How do you fill holes in between tiles?

Filling in gaps or holes between tiles is a common issue that many homeowners face when installing tile. While tile is beautiful and durable, it does require some maintenance to keep the grout lines looking neat and clean. There are a few methods you can use to fill in gaps between tiles, depending on the cause and size of the holes.

Causes of Gaps Between Tiles

Before filling in tile gaps, it’s important to understand why they formed in the first place. Here are some of the most common causes of holes or spaces between tiles:

• Improper grouting – If the grout lines were not fully packed when the tile was installed, it can lead to gaps forming over time as the grout shrinks or cracks.
• Movement or shifting of the subfloor – Any movement in the substrate beneath the tile can cause tiles to shift position and open up gaps between them.
• Loose tiles – Individual loose tiles that have come unbonded from the mortar can leave holes where they meet adjacent tiles.
• Moisture damage – Exposure to excess moisture can cause grout and mortar to weaken and deteriorate, leading to widened grout lines.
• Normal wear and tear – Over time, grout can crack or crumble away leaving gaps between tiles.

Inspecting the tile gaps closely will help determine if the issue is with missing or failing grout, a bonding problem with the tile itself, or issues with the subfloor. This will guide you towards the proper repair technique.

Removing and Replacing Grout

If the gaps are caused by cracks, holes, or missing grout, a simple grout repair is likely the best solution. Here is the basic process:

1. Use a grout saw or utility knife to rake out all of the old, damaged grout, cutting down to a depth of at least 3/8 inch.
2. Thoroughly clean out the gaps with a shop vac to remove all debris and dust.
3. Apply grout sealer to the exposed tile edges to prevent staining from the new grout.
4. Mix up a batch of sanded grout that matches the old grout color as closely as possible. Work the new grout firmly into the gaps with a grout float.
5. Let the grout dry slightly and then polish the joints with a grout sponge to smooth them out.
6. Allow the grout to fully cure for 72 hours before cleaning the tiles or applying any sealers.

With this technique, you are simply replacing the same grout that was originally installed. Matching the color and texture as closely as possible provides the most seamless look. Just take care to only apply new grout where the old grout was located.

Re-Grouting the Entire Tile Surface

For more extensive grout damage or color mismatch over a large area, it may be best to regrout all of the tile joints. This involves:

• Removing all old grout with a grout saw or rotary tool equipped with a grout removal bit.
• Cleaning off the tiles and re-sealing if necessary.
• Re-grouting the entire installation with fresh grout in a consistent color.

This provides a uniform appearance across the whole tile surface. It can take more time and labor than spot grouting, but leads to a more flawless finished look.

Using Grout Caulk in Small Holes

For filling small gaps or holes less than 1/8 inch, using a grout caulk is often the simpler solution. Grout caulk has a silicone base so it can flex with any tile movement. The steps include:

1. Cleaning out the gap thoroughly and drying it.
2. Masking off the adjacent tiles with painter’s tape.
3. Filling in the hole with a well-matched colored grout caulk, tooling it smooth.
4. Allowing the caulk to fully cure before removing the tape.

Grout caulk comes in various colors to match common grout shades. The flexibility and waterproof properties of silicone allow it to adhere well and seal small problematic gaps.

Filling With Mortar or Tile Adhesive

For loose, unbonded tiles with gaps around their edges, the right material to fill holes is a tile mortar or adhesive. After cleaning the gap, pack it in well with a grout float or trowel and allow it to fully cure. This helps stabilize and re-bond the loose edges.

An expanding foam filler made for tiles can also work, injected into the gap through a nozzle. This fills any empty space completely and adds stability. Cut away any excess once it cures.

Replacing Individual Tiles

If gaps are caused by one or more loose, damaged, or missing tiles, replacing those tiles can permanently fill the holes. This may be needed for cracked, chipped, or broken tiles.

The process involves:

• Carefully cutting out and prying up the damaged tiles.
• Scraping away old thinset and flattening the area.
• Applying new thinset mortar to the back of the replacement tiles.
• Setting the new tiles into place, aligning the edges and pressing in firmly.
• Letting the thinset cure fully before regrouting.

