Take Measurements
You will need to measure the width of the opening to which you plan to connect the ramp, the distance to the ground where the ramp will be ending, and the available length over which you can extend your slope.
There are a few common sense measurements that will help you to draw up your ramp.
- The first one is 40″ wide walkway, which can be cut from a 10′ – 5/4×6″ treated lumber board. These are by far the most economical of commonly available decking materials, especially for a structure that is a discretionary purchase.
- The second measurement is 1:12 which is the max slope allowed by International Residential Code. This means that if your deck is 12 inches from the ground, you will need to have a 12′ long ramp to approach it. That is also motivation to make sure at least one end of your porch is close to grade level on new construction.
- The third is 36″ high, the common height of a guard rail. By code the guard rail must be between 34 and 38″ from the front edge of your treads or ramp surface. One little tip to remember is that you can rip a deck board to 2.5″ wide and use it for the top of your guard rail, which makes a nice cap that is easy to grasp.
- Additional measurements to remember are 2″x6″x10′ which is the typical size of a deck ramp joist. This is assuming that you will be building a 40 inch wide ramp with 3 joists to support it.
Okay, so now you are ready to draw up a material list.
Material List
Concrete post base blocks set 12″ below frost line or disturbed soil line
Ground Contact Treated 6×6 corner and ramp posts (4×4 are quite strong and are allowed by IRC, but not some townships)
Ground Contact Treated floor joists
Severe Weather Treated 5/4″x6″ floor boards
Severe Weather Treated 2″x4″ hand rails
Severe Weather Treated 5/4″x6″ deck board for rail cap
2″x6″ joist hangers (IRC R505.7)
4″ deck screws for bracing joints (I use Camo green or Grip Rite gold)
3″ deck screws for structural joints (I use Camo green or Grip Rite gold)
2 1/2″ deck screws for floor boards (I use Camo green or Grip Rite gold)
1/4″ x 2″ flat head Tapcons
Tool List
Spade
Wheelbarrow
Landscaping trailer (or another way to dispose of dirt)
Mason saw
Cordless drill
Circular saw
Sawzall with long wood cutting blades
Router with 1/4″ radius bit
Extension cord
Speed square
Tape measure
Carpenters pencil
Chalk line or carpenters string
Building
1.Start by drawing out your ramp and also a material list to get a price and confirm that there are funds for the project.
2.Once you have any needed permits(I don’t need any in Union Township if I stay under 30″ in height), you can begin your project.
3.Set temporary shims on the deck steps and build temporary supports to support the rim joist at the front of your landing. Remember that you need 1/4″ of drop for every foot of deck space.
4.Measure in from the inside of the existing handrailing and subtract the width of both posts and both side rim joists to get the length of your back rim joist. Confirm that the resulting frame will match the board spacing on the existing deck. Cut your back rim joist to length and lay it on the steps where it will be fastened.
5.Measure out from the deck board surface to where you would like the front of the landing to be. Subtract the amount of overhang (1″ to 1/2″)and also the thickness of one rim joist to get the measurements of your side rim joists. Cut them and place them on the shims and temporary supports that you have already placed there.
6.Measure the back rim joist and add the thickness of both side rim joists and both posts to get the length of the front rim joist. Cut it and lay it on the temporary supports in front of the side rim joists.
7.Screw the frame together. Use 3 screws per 2×6 joint. (Those screws can hold about 800 pounds apiece, so they are pretty strong.) The back rim joist should be forward far enough so that you can screw the side posts on from the inside of the frame.
8.Screw the deck step posts into place from the inside of the frame.
9.Dig down and set your post footer blocks. You might want to use a laser level or a plumb bob to mark their location.
10.Stand up your posts and screw them into place from the back side.
11.Square up the frame and add your post angle bracing. This adds stability and aesthetics to your landing.
12.Once the rim joists are in place, mark the center joist locations and install joist hangers. Roll the center floor joists.
13.Now pull a string from the edge of the landing to where the end of the ramp will rest on the ground. Use one of the footer blocks to hold it in place while you measure the angle and length for your ramp joists. For a long ramp, you will need to add a cross joist between the rim joists at every joint that is supported by deck posts.
14.Using a level or plumb bob, mark where the posts will land on the ground.
15.Dig and set your post footer blocks.
16.Screw a temporary piece of blocking under landing to rest the ramp ends on while erecting ramp. Set temporary support to hold cross joist while assembling ramp.
17.Cut and set deck rim joists. Cut and screw a reinforcement block on the inside of front rim joist to strengthen rim joist end connection.
18.Cut and install the deck boards. An alternate method is to leave each board as long as possible, and align the back edge, cutting the front edge straight once the boards are fastened to the frame.
19.If you are building on concrete, you will need to taper the first board with a electric planer and fasten it to the concrete with Tapcons so that there is no bump at the start of your ramp.
20.If you are connecting to a paver sidewalk, you will need to dig out an area for the deck ramp boards to rest on the footer blocks.
21. For paver sidewalk, replace the gravel, tamp it, cut the pavers to fit the end of your ramp, and install them.
22.Measure, mark, and cut the posts to the correct height for the guard rail.
23.Measure cut and attach the 2×4 rails between the deck posts. You can screw the 2×4 rails into place from the top and bottom of the rail for a clean appearance.
24.Taper the top of the posts to fit the rail cap.
25.Install your rail cap.
26.Clean up.
Congratulations! You have successfully built an access ramp for your deck!
Resources: AWC.org