Have a hard budget so builder included chemical injection under pool/spa only but not the travertine paver decking to save me cost. Pool builder said because my decking is not poured concrete and is instead travertine paver -they don't recommend. Chemical injection absolutely recommended by all pool builders because of north dallas fort worth soil. I absolutely agree it is worth it for pool/spa . But are they right that the chemical injection is not worth it for travertine paver decking??