How to Sandwich Plywood & OSB Together

Typical OSB panel.

Oriented strand board or OSB is less expensive than plywood but does not have an attractive appearance. Plywood is sometimes added as an outside layer to give a more aesthetically pleasing finishing effect for the desired panels. The process of making a plyood and OSB board panel requires a large area with plenty of room to work and no concern for what can be a messy process. Heavy weights of various types are used in the sandwiching process.

Things You'll Need

• level concrete surface, like a garage floor
• steel measuring tape
• plywood panels, 48 inches by 96 inches, 1.4 inch thickness
• OSB, wood fiber strand board, same size, 5/8 inch thickness
• heavy bristle push broom
• 2 clear 1 mil plastic painter's drop cloths
• liquid concrete floor cleaner
• large ventilation fan
• manufacturer's recommend adhesive similar to Gorilla Glue
• long handled squeegee for wallpapering
• plastic clear sheet, same size as plywood and OSB
• concrete blocks
• glue cleanup rags
• ventilating fans

Instructions

1. 

   Measure the plywood and OSB board at the store where you plan to purchase it.

   Decide on the size of sandwiched OSB-plywood panel you need. Home improvement stores sell pre-cut sizes of both OSB and plywood of various thicknesses from which you can choose. They usually pre-cut them in two-, three-, four-, and six-foot square pieces. If you need a full sheet it will be 48 inches by 96 inches with several thicknesses available from 1/4 inch to 3/4 inch in most stores. Choose the size you need from the store stock on hand to save cutting and according to your materials budget. You may want to try the sandwich process on the smallest-size OSB and plywood panels available to make sure you get the hang of the process, then move to the larger size you need for your project.

2. 

   Sweeo up the floor before beginning this project.

   Clean the floor first. Use a hard-bristle push broom to sweep up debris and any deleterious material from the surface of your concrete floor. Then use a liquid concrete cleaner that dries rapidly. Ventilate with a fan and let dry completely for several hours until odor is gone.

3. Lay down the clear plastic painter's drop cloth. Then place the OSB panel over the center of the plastic drop cloth. The painter's cloth can be thrown away later during clean-up after making sandwich panels. Sweep and wipe off the OSB surface to receive the plywood sandwich panel after applying glue to the OSB panel.

4. 

   Use trowel instead of squeegee if desired.

   Spread glue liberally, then squeegee into a uniform layer over the entire OSB panel. Wipe off excess glue at panel edges. Follow glue manufacturers' recommendations on waiting time before placing the plywood sandwich panel over the OSB panel.

5. Carefully place the plywood panel over the OSB panel after waiting the appropriate time for glue to set up. Line up the plywood with the outside edges of the OSB panel. Usually it only takes a minute or less for the glue to be ready to receive the plywood panel. Get ready and be prepared with cleaning rags to wipe up excess glue that will appear when the panels are sandwiched together. Wipe glue completely off edges and the exposed finish surface of plywood. Be prepared to place the second sheet of painter's drop cloth onto the exposed surface of the glue-free plywood panel. When the glue is wiped off the exposed plywood, place it on the painters' drop cloth.

6. Place clear plastic panel over the plastic drop cloth on the plywood surface. Be sure all glue has been wiped up completely before the drop cloth is placed on the plywood. Line up the plastic panel with the sides of the plywood panel as you did with the OSB panel. Check all edges for the proper straight-edge alignment of the OSB, plywood and plastic panels.

7. 

   Use old bricks and stack them to save money.

   Carefully place eight inch by eight inch by 16 inch concrete blocks adjacent to each other on top of the plastic panel, covering the panel completely. Add asecond layer of blocks aligned in the opposite direction. Visually check the edges of the sandwiched panels of OSB and plywood to see that panels are pressed extremely tightly together. If in doubt, add a third layer of blocks, aligned oppositely from the previous layer. When the blocks are all laid, carefully wipe any excess glue from the perimeter of the sandwiched panel. Let dry a minimum of 48 hours or to the glue manufacturer's recommendations. Remove the blocks, painter's drop cloth and plastic panel. Sand any glue residue from the surface of the plywood and its edges. Use your new sandwich panel in your latest woodworking project.

Tips & Warnings

• Minimize the size of OSB and plywood panels to sandwich.

• Ask advice on adhesives and glues from a home-improvement store clerk.

• Make sure your work area has sufficient room around the panel work area.

• Clean up thoroughly before the glue sets.

• Do not try to reuse old painter drop cloths, they may have undesirable residue on them.

• Avoid breathing any glue fumes and ventilate thoroughly during the panel making process and while glue is in its final setting period.

References

• Ask the Builder: Plywood and OSB
• The Engineered Wood Association: Oriented Strand Board