Can You Install Drywall Over Lath? [Steps + Cost of Replacing]

With plaster and lath walls, there’s always a springy feel to the wall. Damage marks appear as cracks and bumps in the plaster especially if the lath was poorly installed. The good news is that you can repair your damaged lath easily with drywall panels. But, can you install drywall over lath?

You can install drywall over lath if it is damaged and looks unattractive. Scrape away the worn-out lath and repair the resulting area with a patch of drywall. Stabilize the old plaster then install new drywall panels for a uniform look to cover cracks and other unsightly marks on lath and plaster.

Can you put drywall over lath and plaster?

You can install drywall panels over your lath and plaster wall if it looks worn out or if there are unsightly cracks on the plaster due to settling. Drywall is a cheaper option for repairing and covering wear marks and cracks that occur when plaster settles, or even when lath cracks or is poorly installed.

While this is the cheapest and easiest way to upgrade a plaster wall to drywall, it’s a low-efficiency method if you’re looking to add insulation. Still, you can add new wiring when hanging drywall sheets over plaster by cutting through the base of the plaster.

This kind of repair, however, can be difficult for DIYers so only start this project if you’re sure you will finish the repair successfully.

Should you remove lath before drywall?

You can install drywall panels without removing lath and plaster, which makes for an easier and less messy option. You’ll need to drill a few holes in the siding to blow in cellulose fiber insulation. As a result, stud spaces remain hollow, making this method less efficient and unattractive.

Generally, there are three ways in which you can upgrade your lath and plaster wall to drywall.

Here are the options to consider:

• Installing drywall without removing lath and plaster: The first method – as already discussed – is to install the drywall panels on top of the plaster wall.
• Removing plaster and installing Sheetrock over lath: Most homeowners would prefer to remove the plaster first and install the drywall sheets over the wood lath.
• Removing both lath and plaster completely: Finally, you can also opt to take out the plaster as well as the wood lath and install your drywall above the timber studs.

By this point- you may be confused as to why some would prefer to go through the extra hassle of taking off the lath as well before installing drywall. Well, the wood lath framework may be too structurally weak due to years of rot and wear; and may not be able to properly support the wallboard sheets. Take note- however- that some modern homes have metal and rock lath. As such, it isn’t necessary to remove the lath before drywall installation in such cases.

Take note- however- that drywall installation in cases where the lath has been removed calls for lots of readjustments to properly connect to window casings and door jambs. That being said- to properly remove wood lath- follow the steps detailed below:

• Wear the necessary safety apparel including eye goggles, long-sleeved overalls, and hand gloves to prevent eye and skin injuries due to wood splinters.
• Use a crowbar and the chisel-side of a hammer to dislodge the ends of the laths from the timber studs which they’re fastened to.
• Once you’re done dislodging all the lath boards, set them aside to avoid potential foot injuries from the attached nails.

How to install drywall over wood lath

Before installing drywall, you want to check whether the wood lath is in good condition and doesn’t need to be removed and that you can install drywall over it. To do this, remove the plaster covering it first. As opposed to removing lath – which is pretty simple as detailed in the previous section- removing plaster from wood lath can be a tricky process and requires attention to detail

Here’s how to install drywall over wooden lath:

1. Prep the wall for remodel work

Undertake some prep work, which includes removing all wall décor, switching off the HVAC system, and covering HVAC vents. You should also ensure you have all the necessary tools and safety gear.

2. Tear away the plaster with a crowbar

After removing all the decor and items that you’ll need later, use a crowbar to tap through the topmost center section of the wall until you cut a hole that goes through all the way to the wood lath. Then pull the end of the crowbar downwards to tear through the plaster.

Repeat this step using the initial tear as your starting point until you’ve separated all the plaster from the lath. Note that if a crowbar can’t get the job done, try using a putty knife or a scrapper.

3. Fasten the lath strips properly

After you’ve removed all the plaster, it’s now time to install your drywall panels. Use the procedure detailed below to do this effectively:

Inspect the lath strips and make sure each of them are properly fastened to the studs. Nail down any loose lath strips and clean off dust and dirt.

4. Install drywall panels over the fastened lath

Start installing the first row of drywall sheets from one top corner of the wall. The edges of the panels should be aligned to the center of the timber studs for proper fastening.

Drive 2-inch drywall screws through the panels and into the studs, ensuring the screws are at least 6-inches apart. As you work your way from one drywall panel to the next, ensure that their edges are aligned at the center of the timber stud and that you’ve not left any visible gaps between them.

Pro tip: Always check for any plumbing leaks and fix them before installing Sheetrock panels. Moisture can easily cause damage and lead to drywall crumbling and disintegrating.

5. Install the remaining row of drywall panels

If you need to cut any panels to size to complete a row, you can simply do so using a utility knife. Once you’ve completed the first row, repeat step 4 above until you’ve covered the whole wall with wallboard.

Cost to replace lath and plaster with drywall

The average cost of replacing lath and plaster with drywall is between $1,020 and $2,800 when done by a professional contractor. If it is a DIY project, the overall cost will be $1.60 to $3.80 per square foot considering the plaster and lath removal cost and the price of Sheetrock.

It is important to note that the overall cost of replacing lath and plaster with drywall varies from one homeowner to the next- depending on the costs of lead and asbestos testing, prep work, plaster-and-lath demolition, disposal, and drywall installation.

I have broken down the costs you would expect when installing new drywall sheets over plaster and lath as follows:

• Cost of Lead and asbestos testing: – In older homes, the plaster and paint used typically contained lead and asbestos. You- therefore- need to undertake a test for the presence of these toxic substances before working on such walls. Professional lead testing for lead and asbestos costs an average of $300 and $500 respectively. This- however- doesn’t cover the cost of the associated fixes.
• Cost of prep work: – prep work expenses may involve the cost of fixing loose lath strips and the cost of removing stuff from the room.
• Cost of plaster and lath removal: DIY plaster removal is the cheapest option. However, professional plaster removal will cost you anywhere between $300-$1000 dollars. The costs only increase if the laths are to be removed as well.
• Cost of drywall panels and installation:– Drywall panel costs vary depending on size and thickness, as well as additional qualities such as water and mold resistance. A high fire-rating on drywall can also mean a much steeper cost. Meanwhile, DIY drywall installation is the most affordable option, with professional drywall installation costing anywhere from $1-$3 per square foot.

Is lath and plaster better than drywall?

Deciding on whether to go for a lath and plaster wall or drywall is usually difficult for most homeowners. While drywalls make it easier to incorporate insulation features, plaster walls boast better in terms of soundproofing and overall visual appeal. In the end the better option depends on what you’re looking for.

Read More: How to Dry Joint Compound Faster