How to Screen and Refinish Your School’s Hardwood Gym Floors

July 25, 2024

School gym floors see a lot of foot traffic everyday between student sporting events, assemblies, and other activities. High-traffic floors often get worn down, leaving them looking dingy and unprofessional.

With regular cleaning, prompt damage control, and proper maintenance, your school’s gym floor can remain in top-notch condition for many years. This is important because parents, students, and school staff take pride in their facility’s floors when they shine. You want to be “top of your class” and outshine the competition.

If your school’s gym floors show signs of wear and tear, are covered in scratches, or are losing their shine, it is time to screen and refinish them.

These processes can bring your floors back to life and make them shine again. Screening and refinishing a gym floor is the most efficient and cost-effective way of keeping the floor well-maintained.

In this article, we will discuss why it’s important to screen and refinish gym floors, and go over the steps to take to get the job done.

Understanding the Process: Floor Screening and Refinishing

What is Floor Screening?

Floor screening is a process where professional cleaning equipment is used to abrade the top layer of polyeruthane.

What is Refinishing?

Once the floor has been screened, it is time to refinish by adding two coats of polyurethane. The new polyurethane topcoat is bonded and secured to the floor, providing stability and durability.

Pro Tip: A screen and refinish removes only the top layer of polyurethane, and then a new top coat is applied. A strip and refinish removes all layers of polyurethane, exposing the bare wood of the floor.

Preparing for the Job

Before we go over how to screen and refinish floors, let’s talk about the tools and materials you will need.

Materials and Equipment Needed:

Materials:

Dust Mop
Floor Scraper
Sanding Screens (about 40 of each grit – 80, 100, 120, 150)
40” Garage Broom
Old Household Towels
Plastic Watering Can
T-Bar (24” is ideal)
Vacuum Bags
Synthetic Applicator
Personal Protective Equipment (PPE)

Equipment:

Orbital Sander
Auto Floor Scrubber

How to Screen Hardwood Floors

The first thing you need to do in the screening process is remove the top layer of finish with cleaning equipment, to prepare the floor for refinishing. Then follow these steps:

Step 1: Clear the Area
Step 2: Clean the Floor
Step 3: Scrape the Floor
Step 4: Choose the Right Grit
Step 5: Screen the Floor
Step 6: Scrub the Floor
Step 7: Tack the Floor
Step 8: Prepare for Refinishing
Step 9: Refinish the Floor
Step 10: Reapply Finish
Step 11: Let the Floor Air Dry

Step 1: Clear the Area

The first thing you need to do before screening your hard floor is to clear all objects like balls, nets, sporting equipment, and other objects off the floor.

Step 2: Clean the Floors

Once the floor has been cleared, use a dust mop to remove all the dirt. A smooth floor is necessary to screen it properly and ensure that no dust or other particles get stuck to the finish.

Step 3: Scrape the Floor

Use a floor scraper to scrape up all the gum, stickers, tape, and other hardened substances from the floor.

Be careful not to gouge the wood and make sure you get corners and edges.

Step 4: Choose the Right Grit

Before you can begin, you need to select the right grit sandpaper.

Most faciltities start with the 80-grit and then switch to each additional grit, in ascending order (100, 120, 150).

You always start with the most aggressive (80) and then increase to the finer grits (up to 150) so you will have the smoothest surface for applying the new finish.

Step 5: Screen the Floor

To achieve a smooth, even surface on your hardwood floor before waxing, you’ll need to screen the floor using an orbital sander. For this task, an excellent option is theSquare Scrub EBG-28V PIVOT with a HEPA DRY Vac kit installed to help minimize dust and debris.

Sanding Directions by Grit Size
When screening, the direction you move the sander is based on the grit size you’re using. The goal is to remove any glossy finish and create an even, uniform texture on the floor for proper wax adhesion.

80-grit and 120-grit Sanding:
Start in the southwest corner of the room or gym floor, and guide the sander diagonally toward the northeast corner. These coarser grits are ideal for leveling uneven areas, removing scratches, and stripping old finishes. Moving in this direction ensures thorough coverage and helps prevent missed spots.
100-grit and 150-grit Sanding:
For these finer grits, begin in the southeast corner and move diagonally toward the northwest. These grits are used to smooth out the surface after the initial coarser sanding. Going in the opposite direction from the coarser grit passes ensures that any remaining imperfections are leveled and that the floor has a consistent texture.

Visual Cue for Completion
As you work, keep an eye on the floor’s finish. Once the shiny or glossy top layer is completely gone, the screening process is finished. The floor should appear matte, indicating that the surface is ready for waxing. At this stage, any gloss left indicates spots that need further screening.

Step 6: Scrub the Floor

After screening the floor, use an auto floor scrubber with just water in it to wash over the floor to suck up as much fine dust as possible. The bigger the machine, the better, because you cover more area and get up more dust.

Go over the floor with the scrubber twice.

Step 7: Tack the Floor

Tacking is a process that removes dust and dirt from a floor to prepare it for a finish.

For this step, you will need a 40” garage broom and old household towels.

Get the towels slightly damp and wrap over the broom bristles, going over the entire floor twice (once in each direction).

Check far corners and get every bit of grit and debris.

Step 8: Prepare for Refinishing

Once your floor is completely clean, it’s ready for refinishing. Take a plastic watering can – yes, like the one for gardening – (approx. 2 gallon size) and a 24” t-bar. If you’re using an oil-based finish, choose a weighted bar. If using water-based finish, go with a non-weighted.

Take a round-shaped synthetic applicator and put it over the t-bar.

Step 9: Refinish the Floor

Pour polyurethane into the watering can, tip up, and pour a 2-3” bead onto the floor, going up the entire length of the gym, starting at the left side.

Use the t-bar and applicator to follow at an angle. Going in one direction, cover the floor up to the wall, curving so the finish comes off away from the wall.

Pro tip: When using polyurethane, especially oil-based polyurethane, make sure your space is well-ventilated and that you are wearing a respirator mask. This helps protect you from inhaling contaminants that are mixed into the air.

Step 10: Reapply Finish

Once the entire floor is covered with polyurethane, let it dry completely.

You’ll want to put two coats of floor finish down.

If you use a water-based finish, apply a second coat in 6-12 hours. For oil-based, apply again 18-24 hours later.

Check manufacturer instructions for how long this should take, and ensure that no one walks on the floor during the drying process.

Step 11: Let the Floor Air Dry

Once your floor has been refinished, it needs time to dry. The warmer the weather, the quicker the floor is to dry, whereas the cooler and more humid the weather, the longer it takes. Proper ventilation can help speed up the drying process.

In general, you should wait up to 12 hours before walking on the floors. They should be dry to the touch. About 36 hours after coating, the floors are safe for light foot traffic with shoes.

How Often Should Hardwood Floors be Screened and Waxed?

Most school gyms get screened and refinished with two coats every two years.

Final Thoughts

Well-maintained floors create a more professional appearance and make guests feel welcome when they walk through your facility. It also makes students and school staff feel proud of the place where they learn and work every day.

If you’re located in the United States, Puerto Rico, or the Caribbean, Imperial Dade has a team of experts who can help you keep your floors looking their best.

Contact us to speak to a member of our team who can guide you through the floor screening and refinishing process and recommend the best products to use. We stock a variety of janitorial cleaning equipment, floor finishes, and floor care products.