I have a oval shaped low area (about 18" X 24" X 1/4" deep) that collects water if I wash a car inside or from rain/melting snow dripping from a car. Since I am working towards putting new coating on my garage floor I am considering filling this area. Originally I planned on leaving it alone since it's fairly close to the door and I can just squeegee the water out. But now is the time if I plan on fixing it. What can I use that can be feathered out at the edges and won't be noticeable when coated? I'm leaning towards a Polyurea coating and plan on using a primer. Thanks in advance for any advice.
Filling small "bird baths" like this can be problematic. Part of the problem is that the product has to be ground down to a feathered edge. Feathered edges can be weak. Also, self-leveling is more of a misnomer as they don't self-level like you would think. Most repair products that you can pour like a liquid are polymer-modified cements. They do not cure as strong when mixed to that state. Do not confuse self-leveling products with underlayments. These are not wear surfaces and are designed for indoor use only to be used under tile, wood, carpet and etc.
Since it's a coating that you want to apply, your best bet would be to fill that area with a 100% solids epoxy. You can mix a batch up, pour it out onto the floor near the depression and then pull it over using a squeegee that is wide enough to bridge the depression.
You would need to grind the area to prep it for the epoxy first and then grind the epoxy flush with the rest of the concrete after it has cured. The epoxy will take to a feathered edge much better than a polymer-modified repair patch.
Of course something to consider is that a repair such as that will most likely cost close to $100 for the epoxy. Also, a question to ask yourself is where will the water go that is now being displaced?
