38830 – Floor Drain: Combined Floor Drain and Internal Trap Seal 38850 – Floor Drain: 22" X 14" w/Heavy Duty Grate & Secondary Domed Strainer 38930 – Floor Drain: Packing House Type w/Bucket, Partition Trap & Cleanout. The 2021 International Residential Code (IRC) Section 309.1 stipulates that a garage floor must slope towards the garage door or a drain. There is no code on how much the slope should be. Between 1-2% is considered as the best practice and will ensure good drainage. On average, a standard garage floor drain kit will run anywhere from $50 – $200, with installation fees being between $100 – $300 depending on your contractor’s pricing and where they’re located. You may also need to purchase a garage floor grate, which can run anywhere from $10 – $75 depending on the size and style you choose. "/>Garage floor drains codes