leave saw cuts in floor or fill them?

[Cult Hero]

Is it a personal decision, or are there any benefits to filling the cracks?

 

[bmwpower]

Pros to filling it in:
- No joint (or less of a joint) to roll your jack, etc. over
- Looks cleaner
- Stuff doesn't get lost in the crack

Cons to filling it in:
- Cost/time, although not much
- If you epoxy over what you fill it with, you might develop cracks over time

 

[swgray]

Pros to filling it in:
- No joint (or less of a joint) to roll your jack, etc. over
- Looks cleaner
- Stuff doesn't get lost in the crack

Plus a good filler will actually support the edge. It won't chip as much (and as large) as it will without filler, when things roll over it.

 

[JohnZ]

I left mine "as-cut", and when the floor was coated, the epoxy filled them to within 1/16"-1/8" below the floor surface. I considered filling them flush with the surface before coating the floor, but I figured they'd crack.

 

[carguy123]

On this subject, what is a cheap and easy way to score the concrete to get these cracks in the first place.

It is my understanding that this minimizes cracking, or rather gives the cracks a place to go instead of simply running who knows where across the floor.

 

[bmwpower]

On this subject, what is a cheap and easy way to score the concrete to get these cracks in the first place.

It is my understanding that this minimizes cracking, or rather gives the cracks a place to go instead of simply running who knows where across the floor.

Concrete saw about 1 day or so after the pour OR use a special tool used (edger?) for the purpose shortly after the pour.

Saw will leave squared edges. The tool will leave rounded edges.

 

[TNToy]

Cutting them into the floor with a wet saw is the best way to go. Leaves a narrower, squarer gap, so that T15 torx screw you drop while removing the headlamp assembly from a Camaro doesn't fall down in there and get lost.

 

[kartracer55]

On one side of the shop at work (building is an L shape) the cuts are 3/4 of an inch wide and about in inch deep. They are also located right under the engine when the car is setup on the lift, so they fill up with hardware and fluids. Pain in the ***... The best thing we have found is, if you decide to leave the cracks, fill them with oil-sorb.

Jim

 

[ersatzs2]

my concrete guy cut the grooves with a saw the day after the pour. Then said fill them in with caulk (they sell stuff that's supposed to be compatible w/concrete) to prevent the edges chipping. Now that it is epoxied the cracks are completely filled and even invisibile where the coating is thickest.

Interestingly, the saw of course cannot get closer than 6-8" from each end. The last 4" of each cut quickly developed a crack from the cut to the wall. So I guess there is some movement!

 

[toolman]

Interestingly, the saw of course cannot get closer than 6-8" from each end. The last 4" of each cut quickly developed a crack from the cut to the wall. So I guess there is some movement!

Mine did the same thing. Just goes to show you how well the saw cut controls and directs the crack as the cement shrinks when curing. I filled my saw cuts with filler out of a caulk gun. Before I filled them I check all the saw cuts and every inch of them had a hairline crack right down the center. They certainly did what they were supposed to do.

 

[elsensei]

When I cut mine, I used a small grinder with a 4" diamond blade to finish the cut to the wall. Worked perfectly!

 

[benchracer1]

Im thinking possibly of epoxying my floor then filling the sawcuts with a close color matched silicon sealer

 

[Hammerdown]

It does depend on what type of expansion joint you have. The saw cuts are less time and trouble to fill than trowelled grooves. Saw cuts can be filled with caulk- either acrylic/concrete or paint-able latex. I tend to stay away from the caulks that contain concrete, because they are more rigid and have a tendency to crack or come loose. The latex is easy to apply from a caulk gun and can be painted. If the crack is very large, fill it with Quikcrete foam backer rod before applying any caulk. Trowell joints typically need a more solid patching compond due to their size. Use a two part epoxy patching compond- (like bondo or similar product) to fill. Sand smooth before coating.

 

[Hammerdown]

Im thinking possibly of epoxying my floor then filling the sawcuts with a close color matched silicon sealer

Use a paint-able latex caulk- not silicone. Silicone products are not typically paint-able. DAP makes many colors of caulking, and probably one close enough to blend in.