Cracks in a new shotcrete pool
Hey All -
So the shotcrete went into our pool on Tuesday 5/29/2012. Within a few hours of them finishing, I noticed some hairline cracks in the shotcrete. For the most part they are hairline cracks, but every now and then they thicken to where you could stick a pencil tip in there. Our climate is 100+ degrees every day, so we have been watering the shotcrete down religiously every 2-3 hours between the hours of 7:30 AM and 6:00 PM during the day. However, these cracks were there from the start. I am a little concerned because it seems like it has gotten longer to now it is close to 9 feet in length, although it hasn't noticeably widened. All of the cracks are on one side of the pool, on the bottom, where it is transitioning from 5 feet in depth to 4 feet in depth to the side wall (so there is some curve).
I have talked with both the Pool Builder (who has not come to look at the cracks) and the Shotcrete guy (who did see the cracks when he came to take his sprinkler back), and both of them are saying these cracks happen and that they are 'shrinkage' cracks. Pool Builder says they happen all the time in the summer and he has never seen them cause damage on one of the pools he built. Neither one recommends doing anything special to treat them. Even though the Pool Builder hasn't seen the cracks and gave his opinion that they are shrinkage cracks, he did agree to send the shotcrete guy on Monday to drill out the crack and re-apply a shotcrete mixture. That is scheduled to happen. I just want to do the right thing for the pool and make sure I am getting good information from the people that are working on it. If this process of drilling into the shotcrete to repair the crack is going to cause more damage than good, then I'd like to cancel that before it happens. Then again, I don't want to find out later this crack was deep and there is a leak or for the crack to expand and cause the Pebble Sheen finish to crack later....