What is the joint between floor tiles
The joint between floor tiles are often thought of as grout lines, but tile movement joints (also called expansion joints or control joints) have a very different purpose. These gaps are intentionally left during the assembly of the tiles, filled with flexible materials or protected by metal profiles, and are used to absorb stress caused by temperature changes, structural movement and dynamic loads. Without these gaps, tiles will crack, collapse or delaminate within a few months, especially in large areas or areas subject to high stress.
1. Why are tile expansion strip so important in tile installation?
Tiles and stones are rigid materials with little flexibility. So when the substrate expands, contracts, or deforms due to temperature, structural displacement, humidity changes, etc., bulges, cracks, grout breakage, etc. will occur, causing huge repair costs.
- Heat: Dark tiles can heat up to 74°C (160°F) in the sun, expanding 2-3 times faster than in shaded areas
- Structural displacement: Building settlement, earthquake displacement, or live loads (such as forklifts in warehouses)
- Humidity changes: Concrete substrate shrinks during the curing process, causing tiles to crack
2. Where do I need expansion joints?
We recommend expansion joints where tiles meet walls, columns, or curbs. If you are laying tiles over a large area, we also recommend floor expansion joints, usually every 24 feet indoors, every 8-12 feet outdoors, and every 5 feet for radiant heated floors to prevent cracking of tiles due to floor movement and thermal expansion and contraction.
3. Three Critical Types of Tile Movement Joints & Their Functions
|
Joint Type |
Purpose |
Placement Guidelines |
|
Perimeter Joints |
Isolate tile from restraining surfaces |
All wall-floor junctions, around pipes/columns; min. 6mm width |
|
Structural Joints |
Mirror substrate control joints |
Must align exactly with concrete saw cuts; width ≥ substrate joint |
|
Intermediate Joints |
Subdivide large areas into smaller sections |
Every 8–10m indoors; 3.5–5m outdoors; max. 25m² zones for heated floors |
4. Why do metal tile control joint outperform silicone and PVC?
While silicone sealants are common, they degrade under UV exposure and are susceptible to stains and mold growth. PVC strips deform under heavy loads and have a service life of no more than 8 years. Aluminum and stainless steel profiles address these deficiencies with engineered durability:
A. Aluminum tile expansion joints (e.g. Ghonor MJ Series)
- Core Design: Two aluminum rails + flexible silicone/PVC inserts (±20-30% of movement capacity)
- Service Life: 30+ years – perfect for airports, malls, and hospitals with more than 300,000 foot traffic.
- Customization:
- Height: 8-22.5mm (suitable for a wide range of tiles from thin ceramic to thick stone)
- Surface treatment: brushed, powder coated (RAL colors), wood grain, marble texture
- Best suited for: commercial floors, pool decks and outdoor areas with strict corrosion resistance requirements
B. Stainless steel tile movement joints
- Core design: 304 grade steel legs + bonded polyurethane rubber/silicone/PVC inserts
- Lifespan: 40+ years - withstands industrial cleaners and salt spray (coastal/pool areas)11
- Load capacity: supports vehicle traffic (e.g. supermarket floors, warehouses)
- Best suited for: laboratories, food factories, sterile environments requiring hygiene and high strength performance
Material Comparison Table
|
Feature |
Silicone Sealant |
PVC Strips |
Aluminum Profiles |
Stainless Steel Profiles |
|
Lifespan |
10–15 years |
5–8 years |
30+ years |
40+ years |
|
Movement Capacity |
±15–25% |
±10% |
±20–30% |
±15–20% |
|
UV Resistance |
Poor (yellows) |
Poor (cracks) |
Excellent (powder-coated) |
Excellent |
|
Chemical Resistance |
Moderate |
Low |
High |
Exceptional |
|
Cost Efficiency |
Low upfront |
Low upfront |
Saves 80% long-term repairs |
Highest ROI in harsh environments |
5. Metal expansion joints are critical
- Large-format tile installations:
24-inch by 48-inch tiles transfer more displacement energy, so it is recommended to place joints every 12 feet (about 3.7 meters) and use silicon-core aluminum profiles.
- High-rise buildings and seismic zones:
Aluminum profiles can absorb differential movement of the floor slab.
- Pool decks and beachfront patios:
Stainless steel resists salt/chlorine corrosion; bronze finishes hide calcium stains.
- Heated flooring:
Thermal cycling requires joints every 5 meters; aluminum's thermal conductivity prevents thermally induced warping.
- Proven in the field:
Ghonor's powder-coated aluminum joints withstood five hurricanes on a Miami hotel patio (1,200 square meters), while PVC joints cracked in the second year.
Hot recommend
We recommend our tlle movemnt joints to provide you with efficient and safe tile installation solutions.
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Leah Liu
Hello there! I am Leah. I have worked in the building materials industry for over 10 years. I want to share my experience here - let us make progress together!