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Cost to Install a Garage Floor Drain

Installing a garage floor drain requires marking and cutting a concrete slab, excavating a trench, and setting a drain assembly, P-trap, and drainage pipe on a consistent downward slope. The trench is backfilled with clean rock before new concrete is poured and finished around the drain cover. Homeowners often take this on to improve garage-floor drainage or as part of a garage upgrade.

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Common reasons homeowners do this job

  • Improving drainage across the garage floor
  • Adding a garage drain during a floor or garage upgrade
  • Creating a drainage connection to an existing drainage system
  • Creating a drainage route to a dry well
  • Locating a drain at the garage floor's lowest point

DIY or call a pro?

This is a hard project because it involves cutting concrete, excavating a sloped trench, and installing the drain assembly, P-trap, and piping correctly. Consider professional help if marking the trench, establishing the downward slope, or pouring and finishing the concrete patch feels unfamiliar. Wear safety goggles and a dust mask while cutting concrete, use hearing protection with power tools, and confirm that the area is clear of underground utility lines before excavating.

Frequently asked questions

Can I install a garage floor drain myself, or is it better to hire someone?
This can be a DIY project for someone comfortable using a concrete saw, breaking and removing concrete, excavating, and finishing a concrete patch. Hiring help is worth considering when the drain route, the consistent downward pipe slope, or the concrete work is outside your comfort level.
What makes the price of a garage floor drain installation go up?
The price can rise with the job's size and number of drain units, labor time, drainage materials, and haul-away of removed concrete or other old material. Small jobs may also be affected by a minimum or trip charge.
What should I check before choosing the drain location?
Identify the garage floor's lowest point first so water can drain properly. Also determine whether the drainage line will connect to an existing drainage system or a dry well before marking the trench path.
Why does the pipe slope matter for a garage floor drain?
The drain assembly, P-trap, and drainage piping need a consistent downward slope. A key mistake to avoid is proceeding with the trench or pipe installation before that slope has been established.

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