Can You Sleep in An Unfinished Basement? (7 Risks)


This article has been compiled, researched, and medically reviewed by Stephanie Abi Zeid (Embryologist, Andrologist, B.S, MSc) for factual accuracy.

Many people plan to live or sleep in a basement for reasons related to cost, tenancy, or for enlarging their living space, but can you sleep safely in an unfinished basement or not?

Sleeping in an unfinished basement is NOT safe long-term due to the risk of allergic reactions, lung cancer, carbon monoxide poisoning, breathing difficulties, and death via fires or floods. However, it’s possible to sleep in an unfinished basement for a night or two if proper precautions are taken.

The rest of this article explains in more detail the risks of sleeping in an unfinished basement and reveals some adjustments that can allow you to sleep in the basement relatively safely in the short term.

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The 7 Risks of Sleeping in An Unfinished Basement

 The 7 major risks of sleeping in an unfinished basement are as follows:

1: Allergic Reactions to Mold Spores

A basement is dark and damp; which can cause moisture and encourage the growth of mold – resulting in the release of mold spores, which travel through the air.

Being exposed to mold spores can result in allergic reactions, the worsening of asthma, skin irritation, and respiratory issues – especially in smokers and those with pre-existing allergies [1].

The symptoms can range from a runny nose, watery eyes, coughing, and sneezing to more intense problems like difficulty breathing and chest pain. 

2: Lung Cancer Caused by Radon Gas 

Basements can contain high levels of radon – a colorless and odorless gas that is formed by the natural radioactive decay of ammonium.

Radon gases typically seep through cracks in walls and floors, gaps around pipes, floor drains, or any other gap that contacts with soil. 

If the cracks are not sealed properly, radon gases can act as a carcinogen – potentially leading to lung cancer and respiratory diseases; especially during long-term exposure [2].   

3: Carbon Monoxide Poisoning

If your fuel-fired furnace is located in your basement, there’s a risk that carbon monoxide might settle in the basement where it can cause health issues.

Carbon monoxide is not detectable by smell and is usually unnoticed until you experience symptoms like headache, dizziness, and loss of cognitive abilities.

Exposure to carbon monoxide gas can lead to death [3]. 

4: Health Issues Caused by Sewer Gas

Basements usually contain floor drains that are connected to plumbing traps.

Plumbing traps are designed to block gases for hygienic purposes.

However, these traps can dry out – especially when not frequently used.

This can allow sewer gases like hydrogen sulfide, ammonia, and methane to flow into your basement and potentially cause fatigue, headaches, nausea, dizziness, and poor memory when the level of exposure is low [4].

Exposure to higher levels of sewer gas in your home are rare, but can cause more serious issues like lung irritation and seizures.

5: Breathing Difficulties Due to Lack of Ventilation

Because basements are below the ground level of your house, you can often smell a musty odor due to the lack of proper ventilation and natural light.

This absence of fresh air can result in breathing difficulties, asthma attacks, and other respiratory problems – especially for people with pre-existing respiratory medical conditions that spend lots of time in the basement. 

6: Health Issues Caused by VOCs

Basements are often used as utility rooms that store leftover cans of varnishes, solvents, and paint.

The fumes from these items can be harmful due to the VOCs they emit, which can lead to allergies, respiratory and breathing problems, and damage to the brain and other organs.

Long-term exposure to some VOCs can cause cancer [5]. 

7: Death Due to Fire or Floods

Basements are located below street level and are often used to store heat-generating equipment like water heaters, dryers, and HVAC units.

So the risk of fire and flood is higher in such an environment.

And because basements have limited ventilation and lack emergency exits, this could lead to death due to the inability to escape a fire or a flood. 

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6 Ways to Sleep in a Basement Safely (Short Term)

If you have no other choice but to sleep in the basement you can do this relatively safely in the short-term if you clean the basement, test for harmful gasses, have proper lighting, ensure proper ventilation, remove items that emit VOCs, take steps to reduce the risk of fire, and have an escape route if a fire does occur.

More details below: 

1: Clean the Basement

Molds, dust mites, pests, and rodents can proliferate in a basement – especially on surfaces where moisture builds up. 

