This is the “low” corner of my hawk-house foundation. It is “low” in that the interior ground level is lowest at this point to facilitate drainage. The actual foundation beams are fairly level with each other. The ground is highest where the door is and slopes evenly along the edges to this “low” corner where wash-water effluent that doesn’t soak into the ground can exit. The center of the hawk house floor is a small “mound” draining to the sides of the foundation. Hopefully the fabric that is in place under the hardware cloth will help to maintain the integrity of the floor shape and keep out vegetation while allowing dissolved mute matter to flow through into the crushed granite, sand and soil beneath.

The cedar beams shown are 4”x4”. I used cedar rather than treated lumber in order to avoid the chemicals in the treated lumber while getting some rot-resistance with the cedar. The cedar cost 4 times as much, but it's a small price to pay for the good of the hawk. An added bonus is the dimensional stability of the cedar. It won't warp or twist as much as the treated lumber. The 2”x4”s which are screwed into the inside of the 4x4 beams hold the fabric and hardware-cloth “pans” in place – a clamping-type of effect. I used small gravel on either side of the “low” end of the corner to facilitate drainage. I’ll use some hardware cloth to hold the gravel in place on the outside of this foundation corner and lay some sod about half-way up it.

The reason for the inletting of the 2x4s in the corners is to provide clearance for the galvanized, Simpson Strong-Ties screwed into the 4x4s on the inside corners. I'll caulk those gaps before I put up the siding.

You can see the ½”x30” anchor that I had to have at each inside corner. They are held in place with 2-1/2”x8” lag screws. This is required by our city code as we are in a hurricane zone 2. The anchors were "blue murder" to screw into place…

The material in the buckets is the rounded gravel that I used to fill in the interior of the hawk house. It is a wee bit larger than I wanted at ¼”-1”, but it was the only material that I could find locally which was washed and rounded. They had the much smaller pea gravel, but it had a lot of fines and sand in it which would wash down, form a concretion, and hamper drainage. I wasn’t about to undertake washing down a cubic yard by hand in a sieve or screen – too much work.

Tomorrow I start on the upright framing.

8/6/13: I've washed down the gravel with the accompanying hawk slices, dust, blown-in leaves, etc. numerous times over the past 2 years. The drainage works perfectly :-) I am well pleased that I took the extra time to contour the ground before putting down the membrane, hardware cloth and gravel.

9/22/15: As luck would have it my right knee went south on me, and I had to give up falconry. After 3 years the hawk house was dismantled and moved by someone who really wanted it. We took up the hardware cloth and weed-stop fabric. I was very pleased to see that the drainage for the effluent was contoured just as neatly as the day that I covered it all up with the pea gravel. During its time of use it had worked beyond my expectations :-) I highly recommend it to anyone who needs this type of drainage system.