Blackstone Industrial (Foshan) Limited

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I. General Knowledge Related to Porcelain tiles

1. How to select good porcelain tiles? Is it true the lower its water absorption rate is, the better the quality of the tile is?
Some people say that the lower its water absorption rate, the better the quality of the tile. In the strict sense, this saying is reasonable but not always true. Requirements for water absorption rate of porcelain tile varies with the place where the tile is going to be installed.
Water absorption rate of floor tile specified by national standards is E ≤0.5%. The higher the water absorption rate is, the lower the tile density is, meaning water can more easily penetrate the tile.
For wall tile, water absorption rate should be in the range of 10%≤E≤16% according to national standards. Because wall tiles need to be laid vertically, it has to be a bit adhesive. If water absorption rate of wall tiles is too low, the tiles may not be laid stably, risking cracking or peeling.

2. Does porcelain tile have radioactivity?
The radioactivity of porcelain tile mainly comes from a raw material called zirconium silicate, which is mainly used for whitening. Some porcelain tile manufacturers add a lot of zirconium silicate in their products because the raw materials they use are not white enough, resulting in high radioactivity of their porcelain tiles.
Blackstone hardly uses zirconium silicate in our porcelain tiles and our building decoration tiles have passed the China Compulsory Certification. You can use our products without any worries. Many natural materials contain small levels of radioactive substances. The radioactivity of porcelain tile is much lower than that of natural marble or granite and is nothing that should concern you.

II. Questions Related to Porcelain Tile Quality

1. What are the possible reasons that affect flatness of porcelain tiles and what are the solutions to avoid unevenness?
a. Construction Problems

The porcelain tiles may not be laid with a consistent direction or the four corners of the tile are not properly aligned.
Construction personnel should pay attention to making appropriate adjustments when laying tiles so as to achieve the best paving effect.
b. Uneven Ground
Check if there are any protruding objects on the ground to avoid uneven paving.
c. Inconsistent Thickness of Cutting Processed Tile
Check if there are any processed tiles coming in with different thicknesses from others and make some modification if necessary when you lay them.
d. Whether The Error Is Restricted Within a Reasonable Range
Porcelain tile may deform during high temperature firing, therefore, a certain quantity of errors are allowedaccording to the national standard. Leave some gaps when laying the tiles to reduce the negative effects caused by cement shrinkage and improve paving flatness.

2. Do imparities and pinholes on the tile surface affect the quality of the porcelain tile?
Porcelain tile is made of natural mineral soil materials such as clay and feldspar, and are produced through grinding, mixing, pressing and firing. In those natural mineral soil materials, there are iron and other impurities which are impossible to be removed completely, although our company has adopted strict measures to remove as much iron and other impurities in the process of our building decoration porcelain tile production as we can.
Impurity is inevitable in the porcelain industry. The national standard for surface quality of porcelain tile specifies that at least 95% of the tiles in one batch have no significant defects seen from a distance of 1m. A few color points and small pinholes on the tile surface are not obvious flaws.

III. Questions about Construction

1. How to calculate the number of porcelain tiles needed?
Calculated by piece: decoration area÷ single tile area×[1+3% (wastage)]=required tile piece quantity.

2. Is it necessary to leave some gaps when laying porcelain tiles?
Generally, we need to leave a 1~2mm-wide gap between each tow piece of tiles when laying edge-grinded wall tiles or floor tiles and an about 3mm-wide gap when laying non-edge-grinded wall tiles or floor tiles. If you want special paving effects, you can leave wider gaps when laying the porcelain tiles.
The wall and cement may expand or shrink after tile paving. Leaving gaps when laying porcelain tiles may avoid tile cracking and help extend the service life of the porcelain tile.

IV. Porcelain Tile Quality Standards

Technicalstandard Industrialstandard Standardrequest Europeanstandard BLACKSTONE tile performance
Water absorption ( %) GB/T4100.1-1999 ≤0.5 ≤0.5 ≤0.1
Breaking strength (N) GB/T4100.1-1999 ≥1300 ≥27 ≥1300
Rupture modulus (Mpa ) ≥ 35 ≥40
Length ( %) GB/T4100.1-1999 ±1.0 ±0.6 ±0.5
Width ( %) GB/T4100.1-1999 ±1.0 ±0.6 ±0.5
Thickness ( %) GB/T4100.1-1999 ±5.0 ±5 ±0.5
Surface GB/T4100.1-1999 ±0.2 ±0.5 ±0.1
Flatness (%)
Side GB/T4100.1-1999 ±0.2 ±0.5 ±0.1
Straightness ( %)
Squareness ( %) GB/T4100.1-1999 ±0.2 ±0.6 ±0.1
Wearing GB/T4100.1-1999 ≤175 <205 ≤150
Strength ( mm3)
Linear thermal expansion coefficient GB/T4100.1-1999 <9×10-6K-1 <7×10-6K-1
Thermal vibratility GB/T4100.1-1999 No crackle or crack after rapid cooling and rapid heating cycle for 10 times Approved Matched
Frost resisting GB/T4100.1-1999 No crack or spalling after frosting EN176 Matched
Property Resistance test
Glossiness GB/T4100.1-1999 ≥55 ≥65
Radioactivity GB/T4100.1-1999 1Ra≤1 1r≤1.3 1Ra≤0.6 1r≤1.2

V. Common Maintenance Methods to Home Use Porcelain Tile

1. Avoid Scratching
Avoid using sharp metal objects, glass ceramic objects, or other hard object to knock or rub the floor tile surface so as protect the glaze from being damaged.
If there are slight scratches on the porcelain tile surface, apply toothpaste to the scratches and wipe them with soft clean cloth, then apply a small amount of floor wax to the tile surface. After the wax is dry, clean the tile surface with clean cloth, then the floor tile may be as clean as a new one. If the tile is seriously damaged, please ask a professional to repair it or replace it in time.

2. Remove Moisture
After cleaning the porcelain tile wall in your house, open the door and the window to let the air circulate so as to expel the moisture on the walls tiles. In humid environments, you can clean your tiled walls with dry cloth for a second time after you have cleaned them with wet cloth, and then turn on the air conditioner to remove moisture.

3. Clean Stains
You can use soft clean cloth to remove common stains on your wall or floor tiles. We suggest you clean severe stains with a piece of wet, but not dripping cloth.

4. Mould Prevention
The joints between each tile can be cleaned with cleaning cream irregularly and then applied with a layer of waterproof agent to prevent molds from growing.

VI. Common Methods to Cleaning Stains on Porcelain Tiles

Staintype Cleaningagent type Commoncleaning products on the market
Ruststain or tea stain Acidiccleaning agent Porcelaintile rust remover, diluted hydrochloric acid solution
Paint Acidiccleaning agent Dilutedhydrochloric acid solution
Limestain, cement mortar, tile grout Acidiccleaning agent Concretelayer cleaning agent, diluted hydrochloric acid solution
Beer,wine Alkalinecleaning agent Washingpowder, detergent
Oil,fat, ice cream Alkalinecleaning agent Porcelaintile degreaser, detergent
Glue,oil paint Organicsolvent Bananaoil, rosin liquid
Markingpen stain, oil pen stain, rubber stain Organicsolvent Acetone,trichloro ethylene
Stainmade by metal or pencil scratching Sodiumhypochlorite diluted solution Bleach
Ink,coffee or juice stain Sodiumhypochlorite diluted solution Bleach
Stainscaused by discoloration of carton or woven product Sodiumhypochlorite diluted solution + Acidic cleaning agent Bleach+ Diluted hydrochloric acid solution