How to joint patio to house wall

[MattyP182]

Hi all,

I'd like to renew the patio joint where it butts up to house wall. It's variable in depth, maybe 4inches max. What is the best compound to use? What is there now appears to be concrete but maybe it's mortar like the rest of the patio joints but looks more grey to me. I was going to break this up a bit, remove then add mortar?

Thanks for the help

 

[Odds]

Use a polymer caulk. I don't think a backer rod would be needed in that gap.

 

[MattyP182]

Ok thanks, like an ms polymer? I've got Soudal Fix All and Sikaflex ebt. I've never used caulks across a span of 4 inches, just thin beads. If applied with a gun/tip how do you smooth it over? Putty knife? My experience is they're pretty tacky so imagine smoothing would be difficult.