Installing drywall over plaster is an efficient way to refresh old walls and ceilings without removing the existing plaster. Often used in older homes, plaster can crack and fade over time.
Covering it with drywall is cost-effective and can restore the walls’ appearance and strength. Below is a detailed guide on how to hang drywall over plaster.
Let’s get straight to the point.
Covering old plaster walls with drywall is an efficient way to refresh and modernise a room without the hassle of removing plaster. Start by securing any loose plaster with screws, then measure, cut, and install drywall sheets over the existing surface.
Use drywall screws to attach it to wall studs, tape and mud the seams, and trim mouldings and baseboards to fit. Drywall is cost-effective, easier to install and repair than plaster, and provides a smooth, modern finish that can be painted or textured.
Why Cover Plaster With Drywall?
Plaster, particularly in older homes, can lose its charm and develop cracks due to the building’s natural settling. Repairing plaster can be expensive and time-consuming, so many opt for drywall.
Not only is drywall cheaper to install, but it’s also easier to work with. It gives your walls a fresh and modern look. Installing drywall directly over plaster saves time and money and reduces the mess of removing old plaster.
Tools And Materials You’ll Need
Before starting the project, gather the following tools and materials:
- Multi-purpose knife
- Drywall screws and plaster screws
- Plastic washers
- Tape measure
- Pencil
- Pry bar
- Utility knife
- T-square
- Drywall sheets
- Drill
- Stud finder
- Drywall hoist or “deadman”
- Fibreglass mesh tape
- Joint compound (mud)
Preparation: Secure The Plaster
1. Check For Loose Plaster
Before installing drywall, check the existing plaster for loose areas. It needs to be secured if the plaster is crumbling or not firmly attached. Scrape off any flaking plaster with a utility knife.
2. Use Plaster Screws To Secure Loose Plaster
Use plaster screws with plastic washers to secure loose plaster to the wooden lath strips underneath. These screws prevent further cracking and provide a stable surface for drywall installation.
3. Remove Baseboards And Mouldings
Carefully remove baseboards, crown mouldings, or window and door casings with a pry bar. Be cautious during removal to avoid breaking these trim pieces, as they can be reused later.
Finding Studs And Preparing Drywall
4. Locate Wall Studs
To secure the drywall properly, you must know the studs behind the plaster. Use a stud finder or mark the stud locations using the existing baseboards as a reference point.
Mark these points with a pencil for easy reference when attaching the drywall.
5. Measure And Cut Drywall
Accurate measurement is essential to avoid wasting materials. Measure the wall’s height and width, then cut your drywall sheets to size.
Use a T-square and utility knife to score and snap the drywall along your measurement lines.
6. Cut Openings For Electrical Boxes And Fixtures
Use a jigsaw or handsaw to cut holes in the drywall for electrical outlets, switches, and light fixtures. Make sure these openings are precise, as mistakes can be difficult to fix later.
Installing Drywall Over Plaster
7. Apply Adhesive
Before screwing the drywall into place, apply a generous amount of Liquid Nails adhesive to the back of each drywall sheet. This extra step helps the drywall bond better to the plaster, reducing the number of screws required.
8. Position The Drywall
Place the first sheet of drywall horizontally, starting at the top of the wall. Use a drywall hoist or deadman to hold it in place while you secure it.
Have a helper to hold the sheet while you work.
9. Screw The Drywall Into Place
Use 2-inch drywall screws to fasten the sheet to the wall studs behind the plaster. Screws should be placed every 6 inches along the studs, ensuring each screw is at least 3/4 inch from the edge of the drywall.
Countersink the screws slightly to avoid them poking through the surface.
10. Leave A Gap Between Panels
When installing multiple drywall sheets, leave a small gap between the panels—about 1/8 inch—to allow for expansion. You can fill these gaps later with joint compound and tape.
Finishing The Job: Taping And Mudding
11. Tape The Seams
Once the drywall is in place, tape all seams and joints using fibreglass mesh tape. This type of tape provides extra strength and prevents cracking.
12. Apply Joint Compound
After taping the seams, apply a joint compound (mud) layer over the tape. Smooth it out using a drywall knife and allow it to dry.
Once dry, lightly sand the compound to ensure a smooth surface. If necessary, repeat the process for a second coat.
