Wood – How to stabilize a wooden lawn mower ramp over stairs

basementcircular-sawstairswood

I'd like to build a ramp for a lawn mower that is in the basement. The only way out is a set of stairs with a very little space to turn to them (that's why the ramp doesn't extend all the way to the ground). It'd be temporary placed over the stairs only when needed.

The steps are 13cm deep 25cm long each. This yields a 27 degrees steepness. 2 pieces of ramp will be made, 112x12cm each, have not yet decided on the thickness. It's either some 2cm thick solid wood or leftover laminated flooring pieces. At some point I wish to connect the two, to always be at the specific distance from each other.

With that said my current plan and biggest problem is how to stabilize the ramps so that they don't slide down (or up, when I drag the mower up). It's hard to cut 27 (63) degrees angle lengthwise with my circular saw, although I could do shallow depth large triangle pieces. These would be "cleats" or "studs" to grab on to the irregular old concrete steps somehow.

My question is which is bettter:

  • Purple triangle (or larger): shallow depth like 2cm
  • Blue triangle, small: cut at a length that is 12cm
  • Green bar, just a piece of regular lath, 12cm deep, fairly large
  • Other?

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My current plan is:
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It has 12.5×6.5×2.8 triangle pieces, 32 of them. Groups of 4 screwed together, forming a 11.2cm deep triangle stick to go on each step, on both sides.

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I'll cut it up like this. It's a 80x25x2.8 piece of wood and will have some leftovers to stabilize (perhaps a vertical piece).

Best Answer

If I saw someone building this ramp my first thought would be to add a block as shown in the picture. To me it just looks like an accident waiting to happen.

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Also consider starting from ground/floor level, as shown in this picture. enter image description here