Question
I am buying a house with a backyard.  I want to put a driveway in the back around 20 by 20 ft sq and i want to do it with brick pavers.  However the the yard is backed up against an alley that is divided by a old fence that needs to be replaced.  I need to put a gate up in place of the fence that comes up flush with the edge of the alley.  The problem is that the alley isn't completely flat and I was hoping to put a fence with rollers so that i could slide it open.  I was thinking about building a 1ft by 20ft section of concrete so that the rollers or track could rest on.  Would it be easiest to build the cement slab for the track and put the fence up and then build the driveway after?  

The backyard is also lumpy and rocky with terrible soil.  I figure that I should level it out and add new soil so that I can put down sod after the driveway is done, so I was thinking about just leveling the whole yard first possibly...?  Anything that you might be able to recommend for prepping the ground so that I could put in some palm trees and bird of paradise plants would be appreciated, but my main concern is about how to prep for the driveway, and whether or not you think I should put the concrete slab and the rolling fence in first?

Thanks, Jim

Answer

Paver Detail Jim:
So if I understand this question; you are actually asking three things:
1. How do you prepare the sub-grade or yard for a concrete or brick paver driveway when you have bad soil and imperfect grades?
2. Is it wise to install a concrete beam for a sliding gate prior to installing a paver driveway?
3. What soil amendments and preparations are appropriate for palm trees and bird of paradise plants?

Well Jim, there are a lot of things to consider before grading and putting in a new driveway like are there substantial existing roots to trees considered important? Is there surface water run-off that would be trapped or impeded by a new driveway? Is the gradient of the driveway conducive to a sliding gate? Are there any required fence setbacks, etc.

Please note that my answer is given without knowledge of these things so you need to consider them yourself.

Working for Amenity Architects LLC, I designed and installed many paver driveways, brick driveways and concrete as well. Brick is generally the term used to describe real clay made masonry units. You may be installing concrete pavers. The difference is only the material the masonry unit is made of. Note that some bricks are not made or suited for use as pavers on the ground. Only high density and high fired clay pavers (bricks) should be used for ground contact. Check with your supplier or vendor to be certain you get the right kind of brick paver. However in any case the ground preparations are the same no matter what material the paver is made from. If storm water run-off flows across the area of the driveway you will want the surface to be flush with the adjacent grades. Therefore you must excavate the soil for the pavers and sub-base.
The sub-base consist of the materials and preparations that go into making the ground ready for the pavers. In almost all applications pavers require a layer of crushed aggregates. These can include gravel, granite dust (fines), M10, crush-n-run (crusher-run),etc. Then typically a thin layer (usually about an inch) of fine particulates such as construction sand. Now, depending on where you live you may need a thicker layer of aggregates for your paver driveway to account for frost heave or frost layer. And if you plan to park any heavy vehicles like RV's or trucks, etc you may want to include a layer of geosynthetic fabric (aka Geo-textile) between the crushed aggregates and the sand setting bed. This helps spread the load and decreases the chances of sunken spots in the pavers. There are lots of pictures of projects featuring pavers on my site at http://www.amenityarchitects.com and I discuss pavers in my blog at http://www.seanjmurphy.com as well.

Jim I am going to assume because you stated palms and bird of paradise that you live in a frost free climate. So I will then suggest you probably need about 3-4" of crushed aggregate to be laid down for your paver driveway. First excavate about 7-8" of soil where the driveway is planned. Then lay out the crushed aggregate. Then you level and compact the aggregate with a plate compactor which you can rent at local tool supply store. Then you can apply 1" thick sand setting bed. You screed this with a 2x4 and make sure it is level with your driveway gradient. Finally you set the brick pavers in place and tamp them lightly. When the pavers are all installed you pour sand on top and sweep it into any fine joints. Finally you may want to run the compactor over the pavers again. I would put down a piece of plywood so that you spread the force out over a large area and don't create depressions in any one area of pavers. You'll also need an edge restraint such as a concrete bond beam or metal paver edger.

As for your gate, if the gate is to be a slider or sliding gate the line of travel must be nearly level. It may be ok to slope only a couple inches across 10' of slide depending on the gate. So you need to check the grade on the side of the driveway which the gate would slide on. I dont see any real problem pouring the gate slab first as long as you are very careful to work your paver and paver sub-base with the elevation of the concrete in mind. However it would be easier just to wait till you do the driveway to be sure you match grade.

As for soil preparations for plants. It really depends on your soil. I can not give you a detailed answer except to say that Bird of Paradise and Palms are not very pickey and can grow in very poor sandy soil. And in fact, probably prefer very sandy laomy soil over anything with alot of organic materials and or clay. You might consider adding some slow release fertilizers and a little top soil in your plating beds by tilling it in the top 6" of soil or more.

Please check my new blog at http://www.seanjmurphy.com for more information on landscaping and my work or you can look at my company site http://www.amenityarchitects.com for ideas on your landscape solutions.

Amenity Architects is company that will soon be dedicated to providing content about outdoor amenities such as fire pits, BBQ's, arbors, pavers, patios, pools, etc.
I wish you the best of luck in your project.

sincerely,
Sean J Murphy, LA, ISA, LEED AP
www.SeanJMurphy.com
www.amenityarchitects.com