is 60 inches long.
Locate batterboards approximately 7 feet perpendicular from the house edge where you placed your reference nails.
Use the three-four-five triangulation method to check for square. This can be done by cutting a piece of mason's cord approximately 2 feet longer than the proposed landing platform.
Tie one end of the cord to the reference nail marking the left edge of the platform, and attach the other end to the batterboard.
Now measure 3 feet along the house edge that the landing platform will attach to and mark that spot.
Measure 4 feet from the house along the cord, and mark the spot with tape.
From the 3-foot mark, adjust the cord in or out so that the distance from the 3-foot mark to the 4-foot mark is 5 feet.
When properly aligned, drive a nail into the batterboard and tie the cord to it.
Attach a line level to the cord, and adjust the string up or down as needed to level the cord.
You now have a level line squared to the house. Perform the same steps on the right edge of the landing platform.
Step 5: Assuming a 60-inch landing platform, measure 58 ¼ inches from the wall along the cords on the left and right edges of the platform and mark them.
Drive in batterboards 2 feet outside of the two existing layout lines.
Cut a piece of mason's cord, and tie it to the two new batterboards. The cord should intersect the marks you made for the proposed ramp width on each of the first two cords.
Adjust the batterboards so the last cord you tied just barely touches the tops of the left and right edge cords.
Step 6: You now have three squared and level lines. The corners where these lines meet and where the lines attach to the house represent the outside edges of the corner posts. Mark the ground with stakes or spray paint where you need to dig footings for the posts.
Step 7: Dig your footings so they reach below the frost line. Local building codes will give you the required depth, diameter and shape of your footings. Some codes may require the bottom of a footing be wider than the top or may require gravel at the bottom of the hole for drainage.
NOTE: Before you begin any excavation, you need to call check for underground utilities. The North America One Call Referral Service (1-888-258-0808 or just dial 811) connects you to a national directory of utility companies.
Step 8: At this point, you're ready to pour the concrete. We recommend using a tubular concrete form (Sonotube), or pour the concrete directly into the holes.
Step 9: Fill the holes with concrete and smooth the tops level.
Replace the mason's cords, and use a plumb bob to find the centers for each post.
Set J-bolts in the wet concrete.
Leave about ¾ of an inch of the threaded portion sticking up where the post centers will be. Allow the concrete to set.
Step 10: Once the concrete footings have hardened, secure the metal post hanger to the J-bolt with a nut and washer.
Stand the post in the post anchor.
Plumb the post with a 4-foot level.
Brace the post and fasten it to the post anchor using the appropriate fasteners.
Step 11: Using the determined slope and run, and following the steps above, either construct another landing platform and continue the ramp or place the posts at the end of the ramp. Check your measurements prior to setting your footings and posts to ensure proper installations.
Step 12: Using joist hangers and 16d nails, attach the rim joists and interior joists per the illustration below. Use cross braces every 4 feet for added stability. If the run of any single ramp exceeds 8 feet, additional support posts or larger dimensional wood may be needed.
Step 14: You should now install the railing. The corner posts will be used as structural support for the ramp surface as well as the railing post. The ADA requirements for railings detail the overall railing height, hand-hold specifications, spindle placement and other safety issues associated with railing construction. Although not required for residential construction, it's recommended that these guidelines be followed. Check your municipal building codes for specific local requirements and any necessary permits. If you're using composite railing, follow the manufacturer's recommend installation.
Railing sections should not exceed 8 feet. If the ramp section exceeds 8 feet, it's best to center the middle posts along the edges. An intermediary post should be attached to the outer joists using ½-inch-by-6-inch carriage bolts to insure stability.
Step 15: At the end of the ramp, a landing should be constructed either of the same materials as the ramp, or you may choose to use concrete. The landing platform size should be at least as wide as the ramp and a minimum of 60 feet long.