Skip to Content

Should There Be a Gap Between Baseboard and Floor

Apart from having a negative impact on the overall appearance of a room, gaps between baseboards and the floor could be a source of heat loss and might serve as an ideal living space for insects. Gaps occur due to a variety of reasons. These may be minor issues, like a badly cut baseboard, or worse, it could be the result of serious structural problems.  

In this article, I explain the major causes of the gaps between your floor and baseboard, how to tell if it is due to structural defects, and how you can cover these gaps. 

Baseboard gaps aren’t functional, i.e., they shouldn’t be there. But they are common and may not indicate anything more serious than uneven floors or carpet removal. There are cases where gaps aren’t normal. Poorly built floors that sag or slope and unevenly cut or installed baseboards can create a gap.

Gap Is Probably Normal

Putting skirting board to a fresh paint wall baseboard and floor

For the most part, gaps between the baseboards and the floor are normal. I wouldn’t say that you should have gaps, i.e., they are not functional, but they are not necessarily a sign of serious defects.

They may indicate slight imperfections in the way that the house has been built or how they have been altered or how they have moved and settled with age, but even these are nothing you should lose sleep over.

Floors Are Not Always Even

Uneven floors are a common occurrence in many homes, especially older buildings.

A popular misconception is that it is always due to structural damage. However, there are non-structural factors that can affect the evenness of a floor and some of them include:

  • The flooring material.
  • The type of subflooring used.
  • The architectural layout of the building. 

Apart from these factors, the age of a building plays a huge role in the floor’s evenness. Changes in soil conditions often cause foundations to shift over time, resulting in movement of the floor and ceiling.

If the movement causes the floor to sink, a gap might appear between the baseboard and floor because the board is attached to a particular spot on the wall and cannot move to accommodate the changes in the floor level.

May Indicate Carpet Was Once Installed

If you recently moved into an apartment and notice gaps between the baseboards and floor, then it could be a clear indication that a carpet used to be in place. This is especially true if the gaps have a consistent dimension.

For a clean finish, carpets are usually tucked underneath baseboards. So, if the carpet is eventually removed, they’d be a gap where it used to be. 

If the baseboard is installed before the carpet, it is common practice to leave a gap to match the size of the carpet you intend to install before attaching the baseboard.

The size of this type of gap would depend on the thickness of the carpet that was installed. The thicker the carpet’s padding, the wider the opening.  

Gap Can Indicate Problem or Poor Design

While gaps in between floor and baseboard are, for the most part normal, they can sometimes indicate structural defects. They could also result from poor craftsmanship on the part of the contractor responsible for building the floor. 

Mans hands putting white baseboard, do it yourself

Sagging Floor

Sagging floors are not always perceptible. The floor might be sloping, signifying serious issues, or it could sink only in certain parts of the room. 

If the floor sags around the wall, the baseboard would most likely disjoint from the floor, resulting in a gap.  

The major causes of sagging floors include:

  • Water damage: This could be because of leaky pipes, poor drainage, or inadequate protection against groundwater. If left unattended, it would damage joists and subflooring, especially those made with wood. 
  • Poorly constructed subflooring: If the subflooring is constructed with inferior materials, it would buckle in no time. Also, if the joists are not fitted correctly, it could cause the floor to be uneven. 
  • Foundational movement: This could result from soil movement, badly built foundation, or water damage. 
  • Foundation settling and joists sagging with age

Badly Cut Baseboard

The gap might be because the baseboard itself is uneven. This can happen if it is badly cut such that some parts are wider than others or if there are indentations along the length of the wood. 

If this happens, when the baseboard is installed on the wall, there would be gaps to match the irregularities in the wood. The size of the gap might vary from one point to the other, depending on the cut of the wood. 

If the gap between your floor and baseboard is due to a badly cut baseboard then you’re in luck because you can fix the fault without worrying about underlying structural issues that might cause the gap to reappear or worse, threaten the structural integrity of your home. 

Good or Bad Gap: How to Tell? 

Sometimes gaps are harmless aesthetic flaws that can easily be covered and other times they could be a sign of structural issues. The key is knowing how to tell if your gap is innocuous or sinister.

