TL;DR:
- How should I fill this V shaped, shallow control joint in my garage most effectively?
- Joint rough dimensions:
- 5/8 in. wide at bottom
- 1 in. wide at top
- 3/8 in. deep
- Do I need backer material or can I just caulk it?
- The joint has been painted over with an epoxy but it is an uneven surface
- Should I rough up the sides of the joint prior to applying?
- Will self-leveling sealant adhere to the roughly painted joint?
Details & Photos:
I need advice on how to caulk the control joints in my garage. I'd like to fill in the joints to make it easier to clean and make the floor a little smoother. That will help with my rolling hydraulic jack, etc.
I've done a bit of research so far and it seems like I need to get (something like) Sikaflex self leveling sealant for the control joints.
My primary issue is this: the control joints are not very deep. Do I need to use a backer rod when I caulk this or should I simply fill it the way it is? I have also heard of "silica sand" being suggested.
The joints appear to be about 5/8 in. wide at the bottom and 1 in. wide at the top. They are approximately 5/16 in. deep (maybe 3/8 in).
Additionally, the floor and joints have been epoxied and I am wondering if this will have an impact on the caulk's ability to adhere to the surface.
Here are some pictures:
Width of the joint from the top (perspective slightly skews measurement):
Width of the joint from the bottom:
Any pointers are greatly appreciated!
Update: Project Complete
Thanks for the help! Sorry I can't award more than one answer!
I finished caulking the floor almost a week ago and it turned out all right! I went a little overboard in some spots on the joints and should have used less sealant, but it will get the job done functionally. The sharpest looking areas have caulk just below the line of the joint.
Joints with tape around them after caulking:
My garage is rather small - roughly 19.5' deep x 16.5' wide. I ended up using about 3-1/4 tubes of the 29 oz. Sikaflex Grey self leveling sealant. The joint is mostly 3/8 in. deep but I noticed some rough spots in the joint where it was closer to 3/4 in. This wasn't widespread, so I didn't address it and thus far everything has held out just fine.
I also used some extra painter's tape on the outward facing end of the center control joint to create a dam for the caulk. This is the end of the joint closest to the garage door that doesn't abut a wall; it's just open to the outside.
The caulk spilled out of the painter's tape "dam" a little bit, but I cut the spilled caulk off the tape when it was partially cured about 9 hours later. When the caulk is a little green it's pretty easy to cut with a utility knife. I've left the dam in place and plan on removing it tonight or tomorrow as I wanted the caulk to cure all the way through and not spill out the bottom.
Finally pulled a car into the garage on Sunday, so about 3-1/2 days after I caulked it. The caulk does seem to attract tire marks, but that's all right. The garage floor is intended for use.