How to Lay Underlay

To lay tile, linoleum, laminate and some hardwoods, it is crucial that the subfloor be level and in the best condition possible. In some cases, it is cost prohibitive to put in a new subfloor, so adding a nice clean layer of underlayment is a better solution. Underlayment is a 1/4 inch thick wood pulp product that’s durable and cuts easily. It is available from most hardware stores, lumber yards or home improvement centers.

Things You'll Need

• Tape measure
• 4 by 8 underlayment boards
• Broom
• Mop
• Circular saw
• 2-inch screws
• Drill
• Leveling compound
• Trowel
• Medium grit sandpaper

Instructions

1. Measure the floor with a tape measure to get the square footage of the room. The industry standard sheets of underlayment are 4 by 8 inches. Determine the number of sheets needed to fit the space.

2. Sweep the base floor with a broom and remove any dried and caked on putty, nails or other raised substances on the floor that would keep the underlayment from laying flat. The purpose of the underlayment is to create a smooth even surface for the finished flooring.

3. Lay sheets of the underlayment out around the room. It’s often necessary to cut some sheets down with a circular saw so they better fit the shape of the room. Plan the layout of sheets to maximize the use of as many full sheets as possible. Use 2-inch screws and a drill to anchor the underlayment to the floor.

4. Push the head of the screw down into the underlayment slightly so there are no raised bumps in the floor. Place the screws 3/4-inch from the edge and at 3-inch intervals around the board perimeter.

5. Fill uneven seams with a leveling compound by applying with a trowel and smoothing to fill the gaps. Allow the compound to dry overnight for best results. Use medium grit sandpaper to get the leveling compound smooth over the seam.

Tips & Warnings

• Have an assistant there to help you lift and position boards.

• Use caution with power tools and wear eye protection whenever the saw is in operation.

References

• “Black & Decker--The Complete Photo Guide to Home Improvement: More Than 200 Value-adding Remodeling Projects”; Editors of Creative Publishing; 2009