pool tiles

Hi
we have installed coppers around a pool
instead of grout in the gaps between some of the tiles
they have put silicon they recon it is so it can flex
Is this correct as I have not seen this before

Thank you

ger,
Yes, sort of. Your copers will expand and contract at a slightly different rate than the concrete pool shell as the daytime temperatures change. The expansion joint will allow for this. Also, over a long time the copers may expand/grow slightly. Instead of popping off the pool they will expand into the silicon gap. My pool coping installers used clear silicon & over time with dust and dirt this matched the standard cement coloured grout. Pity they didn't use a commercial adhesive. I've had them back three times now under warranty to re-adhere the copers.