Filling wide joint

[redpines]

I have a 1"- 1 1/4" gap between my garage floor slab and the adjacent driveway slab. Theres been the asphalt filler material in there for several years, but it's deteriorating and has never kept water from seeping between the slabs.

I'm ready to pull it out of there and replace it with whatever is best for this application. I'm assuming this means backer rod and some kind of caulk/filler on top.

What is the recommendation for filler? I want to do this right the first time. This is the full width of the driveway, 20 ft.

 

[ConCretin]

I'd remove the existing filler material, clean the joint, install backer rod to create the recommended joint depth relative to width and apply a primer and polyurethane caulk such as Sika 1A or Sonneborne NP1. Btw; backer rod does more than just fill the gap It creates a concave profile on the underside, which maximizes the adhesive surface area on the sides relative to a thinner more flexible area between.

 

[yanksoff]

I would probably use hydraulic cement.

 

[mike93lx]

I would listen to LLwillysfan on anything concrete related

 

[Shea]

I would listen to LLwillysfan on anything concrete related

You have two different materials that expand and contract at different rates. A flexible material, as LLwillysfan referenced, is what is needed to fill the gap.

 

[redpines]

I'd remove the existing filler material, clean the joint, install backer rod to create the recommended joint depth relative to width and apply a primer and polyurethane caulk such as Sika 1A or Sonneborne NP1. Btw; backer rod does more than just fill the gap It creates a concave profile on the underside, which maximizes the adhesive surface area on the sides relative to a thinner more flexible area between.

Thanks for this.

How difficult is it to get a good looking result with these products? Do I need to "tool" them to get them to lay right on a horizontal joint?

I had researched Sika's self leveling product, thinking that would be easier to get a decent looking result. I suspect what you are suggesting is a more durable solution. Is that a correct understanding of the trade off between these two products?

 

[ConCretin]

I had researched Sika's self leveling product, thinking that would be easier to get a decent looking result. I suspect what you are suggesting is a more durable solution. Is that a correct understanding of the trade off between these two products?

It can be a little tricky to get a nice finish with the standard gun grade sealants especially in wider joints where tooling is more difficult. The self leveling versions perform just as well but can be easier to install on flat surfaces. Just be sure to fill all the gaps so it doesn't disappear on you.