Use detergents and cleansers to get rid of these allergens, irritants, and unwanted creatures.

You can use white vinegar on the walls, floors, and ceilings of the basement because vinegar can get into porous surfaces to kill many types of mold. 

Use a dehumidifier and seal the cracks in the foundation in order to reduce dampness and therefore prevent future occurrence of mildew in the basement. 

Chemical treatments and poisons against bugs and termites may be toxic, so it would be best to hire a qualified inspector to detect infestations and suggest a more efficient and healthy treatment to sleep safely in the basement.   

2: Test for the Presence of Gases

Dangerous gases like radon and carbon monoxide cannot be detected with human senses because they are colorless, odorless, and tasteless.  

Therefore, use carbon monoxide detectors to prevent carbon monoxide poisoning and have your gas or oil-fueled furnace inspected by a qualified technician every year to ensure that it is in proper functioning mode.   

Use a radon testing kit or install a radon detector that will indicate when radon gas levels become too high in the basement.

Hire a radon remediation professional to mitigate the risks.   

Furthermore, to mitigate the risks of sewage fumes, flush your basement’s floor drains with water regularly. 

3: Install Proper Lighting 

Basements are usually dark due to the lack of windows – which can attract bugs and rodents.

In such a case, you should incorporate fluorescent, incandescent, or halogen lighting to make the basement less attractive to these unwanted pests.

Paint the walls with neutral colors because they are easy on the eyes and can brighten up the basement to make you sleep comfortably at night. 

4: Ensure Proper Ventilation

Proper ventilation is vital in basements to prevent a stuffy smell, dampness, and other health hazards. 

Add fans to increase ventilation, or install more windows to let fresh air in to your basement. 

Furthermore, you can connect your basement to your home’s HVAC (heating, ventilation, and air conditioning) system to make sure it is properly ventilated. 

A dehumidifier and an air purifier that uses HEPA and carbon filters are also suitable for basements to capture pollutants, unpleasant odors, and gases.  

5: Minimize the Effects of VOCs

Avoid storing paints and other items that give off VOCs in your basement.

If this isn’t possible, buy low or non-VOC products to minimize your exposure to toxins. 

Make sure you seal all your leftover cans of paint that are stored in the basement and discard cans that have leaked. 

Don’t forget to ventilate the space regularly to minimize the effects of off-gassing in the air. 

6: Introduce Fire Safety 

Make sure you take all precautions needed to stay safe in the event of a fire. 

Set up a smoke alarm and a carbon monoxide detector in the basement to be alerted in case a fire occurs. 

Make sure that doors are not blocked and that you are able to escape safely through an emergency exit. 

Regularly check your electrical appliances to make sure they are in good condition and function properly to avoid any risk of fire. 

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Avoid Sleeping in the Basement

Sleeping in an unfinished basement can harm your health and lead to respiratory problems and cancer due to the lack of natural light and air, and exposure to harmful things like radon gas, molds, dust, and chemicals. 

Therefore, it’s advised that you do not sleep in an unfinished basement as a rule.

However, if you have no other choice, then you can sleep in a basement relatively safely for a night or two if you take some precautions such as cleaning the space thoroughly and taking steps to guard against fire and carbon monoxide poisoning.

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Sources and References

[1] Targonski, Paul. Effect of environmental molds on risk of death from asthma during the pollen season. vol. 95, 1995. Science Direct, Accessed 26 December 2020.

[2] Xie, Dong. Influence of environmental factors on indoor radon concentration levels in the basement and ground floor of a building – A case study. vol. 82, 2015. Science Direct, Accessed 26 December 2020.

[3] Ernst, Armin. “Carbon Monoxide Poisoning.” The New England Journal Of Medicine, vol. 339, 1998, pp. 1603-1608. NEJM, Accessed 26 December 2020.

[4] ‘What You Need to Know if You Smell Sewer Gas’. Healthline. Accessed 26 December 2020.

[5] ‘Volatile Organic Compounds’. American Lung Association. Accessed 26 December 2020.

Image Attribution and Licencing

Main image: ‘Interior Room With Concrete Walls and Stairs’ by Shenki (Getty Images Pro) – used with permission under the terms of Canva’s One Design Use License Agreement.