How To Fix Thin Walls: Soundproofing, Insulation Tips, and More By Realtor.com

While it's fun to speculate on “if these walls could talk,” when it literally becomes the case, it’s an entirely different scenario.

Paper-thin walls in a home or apartment can trigger numerous issues, all of which can affect the residents' quality of life. From lack of privacy to lack of sleep, the frustration over thin walls can be intolerable.

Of course, homeowners have more options to combat this problem compared with renters, but they can still experience annoyance, especially in multigenerational households, which are on the rise.

For renters, the issue can be trickier. Sure, everyone hopes for agreeable neighborly relationships, but these can quickly devolve into chaos and disputes due to noise. And this can happen whether it’s noise from pets, crying babies, loud music, or arguments.

Thankfully, experts say there are ways to mitigate the problem—and the noise.

“If you've ever lived in a home where you can hear your neighbor sneezing through the wall—or worse, arguing at 2 a.m.—you know the frustration of thin walls,” says Ben Harvey, principal interior designer and CEO of Patio Productions.

This is a common issue, he adds, especially in newer builds that prioritize affordability over thick, sound-dampening materials.

“But whether you own a home and want to fix the problem permanently or rent and need a temporary solution, there are ways to reduce unwanted noise,” he says.

What counts as a 'thin wall'?

A “thin wall” is an objectionable term, but there are some standards that the building industry holds to.

Andrew Legge, CEO of Havelock Wool, a company that produces natural, sustainable building insulation made from wool, explains that a thin wall has a maximum thickness of 4.5 inches. It is typically composed of drywall on both sides of a two-by-four stud, with an air cavity in between.

“Drywall is usually obtained in quarter-inch, half-inch, and ⅝-inch thickness; ⅝-inch drywall is used for fire protection and sound suppression,” says Legge.

Thin walls are usually present in older constructions, such as those built before 2000, due to outdated building codes and materials. 

“In contrast, newer builds are more likely to use ⅝-inch drywall or even double layers to help with sound absorption,” said Harvey. “If your walls are under 4 inches thick, you’re likely dealing with excessive noise problems.”

How to soundproof a room in your house

Thankfully, if you’re a homeowner, there are many ways to remedy this situation.

Spray foam insulation

This method does not require removing the existing drywall.

“You drill holes in the existing drywall and inject the insulation to fill the cavity between the walls,” says Dean Bennett, president of Dean Bennett Design & Construction.

He notes one caveat, however: This does not work where elements like heating ducts or other plumbing are in the way.

The cost for a bedroom or office in an existing/older property (depending on the costs of materials and labor in your area and the exact size of the room) is around $2,000, he adds.

Soundproofing drywall

Soundproofing drywall can be installed over the existing drywall. While this method can help a bit, it won’t be as effective as spray foam insulation, Bennett explains.

“You also lose some space in the room, as the soundproofing drywall is ¾-inch thick,” he says.

The cost might be $5,000 to 6,000 for an office or bedroom, he adds.

 Sound batt insulation

This insulation is “made from lightweight, flexible fiberglass or Rockwool,” according to the website of Robey Inc., a drywall and insulation contractor company.

“Traditionally fabricated into rolls, sound batts now come pre-cut into standard industry sizes and are ready to install between stud framing and behind drywall," according to the company website.

These can also include mass-loaded vinyl, “another excellent material that absorbs sound and can be installed under drywall,” says Harvey.

This entails removing the existing drywall, installing this insulation, reinstalling drywall, and doing all the finish work, such as texturing, painting, and trim, according to Bennett. The cost is more than $10,000 for an office or bedroom.

Dampers

Some special dampers are available that go between the two-by-four studs (or the ceiling joists) and drywall, says Bennett.

“You would need to remove the existing drywall and reinstall,” he says. The cost could “easily reach $20,000.”

Natural wool

Legge says the optimum approach to soundproofing is to absorb, damp, decouple, and seal sound.

To that end, he adds that natural wool Insulation is better than fiberglass or foam insulation as it absorbs sound with its dense fiber construction. 

Angi notes that “the average wool insulation cost is $2,800, or between $1.40 and $4 per square foot.”

Can a ceiling be soundproofed?

In addition to thin walls, older structures in the house, such as ceilings, might also need noise mitigation.

This is particularly relevant for multigenerational households, a trend that has been resurging. In 2024, 14% of homebuyers purchased a multigenerational home “to take care of and spend time with aging parents because children over the age of 18 were moving back, and for cost savings,” according to a National Association of Realtors® survey.

Experts also have several recommendations and tips for this specific situation.

“In multistory homes and apartments, soundproofing ceilings is one of the most necessary things to do, and yes, it can be done,” says Legge. “The combination of resilient channels and double drywall minimizes footfall-induced impact noise.”

For a more DIY-friendly option, acoustic ceiling tiles or even fabric-wrapped panels can help absorb sound and make a noticeable difference, according to Harvey.

How to reduce noise problems through walls in apartments

For renters experiencing noise nuisance, tackling the problem might be more challenging, but it’s not impossible.

If permanent renovations are not possible, Michael Vitale, owner and president of Vitale Homes, which builds new single-family homes, notes that there are several ways to mitigate noise through a shared apartment wall. One of these entails using removable or temporary treatments.

“Start by placing large, filled furniture like a heavy bookcase or cabinet against the shared wall,” Vitale says. The added mass against the wall can help disrupt and absorb sound coming through the wall.

Hanging curtains or quilts on the wall can also make a difference if you don’t mind the aesthetic, he adds.

Another tip: White noise machines and soundproofing door sweeps.

These can also help mask unwanted sounds, says Harvey.

“If all else fails, a polite conversation with your noisy neighbor might work wonders (or at least help set some boundaries),” he says.

"Call Eli Torres at (832) 430-2107, for your home buying and selling needs."

Source: www.realtor.com