Garage Floors in Eagan, MN

What a Garage Floor Replacement Involves

The old slab is broken out and removed through the overhead door opening, which is the reason this job takes a crew rather than one person with a hammer. Under it you almost always find the original builder's fill, and in a lot of Eagan houses that fill was placed fast during a boom and never properly compacted.

We dig out whatever is soft, bring in clean rock, and compact it in lifts. A vapor barrier goes down where it makes sense. The new slab is poured four to five inches thick with reinforcement, tied to the foundation wall with dowels so it cannot drop away independently, and pitched a quarter inch per foot toward the overhead door so meltwater leaves instead of sitting under your tires. The finish is a light broom or a steel trowel depending on whether you plan to coat it later.

Signs Your Garage Floor Needs Replacing

• A gap where the slab meets the foundation wall. The floor has settled away from the house, and that gap gets wider every year.
• Cracks wide enough to see through. Hairline shrinkage cracks are normal. A crack you can fit a pencil into means the base moved.
• A low spot that holds meltwater. Water pooling in February means salt sitting on the concrete for months.
• Surface flaking and pitting. This is salt damage, and it starts in the tire tracks where the brine drips.
• One section noticeably lower than another. Settlement under a heavy vehicle is the usual cause.
• Rust stains bleeding up from below. Reinforcement is corroding and expanding inside the slab.

Why Garage Floors Break Down Here

Salt gets carried straight in

This is the one that separates a garage floor from any other interior slab in Minnesota. Every winter drive coats your wheel wells and undercarriage in road brine. You park, the garage warms up a few degrees, and all of it melts onto the floor and sits there. The concrete stays wet and salty for months, which is exactly the condition that drives surface failure.

Freeze-thaw right inside the door

The first several feet inside an overhead door swing above and below freezing constantly through the winter while the back of the garage stays steadier. That is why the damage is almost always worst near the door and mild at the back wall.

Poorly compacted fill under the slab

Garage pads sit on fill brought in to bring the floor up to door height. If that fill was not compacted in layers, it keeps settling for twenty years under the weight of vehicles. This shows up as a floor that cracked in a roughly straight line across the middle.

Weight the slab was never sized for

A floor poured in 1984 for two sedans is now holding a three quarter ton pickup, a boat trailer, and a lift. Thickness and reinforcement that were adequate then are not adequate now.

What Affects the Cost of a Garage Floor

• Square footage. A two stall and a three stall are different pours, and a deep stall adds more than people expect.
• Demolition and haul off. The old slab comes out through one opening, so removal on a garage floor takes longer than on an open driveway of the same size.
• How much fill has to be replaced. If the existing base is soft, it comes out. This is the single biggest variable.
• Thickness and reinforcement. Five inches with rebar for heavy vehicles costs more than four with mesh.
• Floor drains or trench drains. Adding one is far cheaper while the floor is open.
• Apron work at the door. Often the slab and the apron outside the door have failed together, and doing both at once is cheaper than two trips.

Repair, Coat, or Replace?

Crack repair with a semi-rigid filler is worth doing on a floor that is otherwise flat and sound. It keeps water and salt out of the crack and stops the edges from chipping under tires.

Epoxy or polyaspartic coatings look excellent and clean up easily, but they are a surface treatment and nothing more. A coating over a cracked, settled, or scaling floor will telegraph every flaw and peel where the concrete underneath is already failing. Coat a good floor, not a bad one.

Replace when the slab has settled, when it has pulled away from the foundation wall, or when surface loss is widespread. Those are base problems and salt problems, and there is no topping that fixes either. The good news is that a garage floor is a contained, predictable pour, and unlike an outdoor slab, it is not at the mercy of the weather once the concrete is inside and the door is down.

Garage Floor Questions

Call (651) 427-1250 or send the form with your garage size and we will come look at what is under that floor.