Why Your Walls Smell Musty Under Wallpaper
A musty or sour smell around wallpapered walls often comes from old wallpaper paste breaking down, especially where damp has gotten behind the paper, sometimes with mold growing in the glue and on the wall. Address the moisture and the paper, and it clears.
We make small-batch beeswax candles in Far Rockaway, so a room that truly smells clean is our whole focus, and that always starts at the source rather than the scent. Below is where the smell comes from, how to clear it step by step, and how to keep the space fresh afterward, with the full the MBur beeswax candle collection here as you read.
Why wallpaper starts to smell
Old wallpaper paste, especially traditional starch-based glue, degrades over time and smells, and if moisture gets behind the paper from humidity, a leak, or condensation, the paste and the wall can grow mold. The paper traps it against the wall.
The smell seeps out, and the paper may bubble or peel. You cannot fully fix it without dealing with what is behind the paper.
How to fix it, step by step
- Find any moisture source. Check for leaks, condensation, or humidity behind the affected wall, and fix the source, or the smell and mold return.
- Check behind the paper. Peel back a loose edge to see whether there is mold or damp on the wall and paste.
- For small musty areas, dry it out. If the paper is staying, improve ventilation, run a dehumidifier, let it dry, and wipe any accessible mold.
- For mold or degraded paste, remove the wallpaper. Strip the affected paper, remove the old paste with warm water and a scraper or a wallpaper stripper, and clean and treat any mold on the wall, then dry fully.
- Re-prime and refinish. Once dry and mold-free, prime with a mold-resistant primer and repaper or paint.
The moisture behind the paper is the real issue. Old paste alone can smell, but it is trapped damp and mold that make it strong, so fixing the water source comes first.
Keep it from coming back
Keep indoor humidity down, fix leaks, and ventilate rooms with wallpaper.
Address bubbling or peeling early, before damp and mold spread behind the paper.
Freshen the whole room once the source is gone
With the degrading paste handled, the air itself is the last step. A clean candle is the finishing touch here, best lit once the space is already clean. From there it is the fastest way to make the room read fresh rather than merely neutral.
For your home, Slice of Life fits well. It is green and garden-fresh, with tomato leaf, basil, and lemon peel, and like every MBur candle it is poured from 100% beeswax with a wooden wick and phthalate-free non-toxic fragrance oils, so freshening the air never means adding soot on top.
Frequently asked questions
Why do my wallpapered walls smell musty?
Old paste breaking down, often with damp and mold behind the paper. Find and fix the moisture, and remove the wallpaper if there is mold or degraded paste.
Can I just paint over smelly wallpaper?
Not reliably. If there is damp or mold behind it, the smell continues. Address the moisture and remove affected paper first.
How do I remove old wallpaper paste?
Soften it with warm water and a scraper, or use a wallpaper stripper, then clean the wall and let it dry fully before refinishing.
How do I know if there is mold behind the wallpaper?
A strong musty smell, bubbling or peeling paper, or discoloration are signs. Peeling back a loose edge lets you check.
Ready to keep your space smelling clean once the source is handled? Explore the MBur beeswax candle collection and find the scent that fits the room.
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