In remodeling you sometimes decide to bridge the new work to old or existing work. Matching or changing your wall surface becomes a consideration. This is a short guide on skim coating existing walls to match the new construction.
The previous wall surface is a heavy knockdown texture. Basically what happens is that the walls are taped and second coated, and then taping mud is thinned and sprayed on the walls with a texture hopper, and after a few minutes, it is ‘knocked down’ with a taping knife resulting in a textured wall. It is a cheap finish system and all too often is done badly.
This is the alcove where the toilet sits in the Lightyear Sunken Bath Project. In this case we decided to make the walls smooth. This has just about every thing you can run into when remodeling with drywall between old and new construction.
The left of this photo shows the edge of the drywall that covers where we installed a pocket door. The back wall shows where we installed a glass block for light and replaced the piece of drywall we cut out previously. You can also get a good idea of the ‘knock down’ texture.
The right side shows where we framed up the new partition between the toilet and the shower with the opening for the open shelf unit.
Here is the beginning of taping this area. We use mesh tape for the flats, and paper tape for the inside corners. Taping on texture has its own issues. When you feather your mud, the knife running over the texture telegraphs and creates ripples in your mud coat.
When taping inside corners on these areas, mud and embed your tape, and wipe down the new flat side first. This creates a guide area for wiping down the other side and give you a clean smooth corner.
Here the process is a bit further along with the introduction of the open shelf unit and the metal bead. This unit is trimless, so I installed ‘L’ Bead along the outside edges of the shelving unit. Not shown in this photo is a piece of mesh tape applied diagonally just below the high side of the bead. This strengthens the joint, minimizing cracking, and reinforcing the gap made by the bead and the drywall. We also taped the flats and installed the corner bead.
Look at the bottom of this photo and notice the grey triangular area. This is where I did not cut through the corner deep enough when I removed the old drywall prior to rebuilding this.
Here is where I have prefilled this area thinking that I had gotten all of the loose paper removed. Bzzt! not so fast. You can see the bubbles from a bit of the paper that had separated. You have to remove these and fill them in. If you do not, succeeding coats of mud will bounce, and look bad. You can also get an idea of the texture filling with the splotchy area outside of the triangle.
Here is where I have taped the flats and the corners. You can see the diagonal line of where the two ‘L’ beads do not match up perfectly. This will be fixed on succeeding coats. The magazine rack also gets taped. If it is an inside corner it gets tape.
The most important part of skim coating is taping the inside corners to provide clean sharp angles.
Once your corners are done, you can then begin the process of skim coating to smooth your walls.