Before You Clean or Seal — Identify the Material
One of the biggest mistakes homeowners make is treating all tiled floors the same.
Porcelain, limestone, terracotta, sandstone, and ceramic tiles all behave differently.
Using the wrong method can lead to:
• Staining
• Patchy surfaces
• Residue build-up
• Sealer failure
• Moisture issues
Before applying any cleaner or sealer, you should identify what material you’re working with.
Porcelain & Ceramic Tiles
Porcelain and ceramic tiles are manufactured and generally low-porosity.
They are typically:
• Smooth to the touch
• Dense
• Water-resistant
• Uniform in appearance
Most porcelain tiles do not require sealing — but the grout between them often does.
(See: Do Porcelain Tiles Need Sealing?)
If your tile surface is smooth and water beads rather than darkens it, it is likely porcelain or glazed ceramic.
Limestone
Limestone is a natural stone and noticeably more porous than porcelain.
It often has:
• Soft colour variation
• Natural fossil markings
• A matte or honed finish
• Slight texture underfoot
If water darkens the surface temporarily, it is likely porous natural stone.
Limestone typically requires breathable protection.
(See: Do Limestone Floors Need Sealing?)
Why Limestone Floors Become Dull Over Time
Terracotta
Terracotta is clay-based and highly porous.
It is usually:
• Warm in colour (reds, oranges, browns)
• Matte or lightly sealed
• Slightly textured
• Sensitive to moisture
Terracotta almost always requires sealing.
Old sealers can fail and cause sticky or patchy surfaces.
(See: Why Your Terracotta Floor Feels Sticky)
If your terracotta looks glossy or plastic-like, it may have an old topical coating.
(See: Removing Sealer from Terracotta)
Sandstone & Flagstone
Sandstone is a natural sedimentary stone often used indoors and outdoors.
It typically has:
• Visible grain
• Layered appearance
• Textured surface
• Variation in tone
It is porous and reacts to moisture movement.
Outdoor sandstone is particularly affected by:
• Rain
• Salt deposits
• Freeze/thaw cycles
(See: White Powder on Patio Slabs?)
Natural Stone Issues
Aggressive cleaning methods can also cause surface damage.
(See: Why Pressure Washing Can Damage Sandstone)
Grout Matters Too
Regardless of tile type, grout lines are usually cement-based and porous.
They absorb dirt and moisture faster than the tile surface.
If your floor looks dirty even after mopping, grout may be the cause.
(See: Why Your Tile Floor Still Looks Dirty After Mopping)
Proper grout cleaning and sealing significantly improves overall appearance.“For more detail, see: Why Is My Grout Turning Black?”
The Simple Water Test
A basic way to assess porosity:
Place a small drop of clean water on the tile surface.
If it darkens the surface temporarily, the material is porous.
If it beads and remains unchanged, it is likely non-porous.
This is not a full diagnosis — but it provides an initial indication.
Why Identification Comes First
Different materials require different approaches to:
• Cleaning
• Stripping
• Moisture management
• Sealing
Treating limestone like porcelain, or terracotta like ceramic, can lead to unnecessary problems.
Before using stronger cleaners or adding sealer, identify the material first.
Why Grout Looks Clean When Wet But Dirty When Dry
Where to Go Next
Choose the guide that matches your floor type:
• Porcelain & Ceramic Restoration Guide
• Limestone Tile Restoration Guide
• Terracotta Tile Restoration Guide
• Sandstone & Flagstone Restoration Guide
• Grout Cleaning & Restoration Guide
Or explore the full collection here:
Floor Restoration Guides Collection
Common Problems by Area
Grout & Tile Issues:
• Why grout turns black
• Why grout gets dirty quickly
• Why grout looks clean when wet but dirty when dry
• Why your tile floor still looks dirty after mopping