Mold on & Behind Baseboards – Causes & How to Remove

Do your baseboards look stained, swollen or cracked? Smells of damp or musty aromas in your room without visible signs of mold on walls?

You may have issues hiding behind your baseboards.

In this guide you will learn:

  • How to determine if you have mold behind your baseboards
  • What is causing the mold
  • How to prevent and remove mold issues

Mold behind baseboards is very common, especially in damp areas such as bathrooms, utility spaces and areas prone to moisture in the air.

To deal with this issue correctly you’ll need to determine where the moisture is coming from, which could be a number of problems with the fabric of your building

Signs of Mold Growth On or Behind Baseboards

Checking for visible signs and investigation is the first step in tackling your mild problem.

The main signs to be aware of with mold behind your baseboards are:

  • Bubbling or cracking of the paint on your baseboards
  • Water stain marks on the walls at low level or on the baseboards
  • Mold on carpets around edges of the room
  • Wooden flooring that lifts at edges or appears swollen
  • Mold on the front face of baseboards
  • Smells of damp without an obvious source at first

As the mold can remain hidden for some time behind your baseboards keeping a lookout for these other signs is essential in the identification of a problem.

Since there are many types of mold that can occur you should be on the lookout for brown mold on baseboards, yellow mold on baseboards or orange mold on baseboards.

It is not uncommon to have a case where multiple colors of mold are present throughout your property.

When seeking professional help and a mold survey it will be useful to highlight the problematic areas you are aware of so it’s good to do an initial inspection yourself.

Most Common Causes of Mold On Baseboards

Bathrooms and areas where moisture can be present on a regular basis are the most common spaces where mold can be on or behind baseboards.

These rooms are more susceptible due to moisture condensation on the walls or ceiling which like to travel downwards.

Dripping down onto the wooden baseboards or getting behind them through cracks and small openings.

Also wet floors, pooling of water and repeated splashing in these spaces will contribute to the likelihood of mold or mildew causing issues with your baseboards.

Since wood or MDF are absorbent materials they will soak up the moisture like a sponge.

As with all mold growth, it will require the three main ingredients:

  • Moisture
  • Food source
  • Ambient temperature

Common causes of mold will be plumbing faults in the room or apartment, these leaks could be in the ceiling void, under the floor or even inside the wall where pipes have been run.

Mopping floors, letting water remain on the edges of the floor for prolonged periods or spilling water and not drying up properly can contribute to the dampness of teh baseboards.

Wet laundry, especially if stacked on the floor or up against the baseboards can impact the

Damage to the exterior walls and cracked render can allow water to ingress and cause problems internally, as it will seep through and become trapped.

Windows or doors also present as a problematic area which can lead to mold issues, since condensation likes to collect on glass internally.

This can then run down the windows and into gaps between teh wall and window boards, being absorbed by the drywall on the internal aspects of the window reveals.

Roof problems could lead to moisture being able to travel down the walls, internally, externally or within the void itself.  This will enable moisture to become trapped and could lead to mold growth.

Blocked or faulty guttering can contribute to this problem as water runs down your walls instead of the downpipes, cracks and defects in exterior render will permit it entry to places it shouldn’t be.

Cracked glass on your glazing units can also lead to more condensation than usual internally during colder months.

Curtains or soft furnishings touching the glass, when it condensates will collect some moisture, adding to the overall residual damp in the room if not fully dried out. Heavyweight fabrics or large sections which are folded once opened can be particularly troublesome.

Not only does the mold affect the appearance of soft furnishing it can lead to staining and deterioration of fabrics.

How Do I Check for Mold Behind Baseboards?

Your first inspections should be visual, which will highlight any potential issues on the surface or discovery of telltale signs already mentioned, such as staining or damages.

To properly check behind baseboards you will need to remove them.

This will create damage to your home, and will usually require the baseboards to be replaced.

Damage to the drywall and adjoining baseboards is also likely depending on how they’ve been installed, will dictate teh severity.

You should be prepared to undertake some repairs and redecoration or have someone that can assist with this.

Is it normal to find mold behind baseboard?

It is common but is not normal, as this small void tends to be a trap for moisture and is dark.

Food for the mold can become trapped down here and provide a continual food source assisting the growth of the microorganisms.

Gaps in the caulk where the baseboard and wall meet allow particles and debris to enter and become trapped.

For older buildings, it will be even more prevalent as they are prone to more moisture retention in building materials used.

Walls that aren’t flat or level can result in larger gaps between baseboards and walls, over time caulk will sink, split or deteriorate.

