1) Removed the tree.
2) Extended the 2' retaining wall around the back of the yard so that it is level with the existing retaining wall, back-filled the wall with about 12 inches of 3/4 angular limestone gravel in a landscape fabric envelope, and put a fence on top. BTW, the height of the retaining wall at the highest point was 20 inches so I didn't do a draintile - just gravel.
3) Installed 4 inch sewer pipe (white) for all of the gutter outlets to this area and daylighted them through the wall in the corner.
4) I put in a 12x12 basin + drain grate in this back corner. In fact, my gutter drainage pipe is all tied in to the basin. Not sure that it will actually be useful as a drain though.
5) I redid the entire sprinkler system from scratch in the area so the heads can be properly adjusted to the new level (time consuming holy cow!).

Now I am at the stage where I am bringing the back yard up to level with the retaining wall and re-setting the grading. The area will be topped with turfgrass (Bermuda). Since it is a blank slate, I want to get the soil and grading right for drainage and grass. In general I am trying to do it right since this area is effectively built up from scratch. Since it is a small area, cost is no object. I have at my disposal anything from local landscape vendors. Most people use living earth stuff here. I have been filling the area with Texas Black which is very fine, clean, clay fill dirt. This is going on top of the existing soil which is almost all clay and rock. I know that I can't put grass down on the clay fill dirt so I must leave room for topsoil. The existing Bermuda had very poor topsoil. As near as I can tell, they just laid sod on top of the clay fill dirt which I think is normal for new construction.

Few questions:

1) I have the Texas Black (clay) as primary fill dirt. How much room should I leave for Topsoil?
2) When I put the topsoil on top, should I mix it in with the clay to create a transition? If so how much transition and how much pure topsoil?
2a) Any particular topsoil I should use? I have access to Topsoil+Compost mix which is the plan so far.
3) Should I grade the clay layer first and then put topsoil on top or grade the final clay+topsol mix from above?
4) Should I seed or sod? Cost doesn't really matter but the sod I have seen so far it grown in clay which might not be so ideal to layer on top of what I am preparing?
4a) If seed, it is basically 1st of August. Too late to seed? Any particular seed to use?
5) Since my regrading will encompass existing Bermuda areas, is it ok to just cover it with the dirt mixture I am asking about above? Do I need to cut out the old grass?
6) From the base of the foundation to the most distant point in the corner of the retaining wall where the drain is (roughly 40 feet), the elevation change is about 10 inches. This is about 2% gradient. Do I grade 2% evenly the whole way or do I put in more gradient near the house and less through the lawn. The existing codes recommend 6 inches in the first 10 feet from foundation. Because this area doesn't see any runoff from the roof now, it should only handle the water from the lawn surface itself if that matters.
7) My basin + drain sits about 4 inches below the retaining wall in the most distant corner of the yard. Not sure that it is necessary now. Any tips on how to grade the lawn to incorporate it? Or should I pull it out (cover it)? Could I create some swales to direct the water to it?
8) In preparing my area to take soil or sod, anything else I should mix in? Local guy said use some Texas greensand.

Any other questions I should be asking?

Thanks in advance!

eltbee

http://i.imgur.com/IyMgG.jpg

There are several places in DFW that sell the stuff you are trying to get rid of. They just fix it, and you can make a trade buy removing about 15 yards of your Gumbo, and trade it in for their mix for a fee. Per cubic yard of soil the recipe is 9 cubic feet of screened compost, 40-lbs Lava Sand,30-lbs Green Sand, 10-lbs Dry Molasses, 10-lbs animal feed grade Corn Meal, and 2-lbs worm castings.

You want to at least have 4inches of good top soil. So at 30 x 40 you are talking 15 cubic yards or 2 dump trucks full.

2A. Just put down 1-inc, rake it in and then apply the last 3 inches.

4A Use Bermuda Sod. My farm up in Tioga has Tifway-II and TifSport. Another good choice is Tifway_I aka 419. TifSport is a high grade stuff and cost the same as the other two.

5A depends on what type it is, and what type you go back with. Most likely it is Tifway-I. If you do not bury it it will come back.

6A. Codes i work with DO NOT RECOMMEND, they say SHALL BE A MINIMUM.

I'm having a hard time getting recommendations for sod vendors in Collin Co area. There seems to be only one. If you have a few I would be grateful.

That's right. Shall be a minimum is the wording used. Here is the snippet from a recent inspector's report:

Grading specifications are spelled out clearly in International Residential Code (IRC) R401.3,
"...Lots shall be graded so as to drain surface water away from foundation walls. The grade away from foundation walls shall fall a minimum of 6 inches within the first 10 feet... NOTE: The municipality�s plat drainage requirements can exceed those set forth by the IRC, i.e. require more than a 6" drop in elevation in the first 10� out from the perimeter of the foundation, but cannot be less stringent."

In code talk that is not a recommendation, it is a firm command, and failure to comply means you do not get a CO until you comply. Not only can the city keep you from living there, your insurance writer and bank can default you if they wish and take over ownership. Not trying to scare you, just stating the the code and facts. A lot like the bible when you read Thy Shall Not...

As for sod vendors try Denton County just to the west like Tri-Tex Sod Farm. For small projects like your one of the Nurseries should be able to supply you. Better yet from a money POV if you can get a PU Truck with a trailer go to a sod farm and pick up 3 pallets.

You have waaaaaaaaaaayyyy too much shade for bermuda. Tall fences and tall buildings surrounding a small area means you cannot grow bermuda successfully. You might have too much shade for any grass. Did you have a good looking lawn back there before embarking on the improvement plan? or was this project an attempt to make things better based on an assumption that poor drainage and soil was the issue?

Was the fence always that high?

The goal of the project was to raise the area and remove the tree. Basically we are doubling the size of our backyard in terms of usable (for kids) space. Other goal is to not create a drainage problem. Before it was excellent drainage but obviously by raising it, we must be mindful not to create a problem. For instance, I have put in drain pipe for all of the gutter feeds to that area and daylighted that directly out the wall. Before it was on the plane of the yard. Not ideal green thinking wise but it's done. Now that area only takes on water from the plane of the yard surface itself. I do have a drainage question related to grading which I'll post on the landscape forum.

Is there another grass that I should be using back there? It's not out of the question for me to have something completely different since the entire area save for about 5 feet, is surrounded by hardscapes (driveway, wall, patio, house). I'm open to any suggestion.

This weekend I added 1.5 yards of topsoil+compost and realized that I need more base fill to get the grading right. It's like a bottomless pit. My yard keeps sucking up the dirt. Where does it go? :) I will have to work in more base clay fill then add a final layer of topsoil before laying the sod. I invested in 36 inch landscape rake. Wish I had done it sooner. Also, all the while that I have been putting in dirt, I have been using a 10 inch tamp to pack it in. Should I back off on using the tamp for the final layer of top soil?

Picture is 5 days in to sodding after final clean up of area from project junk and setting the elevation of the sprinkler heads.

Follow-up question: I am short a few pieces of sod in a couple of areas not shown. How important is it for me to get 419 sod from the same place as opposed to another vendor than is close by? Tri-tex is a bit of a haul for a few pieces.

Thanks again all for the help with this project.

The estimates I got to do this work ranged from $3-5K. I did it for about $1K in materials. What I didn't plan on was the amount of my time that was required to pull it off. Definitely would have been worth it to pay someone else given the cost of my time. Final tally on fill materials was 10 yards of clay and 7 yards of topsoil all done by hand.

Thank you for your support. As long as it is certified 419 does not make much difference as it will acclimate to your area in a year.

Keep it watered, start mowing now, and feed it in 3 weeks.