Next was to install the sheathing or laths or whatever you want to call the horizontal boards that act as a framework to hold the thatch.  This was more difficult than it looks because it's not just as simple as getting the laser level out and making it level.  The rafters are not finished lumber, and they are supported by beams which are not finished lumber, and the beams are set on uprights which aren't finished lumber.  Get the picture?  Every error in each piece of wood is exaggerated by the next structural piece that's on top of it which isn't perfect either.  The main goal here is to line up the sheathing with where the welded wire is going to lay.  The sheathing is spaced 2' apart.  I purchased 6' welded wire fencing so there would only be 2 pieces cut per side of roof for a total of 8 pieces.  Welded wire fencing can be purchased from any decent hardware store, but you may find that 6' is a difficult size to find.  I could have used 4' (which is easy to find) and just used 3 pieces per side instead of 2.  Before cutting I strung the galvanized wire between 2 sturdy buildings and painted it (with a roller) a light tan color to get close to matching the color of the thatch.

The sheathing is plain old pressure treated pine 2x2s available at any lumber yard.  I attached them with regular hot dipped galvanized 12dx3" nails.   They can be difficult to work with because they're so thin and flimsy, but a bigger size would have looked out of place.  If there was a way for me to locate 2"-3" round posts, I would have used that, but you just can't find them because nobody makes a fence post that small.  Here you can see the painted welded wire fencing was rough cut and laid into place on the roof.  Then I came back and cut it to the exact size I wanted with a 4" grinder.  This was much faster and easier than trying to actually cut each wire with a set of diagonal cutters or bolt cutters.  The wire was held in place with hot dipped galvanized fencing staples.  A note here about all fastening hardware - because of the pressure treated woods, you must used either hot dipped galvanized or the specifically designed hardware for pressure treated which comes in a few colors.  The big hardware like lag bolts won't come in the specialty stuff, so you have to use hot dipped galvanized.  Regular plated and black bolts will quickly deteriorate inside the caustic chemicals used to pressure treat woods.

Unfortunately, I don't have any pics of the thatch actually getting installed, so all I can do is explain what I did.  The thatch comes in pre-woven 4'x4' sheets.  The front of the sheets is the pretty thatch, but the back is a woven diamond pattern where they sewed the palm leaves together.  Since only 1 side was decorative, I decided to put the first layer on the roof upside down so the decorative thatch could be viewed from inside. I started fastening the thatch with a staple gun, but found that didn't work very well.  Either my gun wasn't powerful enough, or the wood I was using was too dense.   I decided to use the same galvanized staples that I used to hold the fencing in place.  This worked well - at least for the first layer.  When I started installing the second layer (thatch side out), I wasn't happy with the coverage.  The thatch is very this and airy, even with these 2 layers.  So I decided to put down 2 layers right side out on top of the 1 layer facing in.  To do this I installed a 4'x4' panel every 2 feet which made a nice layering effect and still accomplished the double thickness.  Corners are difficult because after you bend the thatch around the corner, it doesn't lay in the correct direction, so you have to wing it.  I usually tried to overlap thatch from both sides to give really good corner coverage.  With there being so many layers of thatch overlapping, the standard fence staples wouldn't work any more.  I decided to use long stainless steel nails used to install cedar shingles, then I bent them around to hold the thatch squares in place.

After all the thatch is hung, you need a protective netting.  Plastic bird netting works fine and is pretty thin and nearly invisible.    The netting is then sewn in place using an upholstery needle and some thatch colored string.  Some people go for the more authentic look of fish netting, but this is quite a bit more expensive.

Here is the roof after a winter of being exposed to the elements of a PA winter.  The color has changed it's a little tattered.  This only gets worse.  WARNING:  although this has a really cool look to it, thatch has a *TERRIBLE* life span.  Don't expect to get more than 5 years out of it without doing major patching.  I've already done quite a bit of patching after 3 years.  It's best if you treat the thatch with a waterproofing wood treatment.  One other huge warning - this thatch cost me more than if I installed a cedar shingle roof.  If you know roofing, cedar shakes are VERY expensive.  If you add up the 3 layers of thatch, plus all the wood treatment, this was a very expensive roof.  On the 2 sides that you can't see, I've already given up and installed a fiberglass roofing materiel like you see on the pool shed.  This keeps all the water out and protects the thatch, but it looks terrible compared to the thatch.  That's why I only did it on the back 2 sides because nobody sees those.  From the inside you can't tell what I did because all you see is thatch.

One other option instead of the welded wire fencing is wood lattice to hold the thatch in place.  You need something to support the thatch because the it's too flimsy to hold itself flat.  It would sag in-between the sheathing.  Wood lattice looks pretty and can be stained a nice color or left natural, but for my design I wanted the look of "all thatch" from the inside.  I'm very happy with the results.

The corner joints were wrapped with a decorative manila natural fiber rope to make it look like the rope was holding everything together.

Here you can also see a close up of the look of the thatch against the wire fencing.