How To Repair Small Cracks in Drywall
Small cracks, called stress cracks, commonly occur around door and window openings. They are usually the result of movement of the wall or structure; typically from settling and wood shrinkage. Simply painting over the crack or filling it with spackling paste often will only hide the problem for a short time. Follow these instructions for a longer-lasting repair.
If the crack occurs over a seam between drywall panels, cut out any loose drywall tape and other loose material. Press on the drywall panel to determine if there is any movement. If so, start by driving a new fastener nearby. It will be necessary to determine the location of the stud behind the drywall, so that you drive the new screw into a solid support. As you begin driving the screw, use firm pressure with your other hand to snug the drywall against the supports. If there is no movement of the panel, you can proceed to the next step.
Use a razor-knife to make a small "V" groove down the length of the crack. This will provide for better adhesion of the joint compound. Fill the groove and any voids with joint compound and cover it with mesh drywall tape. The tape proves a substrate for the compound to adhere to, resulting in a smoother, stronger patch.
Next, using a 3" putty knife, spread a coat of joint compound over the mesh tape and allow it to dry. After the compound has dried for at least a couples hours, lightly sand it smooth. Wipe away any dust and apply another coat of joint compound. Taper the compound at the edges to blend it with the surrounding surface. Allow this coat to dry and then sand.
Finally, apply a third coat of joint compound. With this coat, it will be necessary to blend it with the surrounding decorative texture. There are many different textures, so we can't list all of them here. However, matching a texture can sometimes be done by dragging the compound around with a putty knife, dabbed with a moist sponge, or sprayed on with off the shelf products designed to retexture small patches.