13. Check For Gaps Or Imperfections
Inspect the wall for any visible gaps or imperfections. If needed, apply additional compound to fill in any areas you missed. Once the compound is dry, sand these areas smooth.
Addressing Special Considerations
14. Electrical Fittings
Since the drywall adds an extra layer to your wall, electrical boxes may now be recessed. To bring outlets and switches flush with the new drywall surface, use electrical box extenders, available at most hardware stores.
15. Window And Door Jambs
If your window and door jambs are too short due to the extra thickness of the drywall, install jamb extenders. These can be custom-cut to match the dimensions of your existing frames.
16. Trimming Mouldings And Baseboards
Once the drywall is secured, you must trim and reattach baseboards, crown mouldings, and other trim. Since the wall is now thicker, you may need to trim down the lengths of these pieces to fit the new wall dimensions.
Drywalling Over Plaster Ceilings
17. Secure Loose Plaster On Ceilings
Plaster ceilings can also be covered with drywall, but any loose plaster must be reattached first. Use plaster screws to secure the plaster to the laths. Ensure the screws are long enough to penetrate both the plaster and laths.
18. Find Ceiling Joists
Use a stud finder or exploratory holes to locate ceiling joists. Mark the centre of each joist with chalk for easy reference when screwing the drywall in place.
19. Install Drywall On The Ceiling
Raise the drywall into position using a deadman or drywall hoist. Start by securing screws into the centre of the panel, then work outwards. Be sure the screws are flush with the surface but not too deep to avoid damaging the drywall.
Benefits Of Drywall Over Plaster
20. Improved Appearance
Drywall provides a clean, smooth surface that can be painted or textured to match your preferred style. It can make a room look modern and refreshed, especially in older homes with deteriorated plaster.
21. Fire Resistance
Drywall has fire-resistant properties, helping to slow the spread of flames in a fire. Special fire-rated drywall, known as Type X drywall, is available for areas where enhanced fire protection is needed.
22. Cost-Effective Solution
Covering plaster with drywall is more affordable than repairing or replacing plaster walls. It also saves time, as installing and finishing drywall is generally quicker than plastering.
Conclusion
Hanging drywall over plaster is a practical solution for restoring old walls and ceilings. It’s a cost-effective method that enhances a room’s appearance while saving time and money.
By securing the existing plaster, carefully measuring, and following the steps above, you can install drywall that looks professional and lasts for years to come.
Drywall offers a modern, sleek finish that is easy to maintain and repair—making it an excellent choice for homeowners looking to refresh their living spaces without the hassle of removing old plaster.
Frequently Asked Questions About Plaster
Is Drywall Installation In The Bathroom Permitted Over Plaster?
It is possible to instal drywall over plaster in a bathroom; however, you will need to use a green board resistant to mould. Plaster, on the other hand, does not have pores and does not support mould growth, in contrast to drywall, which does. Therefore, utilise a drywall product designed specifically for use in bathrooms for added defence against it.
Drywall Of 14 Or 38 Of An Inch Over Plaster?
When installing drywall over previously constructed walls, you must use the narrower 14-inch variety of the material. If you use thick drywall, the electrical boxes and light switches will have to be installed too far back in the wall. Therefore, you are going to have to have them repositioned.
If you decide to use thicker drywall, you should prepare for the possibility that the electrical boxes will need to be moved forward and that you will need to use longer screws to access the studs.
Is It Necessary To First Remove The Old Plaster?
Plaster, being brittle and rigid, is susceptible to cracking due to the normal settling in a house. Therefore, before attaching new drywall panels, removing any old plaster may not be required in all cases; however, doing so may be recommended in certain circumstances.
Is Drywall Capable Of Being Screwed Over Plaster?
When a room has older plaster walls that are damaged somehow, one option for sprucing it up is to instal drywall on top of the plaster already there. The walls are given a smooth, clean surface ready for new paint, paper, or trim after an overlay of drywall is applied.
How Can I Locate A Joist When The Ceiling Is Covered In Plaster?
If you want the light to appear nearly horizontally across the ceiling, you should hold a flashlight right up against it at a very gentle angle to the surface. Also, keep an eye out for bumps in the paint. They almost always point to the presence of a nail behind the plaster, and wherever you find a nail, you’ll find a joist nearby.
