Sliding Gates on Sloping and Uneven Ground
It is OK if your driveway has a slope across it (camber) so long as the metal track the gate rolls on is reasonably straight.
If the bottom of the gate contacts the track while opening the motor may not have enough power to push the gate properly. You can pack the wheels out a little to raise the gate up enough to clear the track and then it should work fine.
If your driveway has slope across it (camber) of more than 20mm then the bottom rail of the gate should be raked to follow the contour of the driveway. This not only looks better it is necessary for fitting the "rack" to the bottom rail of the gate so the motor can work properly.
Raking the top rail depends on the fence line, if level then so should the top rail be, if stepped the top rail should match the lowest side of the fence line, if the fence is following the contour of the land then so should the top rail of the gate otherwise it won't look right.
Do NOT use Three Wheels on a sliding gate as this may de-rail the gate. Two wheels will always bear the load evenly. If the gate is very heavy then use two larger heavier duty wheels.
If the slope across the driveway is really steep or you have a really heavy gate you can counter balance the weight of the gate using Grant's Automation's eSlope mechanism that fits onto the guide post above the motor allowing a much smaller motor to be used and is generally a more economic and reliable solution than using a large motor.
Any slope up or down the driveway from the road has little effect on a sliding gate. The only thing necessary is that this slope is continued on to the concrete footing behind the fence so there is no sudden rises or twists in the gate track as this wouldn't be suitable for motor.
If a ground drops down from the edge of the driveway where the gate is to slide then the track may be elevated with a metal rail rather than using a big lump of concrete. This rail should be in line with the driveway so if the driveway slopes up a bit so should the rail. The rail should have support posts every 1m or so.
If the ground slopes up form the edge of the driveway where you want your gate to slide then an area will need to be excavated to allow space for the gate track. This area must be retained with walls that rise above the ground to prevent material blowing in and obstructing the gate track.
The gate track should be well drained and not have large volumes of water running up against it as this can wash silt and dirt up in the wheel bearings that may eventually cease up. The pad for the gate operator must be well above any ground water as this can cause problems for the operator.
Allowance for the weight of the Gate and Steepness of a Slope
Sliding gates going up hill will need a larger motor. Motors are rated for the weight of a gate on level ground and as soon as there is a small slope the motor then has to lift a portion of the gates weight so requires significantly more power and the cost of a much large motor can be high. A solution we have come up with for really heavy sliding gates up a steep slope or moderately heavy Telescopic gates on a moderate slope is to fit a weight balancing system that fits on the guide post and has a thin wire rope attached to the end of the gate. For more information on these please contact us.