To all: Over the years (in our business) we have joked about what we might find underneath a concrete floor during the install of a subslab system when we core through the concrete floor. The guys have joked about everything that could be found under the slab. But on a more serious note during a system install the other day we did find something that we had not seen before. On a number of occasion we have found a standard 4 inch interior drain tile present when we core through the floor next to a foundation wall but during a system install the other day we found a 6 inch clay drain tile that was present in a home built in 1967. From what we could tell the drain tile was installed completely around the inside of the foundation for moisture management. But from the picture it looks like it has been dry since the day it was installed. Anyway….thought it was a interesting picture (took the picture with a camera phone….with it stuck down in the port hole). I personally have never seen a setup like this before so I thought I would share it. Jim MedleyRadon systems 4U LLC ********** RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ***********