Since drywall isn't only installed in the walls, adding a double layer of drywall to ceilings can be particularly advantageous in multilevel buildings with different residences. In other words, think of the benefits it offers for apartment buildings.
Double or multiple layers of drywall are sometimes required for increased fire resistance or for reduced sound penetration.
Yes, you can install new drywall over an older ceiling or walls. This is often done when the work involved in renovating an existing surface is more work than it is worth. In some cases, it can help renovate a surface that is uneven, sunken, loose, or that contains materials such as asbestos.
The average cost to install drywall includes materials and labor and runs between $1.50 and $3 per square foot. That equates to about $60 to $90 per drywall panel.
Drywall can be hung horizontally or vertically. Most is hung horizontally so that a sheet of it spans more than one set of supporting studs, but if one wants to set sheets vertically there is nothing prohibiting doing that.
On this basis, a stack of drywall (laid flat) should not exceed approximately 9” in height (example: 18 sheets of 1/2” drywall or 14 sheets of 5/8” drywall). In some areas, it is common practice to temporarily shore up the floor system in order to stack more than 9” of drywall.
Add Additional Sheets of Drywall
A longer wall may need more than one sheet of drywall. Using a drywall lift can make this step easier. Start by hanging a full sheet as before. Tack it in place, and then drive drywall screws every 16 inches and into the studs.
One key difference between the two is that sheetrock is a brand name of drywall made by the United States Gypsum Corporation. Another difference lies in their production process; sheetrock has a slightly denser core than drywall due to the addition of a small amount of wood fiber to the gypsum core.
1/4-Inch Drywall: The thinnest of all the options, 1/4-inch drywall is most commonly used as a skimming material. Mount it over an existing layer of wall to refresh the look and hide old blemishes. It's ideal for walls with a subtle curve to them.
Keeping the joints between sheets of drywall too close is an invitation for troubles along the way. Professional drywall installers allow for ⅛-inch space between sheetrock placement, and this allows for expansion and contraction for the frame of the building, avoiding cracks and damage to the drywall.
In certain cases, putting new drywall over old drywall is a cost-effective and speedy way to refresh a room. A few of the advantages of putting drywall on drywall include: It's less extensive than tearing out and replacing existing drywall. It can help soundproof a room.
1-hour fire-rated wall: Apply three layers of ⅝" Type X gypsum board on one side. 2-hour fire-rated wall: Apply four layers of ⅝" Type X gypsum board to one side.
Hang the Ceiling First
This makes it much easier to manage and attach the panels since you will not have to fumble around with the screws, measuring tape, and so on. Screws for drywall lids should be placed no closer than 16” from the wall. This allows the drywall to have a bit of flexibility to prevent ceiling cracks.
It's best to start by repairing any cracks or holes in the wall. Sand and wipe the entire wall down. Apply a coat of drywall primer and allow it to dry. Roll and brush on 2-4 coats of paint.
While drywall alone can hold about 1.6 pounds to 2 pounds per square foot, mounting an object to the stud with the proper hardware allows the drywall to support up to 100 pounds.
If you use the double-drywall technique and put a further layer of sound-dampening material or compound between them, you'll have a quieter area. The added layer of drywall and compound reduces vibrations and (consequently) cuts down on the sound that travels through the walls.
Normal drywall joints
Where two tapered edges of drywall meet, they create a shallow recess that makes taping easy. Just drag your knife over the joint and—after the third coat of mud—you'll have a perfectly flat surface. Here are a few tips for improving your taping drywall skills and increasing your speed.
Always leave a 1/2-inch gap at the floor. This allows for floor and wall expansion without cracking the drywall. It also helps prevents moisture wicking if the floor floods. Wear work gloves, safety goggles and a dust mask when hanging drywall.
Hides uneven studs – Hanging horizontally also allows the drywall to flow over the framing so that bowed studs create less of a problem. If the drywall were hung vertically and a seam placed on a bowed out stud, the seam would be magnified because of the bump in the wall.
Gypsum board shouldn't be stacked on its edge. Limit a drywall stack to no more than 17 feet high, and avoid sagging by placing risers at even distances underneath any stack of drywall.