Cracking exterior grout and rust on new cement pool

[Chefguy]

I appreciate you taking time to answer me back. You manage a great and informative site.
I’ve been trying to get in touch with the builder and he always answers me in a few minutes. We’ve actually became pretty good friends but since I’ve settled my balance on the build can’t get ahold of him.
I’m pretty much dismayed and I’m almond positive that there’s some bigger issues going on. We’ve noticed now over a dozen areas on the patio with rust seeping through. We keep it hosed off every day so it’s not stain from leaves, etc. when I spray it with the hose it’s rusty water. He wasn’t here when his crew was working most of the time. My only hope that since he’s been in the business for a number of years and is well known that’ll he’ll repair everything. As I’ve read on here and learned I realize that he over sold us on several things. Thanks again for the insight.

[PoolDoc]

Sorry for the experience you're having; I wish it was not so common!