Fill gaps in floorboards to stop drafts and improve the floor's appearance. Use flexible acrylic gap filler (best for smaller gaps and drafts), wooden slivers/strips (best for wide, structural gaps), or a sawdust and resin mixture (ideal for matching your floor's exact color).
Before choosing your approach, observe your floor to determine whether your gaps expand or shrink. If the cavities in your floor fluctuate, then use a flexible caulking sealant. If the gaps stay the same all year round, then use a wood filler or fill them with strips of flooring.
Timeless wood colors are natural, organic hues that bridge the gap between warm and cool without relying on passing fads. The most classic choices are pale, natural wood and mid-tone browns. These choices highlight natural grain patterns and adapt easily to changing furniture and decor styles.
To fill gaps in floorboards, the best material depends on whether your wood is static or shifting. Use flexible acrylic caulk or foam strips for floors that expand and contract. For stationary gaps, use wood putty or a mix of sawdust and wood glue.
Use Caulk to Fill the Gap
You will want to line the floor with blue painter's tape to minimize cleanup. You'll want to use a paintable latex silicone caulk to fill the gap. Once the caulk is dried, paint the caulk to match the baseboards.
To fill gaps in floorboards without sanding, use a flexible, color-matched acrylic wood caulk or gap filler (like LOBA GapFiller). Simply clean out the debris, apply painter's tape to protect the boards, squeeze the filler deep into the gaps, and smooth it out with a damp finger.
Caulk is ideal for filling gaps in living areas like between skirting boards, picture rails and built-in furniture. You can paint over it with any paints or varnishes. While it's still wet, it can be easily removed with a damp cloth.
What is the Best Wood Filler For Large Gaps? We recommend Woodwise Full Trowel for medium to large gaps in flooring. This type of filler can be used on water and solvent-based stains or finishes. It can be used to fill cracks, nail holes, gouges, and any broken edges.
Wood filler is ideal for repairs on unfinished wood, as it hardens quickly and retains its durability, allowing for sanding and painting to achieve a flawless finish. On the other hand, wood putty excels at addressing minor blemishes on finished wood, but it takes quite some time to dry and doesn't harden fully.
Those in favour of leaving gaps argue that they allow the wood to breathe, giving it room to expand and contract with changes in temperature and humidity. On the other hand, some believe that gaps are simply a sign of sloppy workmanship and insist that floorboards should be laid as tightly as possible.
Dark Flooring
Dark-stained floors create a dramatic backdrop that allows furniture to stand out against the rich, velvety darkness. Additionally, the dark color absorbs and reflects light, adding depth and visual interest to the space throughout the home.
In 2026, flooring trends revolve around warmth and natural textures, with cool, flat grays officially on their way out. The most popular colors include:
Beige, taupe, and "mushroom" neutrals are officially replacing the cool, sterile grays of the last decade. Designers are leaning into warm khakis, sandy beiges, creamy whites, and earthy tones that add a cozy, comforting energy to spaces.
To caulk between your floorboards, you will need to prepare the following materials:
Wood filler does not shrink after drying like caulk. And you can shape the wood filler after it dries (over fill the joint, let it dry, then sand the angle to 90 degrees). This may be necessary here because that joint is so loose. You will see divots after dried if you use caulk.
It is crucial to avoid caulking weep holes, window trims, and movable parts. Before applying the new caulk, you should carefully remove the old caulk using the appropriate tools and techniques. Choosing the right caulk for specific applications, like interior vs. exterior use, is essential.
You can fill gaps up to 1/8". For wider gaps, it may be more aesthetically pleasing to insert a matching wood "sliver" or "dutchman" before applying the filler. This approach provides a more seamless and natural appearance.
Epoxy fillers are fantastic for filling voids as they don't shrink over time, and they are as flexible as wood. Once dried, they can be sanded for a smooth finish, painted, and even look great underwood oils and varnishes too. For us, Epoxy wood fillers are the most versatile filler on the market.
Disadvantages of Wood Putty
Wood putty is designed for cosmetic purposes and won't add to the structural integrity of your project. It's also prone to shrinking and cracking if applied too thick. Wood putty is slow to dry.
Mix the sawdust with a wood glue or filler adhesive until you get a paste-like consistency. Press the mixture into the gaps using a putty knife. Smooth it over to ensure it's level with the floor. Once it's dry, lightly sand any rough edges and apply a finish to seal the filler in place.
For example, flexible fillers are better for filling gaps between floorboards, 2-pack fillers are more durable and can be nailed and screwed. Gel fillers that are mixed with sanding dust can produce a more natural 'wood like' repair that can be sanded and stained to match the surrounding wood.
To fill a large gap between your baseboard and floor, the best approach depends on the size of the gap. For smaller gaps (14one-fourth14 inch or less), use a flexible, paintable caulk. For larger gaps, install shoe molding, or use a foam backer rod first before caulking.
Silicone is not universally "better" than caulk, but it is vastly superior for wet environments like bathtubs and sinks. The best choice depends entirely on your project's environment and whether you need to paint over the sealed area.
As a general rule, caulk should only be used to seal gaps up to 14one-fourth14 inch (approx. 6 mm) wide. Attempting to fill wider gaps with caulk alone will cause it to sag, shrink excessively, and crack as it dries. For best results, gaps should ideally be between 18one-eighth18 inch and 14one-fourth14 inch.