[lukevanoort]

You can get zip ties that can only hold twenty or so pounds, and ones that can hold over three hundred. Those don't look like the three hundred variety, so I would suggest switching them out for something a bit stronger. Anchors/screws are probably the best solution, and a hammer drill isn't even really that necessary to use them. We put up some pegboard in our shop a few weeks ago and did it just using a normal drill with a masonry bit. So, while a hammer drill helps, you may be able to get along without it. It's worth a try anyway.