Looks good speeduk. I had loads of spikes at first, but it made it too hard to collect all the loot after a big horde. So now i just have 2 layers of fully upgraded iron spikes then a layer of sacrificial wood spikes i can chop down to reach the loot.
BTW these iron bars are amazing, you can make a walkway around your perimeter that you can walk on and shoot through! At first we kept falling off the wall trying to hit the zombies

. They dont save you from boomers blowing themselves up though, unless you made the walls higher, mine are a bit low, but I like to be able to jump off the wall without breaking my legs.
campbellh24, are achievements enabled in A15?