Installing Laminate Flooring on a Closed Staircase
A staircase that is closed at both ends will be the easiest step installation, but as with all installations, there are some fundamental steps that are critical to success.
It is important that the juncture of the step and riser is straight, and that the ends of each are square. Cutting the factory tongue from the end of a laminate plank ½-inch shorter than the shortest step and riser combination will provide a template that serves as a straightedge with square ends (Photo 1). Using the factory-grooved side of the plank as a straight edge, evaluate the juncture of the step and riser, both horizontally (Photo 2) and vertically (Photo 3).
At the same time, slide the straightedge/template to the left and right to check the ends of the steps and risers for square (Photo 4). Any step and riser combination revealing unacceptable deviation will have to be custom fit.
Once the evaluation is complete, consider your approach to the installation. In this case, the focus is on a conventional flush mount stair nosing that generally works best by starting at the bottom of the staircase and working up.
Most staircases in today's homes are pre-fabricated, then delivered to the home for installation. Therefore, removal of the existing bullnose is essential before attempting the installation. Cut the bullnose flush, using a power circular saw or jig saw, and finish the cuts with a hand saw at the stringer. BE CAREFUL! The finished stringers must not be marred during the removal of the bullnose. You can use a manila folder, cut to the contour of the step, riser and bullnose, to protect the finished wood (Photo 5).
The stringers in pre-fab staircases are mortised to accept the ends of the steps and risers. The removal of the bullnose will leave a small piece intact on the end of the step, filling the voids on the stringers. This may become an important later, as a fill piece to be painted or stained if the finished step does not cover the void (Photo 6).
After removing the existing bullnose, start at the bottom riser and cut a plank 1/8-inch shorter than the overall length of the riser. The height should be 1/16-inch shorter than the overall height of the riser (Photo 7). Place the factory-grooved side down and cut the tongue off the top. If required, you may scribe-fit the bottom of the riser before cutting the width of the plank to finished height.
Using a disposable adhesive-spreader nozzle, a caulk gun and a quality construction adhesive, apply uniform beads of adhesive down the length of the plank approximately 3/32-inch to 1/8-inch from the edge (Photo 8). Position the riser, press, then move the riser up and down approximately ¼-inch. Cut down the conventional flush mount bullnose molding 1/8-inch in length, place it in position on the step, dry, then measure the distance from the riser back to the grooved edge of the molding for the overall width of the plank. Subtract 1/8-inch from the length and width of the plank and cut (leaving the tongue).
Some laminates may require the full width of one plank and a portion of another to cover the step (leaving the tongue on the fill piece). The deductions allow approximately 1/16-inch on each end of the step and riser and 1/8-inch at the back of the step after installation. The spacing makes positioning easier, allows minimum expansion, and reduces the risk of a tight fit that would hinder uniform contact of the laminate with the adhesive and the step or riser surface. A tight, net fit may cause a popping sound after slight expansion when stepped on, as the laminate touches the adhesive.
After installation, caulk the expansion gaps on the ends of the steps and risers with clear or colored siliconized caulk (Photo 9). The gap in the back will be covered by the riser. Slip tongues usually make great spacers for the 1/8-inch gap at the back of the step (Photo 10). Again, apply the construction adhesive on the back of the step and the length of the plank, then position. Moving the step out ¼-inch and back again will flatten the ridges, create uniform contact and push the excess air to the ends of the adhesive beads.
Using the manufacturer's laminate adhesive and their adhesive application procedure, glue the joint, apply construction adhesive on the back of the conventional flush mount stair nosing and position to a net fit at the seam (Photo 11). You may pre-drill and secure the nosing after positioning with six-penny finish nails driven at a slight angle. Use the manufacturer's recommended touch-up putty. Remove any excess adhesive from the surface per the manufacturer's instructions.
To insure a tight bond, cut a 1-inch-by-4-inch to a length equal to the distance between the stringers, less twice the thickness of the laminate floor – cut full - and wedge into position using scrapes of laminate flooring to protect the stringers (Photo 12). Apply constant pressure on the steps and risers with pressure shims until the adhesive cures (Photo 13). Follow the above procedure until the installation is complete. The first step may require a different stairnosing and/or installation procedure to allow the natural expansion and contraction of the laminate flooring.
Technology is allowing this process to become easier. Mohawk Industries, Inc. recently commissioned Floor Covering Services & Consultants to develop a universal flush mount stair nosing that would accommodate both conventional, pre-fab staircases with bullnose steps and the old, on-site 2”x12” built steps. The goal was to reduce installation time, guarantee safety, and provide a molding that would perform while delivering clean, smooth lines (Photos 14 and 15). The installation procedures are the same, except the flush mount stair nosing eliminates the need for bullnose removal. The molding still provides a skirt that covers a full 1 ½-inch step and the riser laminate (Photo 15).
I hope this article makes your next closed staircase laminate installation profitable and easier. Remember to always follow the specific installation instructions for each laminate manufacturer when installing laminate flooring on steps.