Slab Leak Detection

Could someone please educate! I’ve been given different opinions on tests to detect slab leak(s) in my home. There is the sonar test, but unfortunately I believe our pipes are sleved and we may get a false reading. Is the isolation test and the hydrostatic test the same thing?

This is the approach that a soil engineer used to determine if there was moisture coming up through my house slab. He placed a known weight of desiccate material in several places on the slab and covered each with a glass pie dish. The pie dish was sealed against the slab using a removeable sealant.

After a couple of days, someone carefully collected the individual samples and weighed them. The difference in the weight was due to moisture and they correlated that data to the amount of moisture coming up through the slab per unit area.

A very complicate approach for the layman. You’re probably better off consulting with a soils engineer.

Dwight - Thanks for the reply. Sorry I wasn’t more specific about the nature of the problem. We have a plumbing leak in the slab on the hot water side. No visible signs of water inside or out or any increase in the water bill. Trying to determine the best method of detection without extreme $$ or damage to home.

How do you know you have a leak?

Paul - The hot water heater was cycling approx every 10 min. Had plumber replace controls and noticed that water wheel was spinning at main. No water running in house (toilet overflows ok, faucets off, no leaky valves, etc). Was able to determine it’s hot water side because when turn valve off on heater the wheel stops moving. Had the isolation test done this morning and determined leak in 3/4 in hot line running to master bath on other side of house. Guess we’ll incur cost to re-route.