previous
  • How to Install Housewrap Solo
    How to Install Housewrap Solo
  • Master Carpenter Videos
    Master Carpenter Videos
  • Magazine Departments
    Magazine Departments
  • Shorten a Prehung Door
    Shorten a Prehung Door
  • Clever daily tip in your inbox
    Clever daily tip in your inbox
  • Tips & Techniques for Painting
    Tips & Techniques for Painting
  • All about Roofing
    All about Roofing
  • Video: Build a curved step
    Video: Build a curved step
  • 9 Concrete Countertops Ideas
    9 Concrete Countertops Ideas
  • Buyer's Guide to Insulation
    Buyer's Guide to Insulation
  • Read FHB on Your iPad
    Read FHB on Your iPad
  • 7 Trim Carpentry Secrets
    7 Trim Carpentry Secrets
  • Deck Design & Construction
    Deck Design & Construction
  • Remodeling in Action
    Remodeling in Action
  • Basement Remodeling Tips
    Basement Remodeling Tips
  • 7 Small Bathroom Layouts
    7 Small Bathroom Layouts
  • The Hobbit House and More
    The Hobbit House and More
  • Energy-Smart Details
    Energy-Smart Details
  • 12 Remodeling Secrets
    12 Remodeling Secrets
  • The Passive House Build
    The Passive House Build
  • Play the Inspector Game!
    Play the Inspector Game!
  • Electrical Articles & Videos
    Electrical Articles & Videos
  • 7 Smart Kitchen Solutions
    7 Smart Kitchen Solutions
next

Flattening warped plywood

Even new plywood can warp if not stored properly or if left in the sun. Before you give up in frustration, though, try a little moisture therapy.

Like the underside of a shriveling leaf, the plywood’s concave side has lost moisture and shrunk. Reversing the warp can be accomplished by adding moisture to this concave side and drying the convex humped side. I use a sponge or sprayer to wet the concave side of the plywood (hot water works best). Then I lay the sheet, moist side down, on a shop floor or a driveway. Now the sun, or the warm interior air, helps to dry out the convex, humped side of the plywood. At the same time, moisture is being absorbed into the concave side. This process works faster than you can imagine, so keep an eye on the material. If it warps the other way, just reverse the process.