5 red flags to look for when choosing a new home, according to a professional cleaner

• Lina DaSilva has more than 10 years of experience in residential cleaning.
• She shared five red flags for people to look out for when moving into a new property.

This as-told-to essay is based on a conversation with Lina DaSilva, the 32-year-old founder of the residential-cleaning company Toronto Shine Cleaning. The following has been edited for length and clarity.

There's something invigorating about the promise of a new place, but not all that glitters is gold — or clean, for that matter.

Failing to see red flags when you're viewing a property to buy or rent might set you up for financial, mental, and physical stress.

During my time as a residential cleaner, and now the owner of a residential-cleaning company, handling move-in and move-out cleanings has been a significant part of my job for over a decade.

I've seen the worst of the worst of house issues and learned red flags that I could never ignore when moving into a property.

Water damage and mold

The first and most common red flags are water damage and mold.

This is a big issue not only because of the obvious health implications, especially if you have asthma, but also because it can bring a lot of financial issues down the line, such as damage to clothing and electronics.

Most of our clients with these issues have to do a full inspection of the house to find the extent of the damage. If you don't deal with evidence of mold or water damage head-on, a small leak can quickly turn into a flooded room or damp wall. Water can also cause structural problems.

Mold mostly shows as black specks on surfaces but sometimes appears as white stains if it has been bleached. Common areas you should look at are under the sink, behind the bathtub, and inside the closets.

As for water damage, this can look like cracked and bubbling walls or uneven floorboards.

You should check the bathroom, the laundry room, and the basement for signs of water damage.

These areas can be dark, so I recommend bringing a pocket torch to house viewings to check these corners.

Stained carpets

Stained carpets aren't just an aesthetic problem — they could signal a deeper issue such as a pest infestation or water damage.

If the carpet stains are inconsistent colors, they could be from water damage. Under-the-floor water damage would show on a yellow carpet as red and brown patches and the carpet would be humid.

If there is a pest issue, you may see small red stains, which can be a sign of bedbugs.

Any evidence of pests can result in mental stress as well as financial anxiety. If you have pests in your house, you're going to be freaking out all the time thinking, "Where are they?" If you notice any evidence of pests on a property, ask for a full inspection and fumigation before agreeing to move in.

Cracked or missing caulk

Caulk is the waterproof sealant that goes around windows and bathtubs. If it's missing, it could cause serious issues and is often an overlooked red flag.

Broken or missing caulk around the windows means heat will easily get out and drive up energy bills. If it's broken around the bath, you risk water damage.

When I bought my home, I noticed there was no caulk around the bathtub. My husband told the property owner that we would move in only after that issue was resolved. The guy was very nice and fixed the issue.

Dealing with repairs once you've settled in is a hassle. We wouldn't have been able to use the bath without worsening the risk of leaks and damage.

Bad smells

If you have a musty smell in the house, it could be a sign of a deeper problem. Again, it could be water damage, pests, or a sign of something worse.

My company was once asked to clean a property by a lady who was trying to sell her house after her husband died in it. I'm not sure how long the body was there, but the house was full of flies and dead worms, and the smell of decay was deep in the house's structure.

The flooring and furniture had to be replaced before we could clean the property. I'm no expert in real estate, but something like that usually affects how people perceive the property.

Nobody is going to tell you why a property smells, but you have the right to know. So if you smell something, ask for a full report on where it's coming from.

Denying a full inspection

My final red flag is if the real-estate agents deny you a full property inspection. Always go see a property for yourself and check every room and space.

If they're trying to hide something, it's probably very serious.

In this case, I'd simply walk away. It's not worth living somewhere you haven't checked out yourself.

Leverage problems to negotiate a better deal

Red flags such as stained carpets or unseemly smells could be leveraged to negotiate a lower rent or purchase price.

However, if the red flag is more serious — such as water damage, mold, or denial of inspection — you should prioritize your safety and the property's livability, rather than attempt to get a lower price.