The crawlspace/unfinished basement in my home has a two foot step down into it. Not a major issue but it would be when I was trying to manhandle my 100 lb. lawn mower in and out. The solution, I decided, was to put in a ramp. To make life even easier I also put in a smaller ramp on the outside.
Step 1: The Problem
Level out the floor and build a ramp that will support at least 300 lbs (me, my lawn mower, and some leeway).
Step 2: The Solution Design
To make sure the structure was solid I planned to fasten it to the concrete wall of the house. The rails lying on the ground would be pressure treated timber and the rest of the rails and uprights would be 2" x 4" lumber. The top would be 3/4" board. All of the pieces would be screwed together using metal ties and self-tapping screws to ensure strength at each joint. Some of the timber would be new from the hardware store and some of it recycled timber from a temporary floor that was no longer used.
Step 3: Level the Floor
The builder had put in a loose river pebble base layer to wick away moisture. I added additional material to make it more or less level. Then I put down a layer of rough sand to go under each of the ground rails that would enable me to fine tune the leveling.
Step 4: Prepare to Build the Ramp
I calculated how much timber I would need, cut everything to size and laid all the pieces out in the way they would be fitted together. Then I labelled each piece using a series of letters and numbers so that it would be easy to reconstruct with each piece correctly placed.
Step 5: Construct the Ramp
When the three main floor rails were in place I fixed three corresponding batons to the concrete wall using masonry screws. This was to ensure that the ramp always remained fixed and solid. The upright batons were fixed to the floor rails and the bottom cross bracing pieces fitted and screwed in place using the metal ties. Next the top rails were placed and then each of the uprights was fitted and fastened into position. The cross bracing for the top rails was added next. That just left the top board. This is a 3/4" x 9' board. Unfortunately, it was just too long to fit in my minivan so I had the store cut off a small piece at one end and then cut the board in two so it fitted in the van. I reconstructed the board with the small piece placed in the middle as I think this provides greater overall strength. To finish this ramp off I added non slip treads at intervals along the ramp. This stuff (I think) is very expensive so I placed it fairly wide apart. The treads are very useful particularly if I step on the ramp with wet shoes which may otherwise slip on the plain wood.
Step 6: The Outside Ramp
The top of the step is only a foot or so from the ground and this ramp was constructed in a similar way to the one I have described already. However, this one was made entirely out of old off-cuts and pieces recycled from the floor I mentioned earlier. Neither was it made as exactingly as the first one. You will see from the photo that I was a lot less concerned with the quality of this ramp. To make the transition from going up to going down as smooth as possible I fitted a piano hinge near the top of this ramp with a small piece of board fastened to the other side of the hinge. This makes for an almost seamless transition from up to down in either direction. Finally, I painted the outside ramp with a dark green weatherproof paint to protect it from the elements.
Step 7: Conclusion
The ramps have been in place since for six or seven months now and are working well. It is certainly an easy job to get my lawn mower in and out without struggling. I hope this little instructable is of use to you in your ramp building.