Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Timber Ramp using 2 x 10s

Status
Not open for further replies.

snapjim

Industrial
May 30, 2004
1
Having just completed a garage i need to build a ramp to get upto it as it is 14" higher than the orginal drive due to a high water table,

for this ramp my plan is to lay 5 railroad sleepers (which i already have) at 4' spacing coming away from the garage and lay scaffold boards (2x10's) onto these. The slope is 15'long.

What i would like to know is will this safely support my wifes jeep weighing aroung 2500kg. what sort of deflection will i get.

Any help is much appriciated
James,
 
Replies continue below

Recommended for you

assume #2 SYP
Over stresses design in bending
Reduce span
 
Consider pouring a concrete aproach apron. Cost is probably similar. You could do it yourself. Maintenance is easier.
 
Agreed, the stabity is much better
 
You could purchase 2 by 12s, 14 or 16 foot long and rip them into wedges.

Drill them for 1/4" threaded rod and 'string' them together to create ramps. One plank will create two ramps.

Depending on your taste, you can create two ramps and go with that, or you could create several ramps and then deck them with two sheets of 3/4 plywood. You need to have each ramp broad enough to provide its own stability, and you need to space them closely, to avoid overstressing the decking.

You might use spacers between each wedge to broaden the ramps and thereby increase the ramp stability. Deck with plywood if you think the gaps would collect debris or damage tires.

Treated lumber is available as dimensional and plywood. Use the correct fasteners.

The concrete ramp isn't going to be as simple or as cheap as you might think. Some excavation would be needed. The concrete would need to be delivered to the location.
 
SnapJim,

The 2x10s will be on the verge of snapping, SnapJim. I calc 1.2 inches of deflection using E=1 mill psi and a 48" span (I would expect even more deflection because flat boards don't follow beam theory very well). With Fb' of 1000 psi, you can span about 10 inches with a flat 2x10 assuming 1375 lb (one wheel) @ midspan. Not much sense in that.

Plan C: Shorten the ramp since you're only climbing a foot, shorten the span to 2 ft and use 3x10 pressure treated members since its exposed. Quick calcs indicate this may work but you may still have foundation problems in wet weather and you'll have a nice hideout for rodents.

Plan D: Compact the ramp to grade minus 3" or 4" and place a concrete slab, preferably with WWF reinforcement. Properly done, it will last for the life of the garage.
 
"Architectural Graphics Standards" suggests 6 degrees "breakover angle" for ramps in and out of garages.
14 inch rise ~ 133 inch run. Your wife might get away with less run with a short, high vehicle like a jeep, but your Viper is going to rub its belly.

Snow and ice on our ~ 5 degree driveway are too much sometime. The particle board ramp to the shed is a traction problem for the lawnmower when
its wet. And the weather is beating it up.

Pressure treated wood may not rot, but as near as I can tell it splits, checks, and warps and jacks out the nails when subjected to wet/dry cycles just like regular wood .


 
Status
Not open for further replies.

Part and Inventory Search

Sponsor