In last month's article we address the planning phase of building a ramp that took into account the wheelchair user's and care givers needs. This critical step, if over looked, can spell disaster when using the ramp. In saying this, what I am trying to convey is that if the ramp is constructed in such a way that it is too steep, the risk of loosing control of the wheelchair on the decent or not being able to push the wheelchair up on the accent. In both situations both the care giver and the wheelchair user are at risk for injury. I often tell my clients that a steep ramp is good for jumping over flaming cars but not for wheelchair use.

As a starting point, we do use the 12:1 ration that we spoke about last month, to determine the length of the ramp. This means that for every 1" of vertical rise, you will need 12" of ramp length. Therefore, a 24" rise would equate to a 24' long ramp. Please note that this does not take into account any type of grading issue that may present itself on the property in question, as many times the ground level slopes away from the home to account for run off. Although the vertical rise from the entrance of the home may read 24", the actual height maybe 27" at the point where the ramp starts because of this grading issue.

Now if the property does not avail itself for a straight 24' run of ramp then you will have to factor in a platform that will allow for a change in direction. We recommend a 4' x 4' section as a minimum space requirement. Please note that this platform should be level and is not included in the total length of the ramp.

For example, let's say that you need a 24' ramp but will need a right hand turn to accommodate the property and you place the platform right in the middle of the ramp. The ramp will run 12' to a 4' x 4' ramp then to another 12' section of ramp. This gives you a total length of 28', however the actual ramp length is still 24' long because the platform, being level, is not included in the sloping section of the ramp.

This generic 12:1 ratio does work for most people, however, if the person in the wheelchair is self propelling, that ramp should be longer and there should be a level section after every 30' of ramp length. Now if the person is using a power wheelchair, then check with the manufacturer for the maximum pitch that the chair can negotiate and build the ramp accordingly. Most power wheelchairs can ascend a ramp that is graded at a 12:2 pitch. This means that if you have 24" rise, a 12' ramp would be appropriate for a power wheelchair user.

We have found that under some circumstances, a 12:2 pitch can work for a person in a manual wheelchair that is being pushed by a strong/healthy individual, but this is as steep as we would every recommend. For this length to work, usually the wheelchair user leaves the home rather infrequently, say 1- 2x/month and is smaller in stature. Many times, if the rise is 24" a person can get by with a ramp that runs between 16' - 20', but again, it all depends on those 6 points that we brought up in last month's article.

If the person is leaving the home a daily basis, then we would never recommend cheating on the length of the ramp, especially if it is being used to cover a sizable vertical rise. (anything >30") Usually we lean more towards a longer length to ensure a safe and comfortable ride on the ramp.

The next point in designing your ramp will be selecting the material for it's construction and that will be the topic of next month's installment.