Home Inspection - Looking For Defects on Drywalls And Plasters | Propertylogy

Home Inspection – Signs Of Defects On Drywalls And Plasters

By on June 25, 2017

There are basically 3 most popular types of wall finish surfaces found in the average house. This is without mentioning some houses belonging to the rich and wealthy who might get walls erected made of stone or even plated with gold.

The 3 are:

  1. Concrete with and without acoustics
  2. Plaster
  3. Drywall

Concrete is very durable. And it usually will take the presence of a major problem for defects to show. This also means that if there is a noteworthy problem with a concrete wall, it should be blatantly obvious unless you were busy scrolling your social newsfeeds when you should be inspecting.

This leaves the remaining 2 which is the focus of this discussion.


Plaster has been used in homes for a very long time. The glue-like substance is traditionally applied after wood or metal lath is fixed to the framing. In certain cases, even over brick.

The first thing you have to do is determine whether it is plaster.

After drying off, a plaster wall is usually tougher and thicker compared to drywall. This causes a more uniform sound when you rap across it. And as if physics is playing a trick on you, it would like cement to the touch… making it more fragile.


Due to it’s brittle characteristic, plaster can be very prone to hairline cracks. This does not necessarily mean that there is a big issues. A lot of times these minor cracks can be rectified with cosmetic touch ups.

When you find a crack, subtly use a little force to press down on both sides of the crack. If it moves, this would mean that the plaster has detached from it’s latch.

If it is not detached, the crack is most probably caused by the expansion and contraction of the house due to climate and seasonal changes. In this case, all you might need to do is seal the cracks with flexible elastomeric caulk.

Larger cracks can appear when there is structural movement. And diagonal cracks often spruce up originating from the corners of windows and doors. Diagonal cracks is a sign that one end of the header is sinking while the other end is not.

There might be various causes of this. One of which… that you don’t want to hear… is foundation failure…

You might want to get a qualified structural engineer to make an assessment.

Saying this, regular cracks are a common place for plaster ceilings in older homes. It’s just natures way of reminding us of who’s boss.

If they are not serious, you could get away from a huge bill by re-attaching the plaster to the lath. Or you might overlay it with drywall which we will talk about later.

Mold and water stains

Water stains are most often caused by too much moisture in the interior. The ventilation within a house will play a critical role in this.

It could also be caused by other defective areas of the house like:

  • leaking roofs
  • leaking windows
  • leaking pipes
  • etc

You might feel that a few water stains here and there is no big issue. They add to the natural ambience of the home anyway.

But what you are really looking out for is conditions for mold to thrive. Leaving moisture unattended to is basically inviting in the mold.

The good news is that plaster in it’s form is actually very resistant to mold. Mold found on plaster is usually growing on residue left on it’s surface. So simple housekeeping might solve the problem.

However, it is not impossible for mold to build a city of it’s own on plaster walls. If this is what you find, you could have a problem that has been brewing for quite some time already.

In this case, it might be time to call in the calvary and hire a mold-remediation contractor.


As mentioned earlier, plaster has been used in homes for a very long time. It is only in recent decades where drywalls have hit the mass market.

Drywall is typically installed by affixing panels together with wall studs or ceiling joists. Some contain paper material within it, while others don’t.

It is easy to install and does not apply wet like plaster. Hence the name, drywall.

And again. The first step is to determine whether you are working with drywall.

Because it is cheaper to install, most houses built after the 1950s have drywalls. They finish with a much smoother surface compared to plaster.

However, the best manner to expose the presence dry wall is knocking across it’s surface. Because unlike plaster which has a consistent sound, rapping across a drywall panel will create a hollow sound… until you reach a stud. Then it will sound obviously less hollow.

Exposed and protruding nails and screws

This is a common defect caused by shoddy workmanship. The installer either drove them too deeply, or did not use enough of them.

If you find pull-throughs of nails and screws coupled with observable gaps at the top and bottom of the wall, it could mean that the lumber is shrinking. This can happen when green lumber was used instead of kiln-dried lumber.

In this case, you have to allow the shrinking to finish shrinking before carrying out repairs. Or else the problem would repeat itself.

When these nails and screw pops are found in the ceiling, it could mean that there is joist flexion. The joist used are not strong enough to support the weight carried above.


Unlike plaster, drywall is very resistant to cracks. So much so that hairline cracks can often be ignored without repercussions.

Cracking along panel seams is probably caused by bad workmanship again. So is joint tape coming off.

Drywall joints that are incorrectly aligned with the framing of doors and windows can cause vertical cracks to appear at… where else but the doors and windows.

Larger diagonal cracks that run from a starting point at windows or doors can point to a problem with structural movement. And like the case with plasters, the expertise of an engineer might be required.

If diagonal cracks appear away from doors and windows, together with the existence of a sloping floor, it could also point to a structural problem.

Mold and water stains

Similar to plaster, the cause for water stains to drywall are quite similar. The house needs to be property ventilated.

The difference is that drywall is more vulnerable to mold compared to plaster. This is due to the materials used in drywalls.

This means that if you are inspecting a house with drywalls, it might be necessary to move furniture in order to look for mold. They can often be found at the area below the lower corner of windows.

Mold can cause drywall to deteriorate badly. And if you see a bad case of infestation, the odds are that you are only seeing the tip of the iceberg.

You might need to call a mold-remediation contractor for help.

Picture on wall

Sometimes sellers keep art, posters, framed images, and pictures on the wall. Don’t make the mistake of ignoring them.

They could very well be strategically positioned there to hide defects on the wall. So do look behind hanging pictures for a quick scan just in case.

Other common surfaces

What if there is no drywall or plaster?

Without going overboard with possible surfaces, the 3 most common used in homes these days are:

  1. Vinyl wallpaper
  2. Regular wallpaper
  3. Wood paneling

The most common defect for vinyl wallpaper is something homeowners often call “blistering”. This a dominant, but not exclusive, to more humid regions. The wallpaper needs to be stripped, then moisture and mold removed.

Regular wallpaper is also susceptible to mold. But the sign they give out tend to be pinkish and purplish stains that bleed through the wallpaper. The same has to be done. Strip, remove, replace.

With wood paneling, you can easily test it’s integrity by pressing it with your palms. If it flexes, it could be a result of bad workmanship, or it might be installed directly over a drywall or plaster. This is a suspicious indication that the original wall the paneling is covering up could be in very bad condition.


Without going deep into definition here, note that some people call certain types of walls false walls and stud walls.

Some are meant for cosmetics purposes like a feature wall used commonly in the living room behind the TV set. Drywalls and plasters are usually meant to blend into the interior design without standing out as something extra that didn’t come with the house originally.

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