Wooden ramps can be used for many different purposes. A wooden ramp in front of a shed makes it easy to get lawn equipment in and out of the shed. They can be built and placed in front of a porch to aid in allowing wheelchairs access to the house with ease. Recreationally, they are a fun addition to the yard for skates, skateboards and bicycles. Basic carpentry tools and some wood is all that is needed to build a wooden ramp.
Determine the length for the ramp based on the slope, or grade, by considering the requirements for use. If the ramp is to be used for a wheelchair, the steepest it can be for ease of use is 1:12. This means one inch of rise for every 12 inches horizontally. If the height of the ramp must be 15 inches, multiply 12 by 15 to determine the length of the ramp. Using this example, the ramp would need to be 180 inches, or 15 feet long. Common slope for storage sheds is 1:8. Use the same method above to calculate the length of the finished ramp.
Establish the width of the ramp by measuring the opening at the top of the ramp with a tape measure. If it will be a free-standing ramp for recreation, decide on a width for the ramp based on common construction material lengths to reduce cutting.
Construct the side rails from 2-inch-by-8-inch pressure treated lumber in lengths appropriate for the project. If the maximum length available is less than what is required for the finished ramp, splice the boards together to obtain the required length. Cut sections that are at least 4-feet long and place centred over the splice. Secure with a drill and screwdriver bit with at least five exterior wood screws in a square with one in the centre on each side of the splice.
Construct a rail for each side and one for each 16-inches of the width of the ramp.
Measure from the top of the opening where the top of the ramp will be positioned the distance of the thickness of the planned ramp decking. For example, if the decking will be made from 1-inch thick plywood, measure down one inch below the threshold and mark the location with a pencil.
Hold one of the rails on edge with the bottom corner on the mark made in the previous step. Align the edge of a level vertically with the top corner at the top of the ramp. Draw a line from the top corner of the rail straight down along the level. Align the edge of a level horizontally with the top corner at the base of the ramp and draw a line from the corner of the rail horizontally along the level. This gives you the slant required for the top and bottom of the rail.
Cut the rail along the lines with a circular saw.
Measure from the top corner of the rail down two inches and make a mark. Use a scrap piece of 2-inch-by-8-inch lumber as a template to notch the rail for the header board. Align the side of the scrap piece of wood with the cut of the top side of the rail with the top of the scrap on the 2-inch mark. Trace around the scrap. Cut out the notch with a circular saw.
Lay the cut rail on each and trace the cut areas. Cut out the same sections on each of the other rails.
Cut a header board from 2-inch-by-8-inch pressure treated lumber the same width as the opening at the top of the ramp. Attach the two side rails with exterior screws with the header board aligned in the notches. Position the remaining rails at no more then 16 inches on centre across the header board and secure with exterior screws.
Hold the header board, with the rails attached, in position against the structure with the top of the assembled ramp frame aligned on the mark made in Step 5 based on the thickness of the ramp decking. Attach with one screw, hold a level horizontally on the top of the assembled ramp frame, level the header board and attach with a screw on the opposite side. Screw securely with five screws in a square with one in the centre between each rail.
Space the bottoms of the ramp rails evenly apart. Use a square at the top of each rail to ensure that the rails are square to the header board.
Cut the chosen decking to size and attach to the rails with exterior screws spaced 4-inches apart along each rail.