If the gap is due to a previously installed carpet, you will notice that the openings have a defined proportion, and even if there are disparities in the size of the gap, it would be minute. You may also notice marks on the floor under the baseboard where the carpet had been secured.

Gaps that are caused by badly cut or ineptly installed baseboards are easy to spot. You’d have to take a close look at your baseboard and, if you notice irregularities in the board wherever there is a gap, then the problem is most likely from your baseboard. 

You can also bring out the measuring tape and measure the width of the board at intervals to see if they match.

To determine if the opening is due to a sagging floor, examine the floor for recessed areas. You can expand your inspection a couple of feet away from the gap so that you’d notice if there is a slope in the flooring or if the floor is uneven in other areas as well. Get a marble and see how it rolls on the floor. 

Most time, gaps that are caused by structural issues are accompanied by cracks in the floor and walls.

A common sign of warped subflooring is that your floor would make squeaky sounds whenever you walk across it. If you experience this, then your floor joists might need a repair or replacement.  

Sealing Baseboards is Quite Easy

Often, the gap is not only an eyesore but also a source of drafts during cold spells.

The most common fix for stopping the drafts you feel coming from the baseboards is simply to caulk over any gaps or cracks around your baseboards.

Caulking over the gaps is a rather easy job, even for beginners. Additionally, using a latex-based caulk will allow you to paint over the caulk if necessary to ensure that your room aesthetic is not impaired by this practical repair. 

Dap 18128 Alex Plus Acrylic Latex Caulk Plus Silicone 5.5-Ounce

There are two things I’d like to point out with caulking. One is that, when used alone, it is only really a fix for smaller cracks, but it is valuable for larger cracks when used in conjunction with another method. The second is that it can sometimes be a messy job.

Preventing Mess

When you’re looking to fill the top edge of your baseboard, you can apply painter’s tape onto your wall before caulking. Leave a sliver of space between the gap and the tape’s edge to give the caulk room to taper off cleanly.

While caulking, the top gap of your baseboard will be the same regardless of what kind of flooring you have. Caulking the bottom edge of your baseboard is a different story.

With hardwood or tile flooring, you can apply tape to the floor along the edge of your baseboards, just like you would apply tape to the wall when filling the top gap.

For a carpeted floor, you can caulk the top of the baseboard, but you shouldn’t normally need to do anything to the bottom of your baseboard. Baseboards and carpets are generally installed so that there is no gap (any natural gap that exists as a result of slight unevenness of the flooring is filled by the carpet’s edge).

Of course, that might night be the case for you. If the space between your carpet and the bottom of your baseboards is very large, you should use a different method instead of or in combination with caulk to fill the gap.

Tools and Products

Before you begin, you will need to make sure you have all the necessary materials.

ToolAmazon link
Utility knifeView
Latex-based (or primarily latex-based) caulkView
Caulking gunView
Caulk finished tool (you can also just use a plastic spoon or even your finger. But the tool is less messy)View
Rag (onto which you can wipe the excess caulk)
Painter’s tapeView

How to Caulk

Clean the baseboard of dirt and, with the utility knife, remove the previous caulking.

Using the gun, apply caulk along the edge of your baseboards. After filling each section, you will want to run your caulk finishing tool or wet finger over the strip you just caulked before it becomes too stiff. This will push the caulk into any small holes that were missed and smooth out the bead. 

If you are a visual learner, this video will help you learn to caulk.

Seal Larger Cracks With Spray Foam Insulation

If you have a wider gap along your baseboards, just using caulk may not be enough. In this case, you might choose to use spray foam insulation.

There are two types of spray foam—high expansion and low expansion foam. 

Unless you are experienced with using spray foam insulation, it can also be hard to gauge just how much the foam will expand after application. Because a baseboard gap is a relatively small area, it may be best to use a low expansion foam to avoid overexpansion.

Spray foam is cheap and easy to get the hang of, but it can be messy, much messier than caulk.

In addition, the foam can even be harmful if you don’t provide ample ventilation to the area you will be working in. This is because spray foam insulation releases gas compounds that can be harmful to the body.

