Hammock or Ohio Patch
A hammock patch is not as well known as either the strapped backing patch or the California patch. The name Hammock patch describes the method used. It is used in Northeast Ohio as a quick and easy method for patching small to medium sized holes in drywall or plaster walls. It can be used where there are no good options for drywall backing. A hammock patch uses the stability of the surrounding drywall to hold itself in place similar to the way a California patch is secured, however it is more secure since it is supported on both the front and back sides with mesh tape.
Cut a piece of drywall to the exact shape and size as the hole being repaired. If the hole was created intentionally, for example to access electrical wires or boxes in the wall, it is likely that the piece of drywall cut out can be used for the patch. If a new piece of drywall must be cut, try to match the shape and size of the hole as closely as possible. It is not necessary to match the thickness of drywall used. For example, if the wall being repaired has half inch drywall, it is not a problem if you use five eighths inch drywall to make the repair.
Cut a few strips of mesh tape approximately 4 inches longer than the width of the piece of drywall you will use for the patch. Cut enough strips to lie side by side on the back side of the drywall patch. See picture for details. Leave the mesh tape hanging off of both ends equally long.
Use hot mud (quick-setting drywall compound) to mud-in the mesh tape securely to the back side of the drywall patch. These strips of mesh will provide backing support to prevent the patch from being pushed in from the front.
Place hot mud (quick-setting drywall compound) on both sides of the wall surrounding the hole. The long ends of the mesh tape will be set in this mud securing them to the wall surrounding the patch. The mesh tape strips will act like a hammock for the drywall patch as if it is hanging in the drywall hole.
Place the hammock patch in the hole in the wall being careful to allow the mesh strips from the back side of the patch to fold through the sides and out the front. Set the long ends of mesh tape in the mud on the wall and wipe off excess mud. Using a six inch drywall knife, secure the mesh tape strips in place.
While setting the mesh tape strips in the hot-mud, make sure the elevation of the drywall patch matches that of the surrounding drywall. If the patch is sticking out too far from the surface, push it in slightly, if it is indented from the surface, pull the mesh tape strips to draw-out the patch closer to the surface. Ensuring that the hammock patch is sitting perfectly level with the surrounding surface on all sides will help to ensure that you can finish the patch so that no-one will be able to tell it was ever there.
Place more mesh tape on the surface of the hammock patch and surrounding drywall. This mesh tape will provide support to the patch on the front side, preventing it from falling out of the hole. It will also strengthen the seams between the surrounding drywall and the newly placed hammock patch.
Bed in the mesh tape with hot-mud on all sides of the hammock patch. Take care to remove any excess. Leave only enough drywall mud for the tape to sit in. Allow the hot-mud to harden before moving to the next step.
Using lightweight all-purpose or all-purpose drywall compound, apply 2 or three very thin layers of drywall mud to the surface of the patch. Make sure to allow the mud to dry between coats. For quicker results you can use hot mud for all finish coats however, you may need to use a couple of skim coats to achieve the same level of smoothness when matching smooth wall finishes.
For best results use a ten inch, or larger, drywall knife, to apply the second and third coats. The key to applying these surface coats is to use just enough mud to cover the underlying layer of mud while not building up the surface too high.
Once everything is thoroughly dry, sand the hammock patch lightly with 150 grit sandpaper to remove any lat marks or knife scratches. Using high quality paint, apply primer to the patch before finish coat painting to match the existing wall. For best results you may need to re-paint the entire wall with the final coat. This will help to blend both the texture and color of the new paint on the patch with that of the existing surface.
If the existing surface is textured, you may want to read this article on matching existing drywall textures. It explains some of the most important keys to matching any type of drywall texture. If you are patching a smooth surface, it is important that you take care when choosing a roller cover so the texture of the paint and primer on the drywall patch will match the surrounding wall. You may also want to read this article on level five finishes for the smoothest of drywall surfaces.