One of the more challenging aspects of hanging drywall is cutting around junction boxes and pipes. If not done properly the result could be an area around the box or pipe that will need to be finished with joint compound. This will be noticeable even after it is painted. So doing it right the first time is critical.
Cutting Around Receptacles
You may need to make cuts in drywall for multiple junction boxes and pipes. Outlet, light, heat vent, smoke detector, cable access and telephone boxes are the majority of type of junction boxes you will encounter. Water pipes, drains, dryer vents, gas lines and central vacuum units are common pipes that you will come across.
You will most likely have to cut both rectangular and circular holes for different receptacles. While rectangular cuts are fairly routine, cutting around pipes and round receptacles can be tricky and caution must be taken to ensure a tight fit.
Step 1 - Safety
Safety first. Since this process involves sanding and the removal of material that creates airborne dust, we recommend using safety equipment such as safety glasses or goggles, work gloves, a work apron or close fitting clothing and an approved dust/mist respirator.
Step 2 - Measuring
In this method, you need to take the measurements of the junction box to determine the distance each side of the box is away from the adjacent sheet. Many times you will be measuring from the ceiling, floor or corner to get the top and bottom measurements of the box. Once you have written down the measurements you need to transfer them to the front of the drywall sheet. ALWAYS double-check your measurements to make sure you are putting the hole in the right place. It is very easy to measure from the wrong side or edge of the sheet and you will find yourself having to cut another piece of drywall.
Step 3 - Preparing to Make the Cut
Once the measurements are on the sheet, use a Carpenters Square or T-square to draw the outline of the box. If cutting a round hole, make a square outline using the measurements, find the center of the box by drawing diagonal lines from corner to corner. When you find the center use a scriber or compass to draw the circle making sure you do not draw the circle outside of the square.
Step 4 - Cutting
After you have made you outline of the receptacle it is time to cut it out. You will be using a drywall saw, also known as a keyhole saw, for this process. Take the saw and place the point on the inside of and portion of the outline. Firmly press the handle of the saw so the saw blade cuts completely through the width of the sheet. Gently cut following the inside of your outline until the entire piece is removed. Be careful not to leave the line you have drawn as this will most likely make the hole too small and it will not fit over the receptacle.
Always cut from the front of the drywall sheet to prevent the paper facing of the sheet from tearing.
Finishing Around Receptacles
Because receptacle box covers rarely cover more than the box itself it is quite easy to cut the hole too big and need to repair the gap using joint compound. To begin make sure that the drywall around the receptacle is properly fastened tightly to the stud the box is attached to. This will ensure the drywall will be a solid base for the repair.
Step 1 - Apply Compound
Start by applying a generous portion of joint compound into the gap and onto the face of the drywall. Apply either mesh or paper tape to the joint compound making sure the tape does not exceed the area that is covered with compound. Firmly embed the tape into the joint compound so it lies completely flat against the drywall and completely covers the gap between the drywall and the receptacle box. Using a taping knife apply a thin coat of joint compound over the tape making sure there are no large ridges and that the surface is fairly smooth.
Step 2 - Sanding the Area
Once the first coat of joint compound is dry, thoroughly sand the area using 100 or 120 grit sandpaper, 150 or 220 grit sand screen or Fine sanding sponge to smooth out the joint compound. Apply a second coat of joint compound slightly exceeding the area covered with the first coat. Make sure the compound is smooth and even. When that coat is dry, thoroughly sand the area. At this point the repair should be complete. If the area still is not completely smooth and flat, apply a third coat and sand when dry. Pay special attention to properly sand and smooth the outer edge of the joint compound so that it blends with the existing wall.
Step 3 - Clean Surface
When the surface has been sufficiently sanded to a smooth, even surface, clean the drywall dust using a wet sponge or tack cloth.
Sandpaper (80, 100, 120 grit)
Sanding Sponge (fine, medium, Extra Large Paint & Drywall)
Rubber Sanding Block
Key Hole Saw
Mesh Reinforcement Tape
Drywall Knife or Compound Spreader
Tack Cloth or Sponge
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