Preventing Mess

As with caulk, you can tape off the areas you don’t want to get messy with foam. However, you’ll want to place the tape flush with the gap instead of leaving a small space. This leaves room for the caulk to lie over the foam, creating a better seal.

If you have flat flooring, like wood or tile, taping is easy to do. But if you have a carpeted floor, you will need to be extremely careful and use plenty of tape and newspaper to protect your flooring. It is difficult to get the foam off of any surface, but it is particularly tricky with fabric or carpeting. 

YOPAY 6 Pack Tape Caulk Strip, 1.5 Inch Wide PVC Waterproof Self Adhesive Tape for Bathtub Bathroom Shower Toilet Kitchen and Wall Sealing Protector, White

You may even want to look into peeling up the edges of your carpet before using foam, then replacing them once it has cured.

It’s also not a bad idea to test the spray foam outside on a sheet of paper to get the hang of controlling the flow before using it indoors.

Tools and Products

Luckily, there aren’t many materials needed for using spray foam insulation.

ToolAmazon link
Spray foamView
Rag to clean off spray nozzle and other messes
Utility knife to cut through any foam that expands too farView
OR putty knifeView
Painter’s tapeView

How to Apply Spray Foam

As mentioned, spray foam is very easy to use. Once you have properly protected your working area, you’ll want to insert the straw of your spray foam can into the gap and gently squeeze the trigger to fill the space.

Seal Spray Foam High Performance Closed Cell Insulating Foam Can Kit w/Gun Foam Applicator and 1 Can of Cleaner (150 Board FT-6 Cans)

Remember to allow the foam some space to expand, as it is easier to apply more foam if needed than it is to remove excess.

After the foam has been applied and allowed enough time to dry, you can caulk over the foam to provide an extra seal and give your baseboards a professional, finished appearance.

If you peeled back the carpet to access the gap, you would replace it after everything has cured.

Install Foam Backer Rod Behind Baseboard

If you have very large gaps below the baseboard, or if you simply prefer to avoid the mess of spray foam, you may opt to place a foam rod behind your baseboards instead.

If your home’s walls and/or flooring are primarily constructed with wood, using a foam backer rod may actually be in your best interest because wood expands and contracts with changes in weather. So, using a foam rod instead of a more permanent sealant gives your home freedom to “move.” 

If your home’s walls and/or flooring are primarily constructed with wood, using a foam backer rod may actually be in your best interest.

Foam backer rods are far less messy than spray foams, and they are both easy to install and easy to remove.

However, they are also very easy to compress. This is good in theory because you can stuff the rods into spaces that are much smaller than their diameter, but this can also make it difficult to figure out your sizing.

A good rule of thumb is to pick a rod size that is just slightly wider than the gap you wish to seal, but no larger than twice the diameter of the gap.

Tools and Products

Because foam backer rods are so easy to install, there are no real precautionary measures needed to prevent mess. For this reason, we’ll jump straight to the materials you’ll need for the job, which is very simple:

  1. Correctly sized foam backer rods.
  2. A putty knife (or another thin, solid tool).
  3. A utility knife to cut the foam.

How to Install the Foam Backer Rods

To install the foam rods in the gaps under your baseboards, make sure the area is clean first.

Remove old caulk if there is any, then simply cut your rods to length and shove them snugly into the gap under your baseboards using your putty knife or similar tool.

For solid flooring, you can now caulk over the gap.

For carpet, you may want to consider a few different options.

  • If you peeled back your carpet to access the gap, you can now caulk over the foam and put the carpet back into place once it dries.
  • If you did not peel back the carpet, the gap might not be so big that it is easily noticed, and you may choose to leave it without caulking it now that it is more airtight.
  • However, if the gap is clearly visible, you may choose to disguise the space by attaching a matching shoe molding or quarter round to the bottom of the baseboard above the edge of the carpet. If this is the route you choose, you will want to caulk the top gap, where the shoe molding meets your baseboard, to give it a finished look.


Amazon and the Amazon logo are trademarks of, Inc, or its affiliates.