Expansion Cracks in floor

[Capt10]

Hey guys! New to the site and a have to say its a pretty nice forum. So when I moved into my house six years ago I coated my garage floor with the Rustoleum epoxy from Home Depot. I have a three car garage and live in Colorado, so I get to experience all the seasons. Now my floor is beginning to peel. I did not properly apply the concrete etch. I have opted to grind/sand the old chipping parts and resurface the whole floor with new epoxy. So now to my question, How can I can I fill in the expansion cracks to give my floor a more "finished, smooth" look? I have heard of backer rod but what is that exactly? Any help would be great.
Nate

 

[ConCretin]

Backer rod is probably not what you are looking for. It is a foam material placed in a straight faced joint to control the depth of caulking and create a convex bottom profile.

The epoxy floor experts will have more for you but I'd chase the cracks with the edge of a grinder to open them up a bit and fill with a compatible caulking material.

 

[LegacyIndustrial]

If your joints are over 1/2" deep you might want to use backer rod and then fill in over top. The backer rod will keep your filler on top where it belongs.

 

[munkey]

The backer rod at Lowe's/HD is usually in the weatherproofing section. It goes by names like "Caulk Saver", but it's just a long tube of foam that comes in miscellaneous diameters.

 

[pauls340]

Backer Rod is a cellulose based product which has a two-fold reason to exist. First it is to eliminate "three part adhesion" meaning, when a joint filler (caulk) is applied it sticks to the left and right sides of the concrete and you don't want it sticking to the third side or bottom of the concrete saw cut because when that slab moves it will tear apart the joint filler. Backer rod prevents that three part adhesion. Secondly, backer rod partially fills that joint so you don't put as much expensive joint filler in it. I like to use Self Leveling joint filler because i'm not that good at caulking. Good Luck

 

[Capt10]

Thanks guys. I guess I'll make a run to Lowes.

 

[ScaldedDog]

I like to use Self Leveling joint filler because i'm not that good at caulking. Good Luck

I do the same, usually with SikaFlex from HD. It's expensive stuff, but works well.

Mark

 

[Flooring For Garage]

Just don't fill the cracks with mortar

I witnessed that once... The homeowner filled all joints with brick mortar than epoxied over everything. I'm sure it looked great (for about a week).