Be sure to select replacement tiles that match the originals in terms of type, size, texture, and dye lot. This provides the most seamless appearance once repairs are done.

Filling Wide Grout Joints

In some cases, the grout joints themselves between tiles have become excessively wide, leaving large gaps. Wider than 1/8 inch, these gaps require more than just regrouting. Options include:

• Grout additive: Mixing in latex additive makes the grout more flexible and adhesive so it can fill larger joints.
• Expansion strips: Foam strips can be inserted into wider joints to take up space before filling with grout.
• Joint sealant: A silicone sealant designed for wide joints can flexibly fill and seal gaps up to 3/4 inch wide.

Be sure to clean out any old grout, debris, or caulk entirely before filling extra wide grout lines. Allow any new filler materials to fully cure before foot traffic over the tile.

Subfloor Issues Causing Tile Gaps

In some cases, the root cause of gaps between tiles is not actually with the tiles or grout itself. Underlying problems with the subfloor can lead to shifting, settlement, or lifted tiles.

Common subfloor issues include:

• Moisture damage or water exposure leading to deterioration.
• Heavy traffic and use patterns causing deflection.
• Settlement or movement of the framing beneath the subfloor.
• Insufficient subfloor thickness or lack of proper underlayment.
• Not properly fastening the subfloor to joists or framing.

Unless these subfloor problems are addressed, the same gaps and lifting will reappear in the tile over time. In worst case scenarios, the flooring may need to be completely torn out and the subfloor corrected or replaced before setting new tile.

Preventing Future Grout and Tile Gaps

While some gaps and deterioration are inevitable from normal use, you can help minimize development of tile holes or spaces by:

• Using proper installation techniques and building codes for the substrate.
• Ensuring adequate subfloor thickness and proper fastener spacing.
• Careful waterproofing in wet areas like bathrooms.
• Letting thinset and grout fully cure before use.
• Sealing grout and tiles after installation.
• Regularly applying grout sealer to protect from moisture.
• Catching loose or cracked tiles early to prevent deterioration.
• Re-grouting periodically in heavy use areas.

Repairing tile holes or gaps promptly keeps your tile floors looking great and prevents further damage. With some basic tools and materials, holes between tiles can be filled for a flawless appearance.

Frequently Asked Questions

What are some signs I have gaps between tiles that need repair?

Noticeable cracks in grout lines, missing or crumbling grout, tiles that appear loose, rocking, or sloping out of the plane of the floor, and obvious holes or spaces between tiles where you can see beneath the flooring are all signs of gaps that need repaired. Even small gaps should be addressed quickly before they expand.

Can I use sanded caulk instead of grout?

Sanded caulk is not the best option for filling gaps between tiles. While flexible, caulk will not provide the same durable, long lasting finish as cement-based sanded grout. For small joints under 1/8 inch, non-sanded grout caulk is preferable to sanded caulk. For larger holes, regrouting is recommended.

How soon can I walk on newly regrouted floors?

It’s best to avoid walking on freshly grouted floors for at least 24-48 hours to allow the grout to set up and begin curing. Wait 3-7 days before regular use of the surface and applying any sealers. This helps ensure the grout gains its full strength and hardness to withstand foot traffic without cracking.

What tools do I need to regrout tile?

A typical grout repair project requires a grout saw, carbide grout scraper, or rotary tool to remove old grout, a shop vac for cleaning, grout floats and sponges for applying new grout, sponge and buckets for washing, grout sealer, painter’s tape, and grout additive if needed. Having the proper tools makes regrouting much easier.

Should I use sanded or unsanded grout to fill gaps?

For most standard tile joints under 1/8 inch, unsanded grout is the correct choice. However, for wider grout lines between tiles or larger gaps, sanded grout provides better filling and durability. Always match the type of grout originally installed.

Conclusion

Filling in gaps between tiles helps restore the clean, finished look of a tile installation while preventing further deterioration. With some basic DIY skills, you can successfully use regrouting, caulk, mortar, or tile replacement to tackle holes or spaces of any size for a flawless tile surface. Paying attention to the cause and properly preparing the area will lead to long-lasting results. Well-sealed grout and sound substrate construction are key to minimizing future gaps.