Can you paint over wallpaper?

Painting over wallpaper is something that people do to save time when they want to improve their house.
It can be done and most of the times comes out fine.

There are instances though that you have to remove the wallpaper in order to achieve a smooth finish. If the wallpaper has a heavy texture then you’re most likely better off to remove it.

When you paint over heavy texture wallpaper there are two disadvantages, 1 the texture will show through, which is fine most of the times, 2 where the wallpaper is damaged you will need to patch and the patched area will look different after you paint.

If the wallpaper is smooth (no texture) you can patch without worrying that the patched area will come out different than the rest of the wall.

How to paint over wallpaper?

Today’s question comes from Aaren. Aaren asks:

Hi hope you can help! My daughter’s room will not stop smelling. In fact, I challenged Olympic Paint and Lowe’s – going back and forth until we settled. KILZ and another coat of paint reproduced the original smell! Olympic even paid a professional to do all that work for us. The second coat of Premium One water based latex interior paint still smells. We have 2 air purifiers and had our windows opens for a week while painting and for 12 days afterward. …. As of today however we are dealing with a smell from Friday. It’s awful and I’m afraid to let my daughter sleep in there (although she has for two nights). WHAT can I do to make it go away. The room seems like it’s cursed. No other room in our house ever smelled like this… Please help with ideas of what to do. How long is this supposed to last. The smell is like a sweet, clay smell. It doesn’t really smell like paint at all. We even crawled into the attic to check for smell and it wasn’t present. We tried sprays, onions, vinegar, steam cleaning. Everything. Your advice would be greatly appreciated. Many thanks. Aaren

The E D Painting Expert Answer 

Hi Aaren. When we first answered this years ago, it was a rare issue, but over our 22 years in the painting industry, we’ve seen this exact scenario pop up a few times. That “sweet, clay-like” or sometimes “sour” smell that lingers for weeks is incredibly frustrating.

Based on your description, you are likely dealing with one of two specific issues:

1. “Sour Paint” (Bacterial Contamination) Water-based latex paints can actually “go bad.” If bacteria get into the paint at the factory or the store, it starts a reaction that smells exactly like sour milk, clay, or dirty socks. Unfortunately, no amount of air purifiers or open windows will cure this, because the smell is baked right into the dried film on the wall.

2. The “Wall Odor Phenomenon” Sometimes, the chemicals in new low-VOC water-based paints react with the invisible residues left on the wall from older paints, creating a chemical off-gassing that smells sweet and pungent.

Here is the problem: you mentioned the professionals applied a coat of KILZ. If they used a water-based latex KILZ primer, it will not block the odor. Water-based primers allow the smell to breathe right through them.

How to Fix the Lingering Paint Smell

To permanently kill this odor and make the room safe for your daughter, you have to seal the wall so the smell cannot escape. Here is the professional procedure:

1. Dehumidify the Room: Close the windows. High humidity (especially if you live in a humid area like we do here in New England) keeps the paint pores open. Run a strong dehumidifier for 48 hours to pull all the moisture out of the walls.
2. Seal with BIN Shellac-Based Primer: You need to apply a coat of Zinsser B-I-N Shellac-Based Primer (or a heavy-duty oil-based stain blocker). Shellac is what professionals use to seal in heavy smoke damage and severe odors. It creates an impermeable barrier that the clay smell cannot penetrate. Note: Shellac has a very strong alcohol smell when applying, but it dissipates completely once dry. Do not use a water-based primer here.
3. Apply Your Final Topcoat: Once the Shellac is 100% dry and the room is aired out, apply a fresh coat of high-quality, premium acrylic paint. (If you aren’t comfortable doing this yourself, our residential painting services handle this exact process safely).

Need Professional Painting Help in Hartford County, CT?

Fixing a botched paint job or dealing with mysterious wall odors can be a nightmare. If you are located in our service area of West Hartford, Farmington, Avon, or the greater Farmington Valley, you don’t have to tackle this alone.

With over two decades of experience, E D Painting knows how to prep, prime, and paint your home correctly the first time. Give us a call at (860) 989-6517 or request a free consultation online!