So not only is it useful from an aesthetical standpoint and tidies up the join lines it is also functional.

Should the gaps be large enough you might be able to shine a torch into the void and investigate mold growth.

How long does it take for mold to grow behind baseboard?

The rate of growth is heavily dependant on the factors which set up the environment for mold to flourish.

Typically it will have been an underlying issue for months or years.

However, it can colonise and spread rapidly given The right environment, on a damp baseboard the initial mold can get started in as little as 48 hours and begin its rapid growth.

As the spores become mobilised in teh air they will settle on other surfaces that provide a food source, given teh correct conditions for growth t

To put this into perspective if you took a  vacation and your home encountered a problem whilst aways such as a leak, you could arrive home after to a week or two to discover an almost unrecognisable space.

How to Clean & Get Rid of Mold from Baseboards

Taking care of superficial, visible mold on your baseboards is usually the easy part.

A simple clean down with a mold cleaning or inhibiting spray or fungicidal solution will usually take care of it.

Be sure to dry the areas after cleaning has taken place.

Should the problem be more serious then surface mold will return, this could mean issues hidden behind your baseboards.

Why are my baseboards turning black?

They will do so if mold has been given the opportunity to flourish on or behind them.

Black mold is a particular type, Stachybotrys Chartarum or Stachybotrys atra, which has a reputation for causing health issues.

This could also affect pets you have along with your family so needs to be addressed and dealt with correctly.

By your baseboards turning black it means they have acquired an issue with black mold or have become extremely dirty, make an assessment or seek professional input.

Cleaning mold or mildew behind your baseboards

Once you have removed the boards it is important to expose the extent of the mold problem.

Clean the area with a scrubbing brush and suitable mold inhibitor, flowing the instructions for a specific brand that you find at the local market or hardware store.

Always wear suitable protective equipment when doing so and be careful to ventilate areas and dry the wall space, flooring and other surfaces thoroughly afterwards.

Do not attempt to refit new baseboards unless the cause of teh problem has been dealt with and space has been thoroughly cleaned.

A dehumidifier or a negative air machine with a HEPA filter can be very useful here.

Preventing Mold On your Baseboards

Once the root cause of these issues has been dealt with, no doubt you’ll want to prevent it from happening again, here’s how we recommend doing so:

General considerations

Aim to keep the space clean and clear of clutter, especially items against teh wall or baseboards.

Cooler temperatures will inhibit mold growth

Well ventilated areas will not give moisture teh chance to build up

Mold inhibiting paints prevent it from colonising, particularly useful in rooms such as basements or bathrooms

Preventing mold on baseboards in your bathroom

Taking some simple steps each time you use the room will help.

In particular ventilation, which can be achieved by having a sufficiently rated extractor fan fitted.

Opening a window can prove to be useful. especially in the instance of not having an extractor fan but in colder climates can be somewhat impractical.

Drying floors and the edge where the flooring meets the baseboard is particularly important.

A bead of silicone can prove o be helpful in preventing water ingress underneath the baseboards and sealing the area.

Preventing mold on baseboards in closet

Regular inspections are vital here in identifying potential issues that may have arisen.

Good ventilation is key, open the door often.

Remove any items that retain moisture easily and don’t store damp clothing, sweaty gym kit or footwear that is wet.

A dehumidifier can be helpful but may not be feasible due to size.

Preventing mold on baseboards in bedroom

Keep furniture away from problematic areas, especially large items such as wardrobes or sideboards.

Blocking the view of the walls and baseboards can mean that mold or potential issues can go unnoticed for longer.

House plants kept in close proximity to the walls, especially external walls can be problematic so we advise not doing so.  When watering and caring for your plants be vigilant not to wet the area and monitor the wall and floor for signs or damp issues.

Are there Mold Resistant Baseboards?

For those of you who seek an alternative material for your baseboards, especially helpful if you’ve had mold behind baseboards in the basement or other problematic areas, there is a solution.

Usually, the baseboards will be made from wood or MDF, however, you can buy plastic Polyurethane versions.

These will come in the most common moulding profiles so shouldn’t be too tricky to find an exact or close match to the rest of your home.

Once installed they can be painted just like any other baseboard, you’ll need to find a suitable primer or basecoat to do so.

Due to them being manufactured from plastic there is no moisture retention or degradation due to mold or mildew on baseboards.

They’re also durable, waterproof and more resistant to damage.

Should there have been problems with damp or behind the baseboards previously or issues with your walls then naturally they will need addressing before you install new baseboards otherwise the issues will persist.

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