This is an unfortunate problem which can sometimes be difficult to notice until it is too late, and the garage is flooded with water and snow melt. This can be a pain to clean out after every heavy rain and ignoring it can lead to mold in your garage and structural damage. Below we will discuss a few options for resolving this and consider the pros and cons of each.
Laying a new concrete floor
This is not a cheap option, and can be time consuming, but it is the best. Do not be tempted to lay regular concrete on top of the existing floor, as the new concrete will not bind to the original, and in a year or two the concrete will crack and break away, requiring further remediation work. Instead you should break up the old concrete floor and start again. Ideally, make the floor slope slightly from the back to the front so any water or snow melt brought into the garage will drain out.
Installing a drain
If repouring the concrete floor is too expensive or time consuming, another option is to install a drain at the back of the garage to collect and remove any water and snow melt. By placing the drain at the back of the garage, you will not have to worry about making it strong enough to withstand cars passing over it, and it is less likely to fill up with debris as it would if it was at the front of the garage. The main con is making sure the drain is tied into the drainage system to ensure the water is effectively removed away from the home.
Using a floor leveller
A high-performance cement-based floor leveller can be used if the slope is not too extreme. These tend to be quite expensive so better suited for smaller garages. You can scabble the concrete with a hammer and chisel to give a better bonding surface for the leveller. The main negative of this option is that it can only be used in certain situations.
Installing a garage door threshold seal
A garage door threshold seal can form a watertight barrier at the entrance to the garage and prevent wind-driven rain and snow melt from entering the garage. By preventing the water from entering the garage in the first place, you can avoid the issue of the sloping floor, and it is a very cost-effective option.
Whichever option you decide to pursue, we recommend doing plenty of research beforehand, and if unsure, contact a reputable contractor.