Whether you just installed a new floor or moved into a new place, you might notice a gap between the tile flooring and the wall. It’s not a good idea to leave that void as is. Let’s find out why there’s a space in the first place and learn how to fill the gap between a baseboard and tile floor.

What’s the Gap, Anyway?

Experts in the industry recommend that you leave a ¼-inch gap around the perimeter of a tile floor when installing it. This allows for shifting without causing the tiles to crack. 

You should fill this gap at the time of installation to prevent problems in the future. But the gap may widen as the house settles. Movement in the walls and joists can throw the junction of the tiles and wall out of square.  Therefore, over time, you might have to fill the gap between baseboard and tile floor. 

Why Should You Fill the Gap Between Baseboard and Tile Floor?

If the gap is so small that you barely notice it, why should you fill it? The empty space attracts moisture, dirt and organic debris. As this builds up in the dark space, it can develop mold and fungal growth. Gaps between the tile and baseboard act as traps for bacteria. They can also contribute to pest problems. 

It’s best to seal any gaps in your tile as soon as you notice them. If the gaps are caused by broken tiles, have them repaired or replaced. Otherwise, moisture can continue to build up in the empty spaces and damage your subfloor.

When this area is left unsealed, it reduces the insulative qualities of your flooring. You might find that your flooring feels extra cool to the touch or your electric bill is costlier than it should be.

Should You Use Caulk or Grout in the Gap?

Many tile floors require grout between the panels. But you don’t need to extend the grout around the edges. Grout is porous, which means that it doesn’t have waterproofing capabilities. If it absorbs water, it can trap that moisture close to your drywall, creating the perfect environment for mold. Grout around the edges of the floor is also prone to cracking.

Instead of using grout to fill the gap between a baseboard and tile floor, opt for caulk. It’s flexible and waterproof, creating a strong seal around the perimeter of your room. Latex painter’s caulk is ideal for this project. It creates a secure, flexible bond and accepts paint without flaking.

You might want to avoid acrylic caulk, especially in wet areas such as bathrooms. Although acrylic caulk  doesn’t attract lint and dust, it’s also not waterproof. Silicone caulk is completely waterproof and very flexible. However, it doesn’t take paint very well and isn’t recommended for wooden areas, such as baseboards.

How to Fill a ¼-Inch Gap Between Baseboard and Tile Floor

As long as the gap between the baseboard and the tile floor is narrower than ¼ inches, you can seal it using caulk alone. Here are the steps for how to fill a ¼-inch gap between a baseboard and tile floor:

  • Use a small brush to remove debris from the gap.
  • Vacuum the space using a crevice attachment.
  • Use a damp sponge to scrub away any remaining residue.
  • Dry the area thoroughly with a towel.
  • Apply painter’s tape along the tile next to the gap so that you don’t get caulk on the grout or tile.
  • Cut the tip off of the caulk tube or gun, leaving an ⅛-inch opening.
  • Using a smooth, steady motion, apply a narrow strand of caulk along the gap.
  • Smooth the caulk between the baseboard and the tile with a tool or your finger.
  • After the caulk has dried and cured completely, paint the baseboard and the caulk. Use painter’s tape where appropriate to create a clean line.

How to Fill a ½-Inch Gap Between Baseboard and Tile Floor

If the gap between the baseboard and tile floor is larger than ¼ inches, you can’t use caulk alone. The caulk would shrink as it dried, creating a messy look and pulling away from the edges. This would impair the seal and negate the purpose of filling the gap in the first place. 

Adding shoe molding fills in part of the gap, leaving a space that’s ¼ inches or smaller to finish off with caulk. Shoe molding is usually narrower than quarter-round molding. However, you may need to use quarter-round molding if the gap is extremely wide.

By adding shoe molding, you can also customize the architectural appearance of your flooring. This molding comes in a variety of profiles, from sleek rectangular edges to stepped curves. 

It makes sense to use wooden shoe molding in most homes. But you can add strips of flexible shoe molding in large or commercial settings for ease of installation and cleaning. 

You can also find self-adhesive shoe molding that looks a lot like wood to get the job done faster. This might also be the best option in high-humidity environments because it doesn’t swell and shrink as much as wood. Just make sure that you can paint it to match the baseboards to tie everything together.

After installing shoe molding, you can follow the instructions above for how to fill the gap between a baseboard and tile floor.

Tips for How to Fill the Gap Between Baseboard and Tile Floor

Filling the space meticulously will help your floor look great for a long time. Doing this reduces the risk of damage and improves the aesthetics of your home. The following tips will help you get the best results when filling the gap between a baseboard and tile floor:

  • Measure the tile carefully.
  • Remove baseboards when replacing or installing flooring for the most attractive results.
  • Use a new drop cloth over the tile so that it doesn’t get damaged by the caulk.
  • Use a paintable caulk so that you can create a seamless finish from the edge of the tile to the wall.
  • Painting the caulk also reduces its stickiness and ability to attract dirt and dust.
  • You’ll need about one tube of caulk to fill a ¼-inch gap in an average-sized bathroom.
  • Dip your finger in alcohol before using it to smooth the bead of caulk.
  • Remove the painter’s tape before the caulk dries to avoid trapping it beneath the latex.
  • Clean caulk spills, splatters or drips with a damp rag as soon as they happen.
  • Remove dried caulk from unwanted surfaces using a sharp razor blade, taking care not to scratch the tile.
  • If wielding a caulking gun doesn’t feel natural, use a small tube of caulk for better control.
  • For a modern, consistent, luxurious look in a bathroom, consider using pieces of tile as trim instead of wooden baseboards.
  • If you feel air flowing near the gap, consider adding weather stripping for extra insulation.

Don’t be tempted to leave the gap between the baseboard and tile floor unsealed just because it’s narrow. Even a small space can attract critters, soil and moisture. Caulking the gap is easy to do yourself. If you’re not sure how to do it, contact a flooring professional or general contractor for help.