"If a foundation is porous or cracked, that is how gas gets in

“When gas leaks outside the wall can’t go into the air, they travel to the foundation and to every opening… if a foundation is porous or cracked, that is how it gets in”
How a Gas Leak Can Destroy a Building
So many homeowners DO HAVE one or more EXTERIOR cracks or other exterior openings, like these… https://www.youtube.com/watch?v=(http://kdvr.com/2017/09/brighton-family-narrowly-escapes-unusual-natural-gas-leak-into-basement/)

GAS line :45… water line 1:10 see any exterior openings…? Installing interior drain tile, drainage systems, pffffttt-pressure relief systems do NOT waterproof any of those. Insects, mice etc enter through these same type of exterior openings https://www.youtube.com/watch?v=b590J2E6he8)