Since it is made of cement I don't think you'll be able to prevent it from cracking. But it shouldn't crack unless it's dropped or set on an uneven surface and then stepped on. There are sealants made for concrete that will protect it from moisture and stains and you can find them at HD or Lowes......maybe even Michaels. I've used concrete sealant on birdbaths and DIY table water fountains and it works well. You should be able to find it in either matte or gloss/satin finish.