How to Build a Ramp
How to Build a Ramp
There are many types of ramps for use in today’s world. There are concrete ramps, wooden ramps, and skateboard ramps to name but a few. In the end, however, the ramp is designed to move a person or item to a higher place from a lower place in a smooth fashion. There are many ways to accomplish the task of building a ramp, but there is one overriding geometric progression that gets the job done in all types of ramp. This progression is the 3-4-5 triangle.
The Layout
Ramps can take on any shape or form. In general, there is no real standard that says a ramp needs to have a particular slope or be made of a particular material. If a standard were to be used for one particular type of ramp it would be the Americans with Disabilities standard for accessibility. Every public building in the US must be friendly to handicapped people so a standard is required. In this instance a ramp must conform to the 1:20 rule. For each inch of rise, a run of 12 inches is required. Doing the math with this requirement indicates that a long distance is needed to reach doors or other access points. Layout and planning become important elements in constructing a ramp.
As the length of the ramp may dictate a 180 degree turn around, all measurements need to be right the first time to avoid digging new holes or re-nailing things. Measure several times and cut once. The 3-4-5 rule of geometry will keep your turn around square.
Footings and Posts
Once you have the general layout under control, check with your local building department. Every town is a bit different from the state code so check to see the correct procedure. As a general rule you will want to place footings with a 5 foot on center spacing. The turnaround platforms will need to have footings on all four corners. If you are in a region that has a frost line the footings should be dug to at least four inches below it.
At any home store buy a Sona Tube (basically a cone shaped cardboard tube) to be placed into the footing hole. It should rise to just 2-3 inches from the surface. Fill the tube with pre-mixed cement. For your posts make sure that the wood is soil-contact treated and rated. Now lay out the slope of the ramp onto the posts. Cross-joists should be placed at each of the posts.
Decking
The decking of the ramp also needs to be pressure-treated wood to prevent rot. Where in other decking type projects a space is left on the deck for water run through, this is less of a consideration as the wood should shrink a bit over time. To be safe, however, use your 1.5 inch galvanized nails as a spacer between deck boards. Railings need to be installed to code.