Concrete deck expansion joint repair

[brunoforestier]

See attached photos.

I stripped out my pool's old sealant a couple years ago and applied Vulkem 45 SSL into the expansion joints. I filled in the gaps with some foam backer rods before applying the Vulkem.

I expected the sealant to do a better job of adhering to the adjacent slabs, but in many spots around our deck, gaps are evident and I'm going to have to redo it.

Should I have applied a different sealant? Any recommendations here for how to do this right the next time?

 

[mknauss]

Let's see if @jimmythegreek can provide you some guidance.

 

[jimmythegreek]

I use sika brand. Theres a fine line with enough sealant and then too much wont level nicely. I actually tape off the sides amd caulk it then tool it amd remove tape. It's a pain amd time consuming. On even joints you can wing it freehand. That separation is the slabs moving, the sealant stayed put but got pulled apart by the weather amd temps

 

[mattw221]

The best material I've ever used is "Dow 790" It's pure silicone and I've seen it last 15+ years in expansion joints around pools. It will stay flexible indefinitely. You will have to tool it as it's not
self leveling but you'll never have to touch it again. Over time most of the other caulks will become hard and break down.