Fiber cement efflorescence chalking and fading is not the same thing as efflorescence and the siding is most likely painted not stained.
Efflorescence cement siding.
The stains are normally white and are present in darker colors more than white or pale colors due to the contrast created by the chemical reaction.
It is caused when water soluble salts are present in the concrete material which comes on to the surface while evaporation of water from the concrete.
It can happen even though the siding materials have been properly installed.
While not considered a warranty issue for these reasons certainteed is still concerned with your ultimate satisfaction.
Paint pigments will fade with sun exposure.
Different qualities of paint will fade at different rates.
Efflorescence will be triggered by low temperatures humidity condensation and rain.
To recap efflorescence is the result of a natural process that can occur in cement based materials.
Efflorescence is caused when soluble salts and other water dispersible materials come to the surface of concrete and mortars.
And darks have more room to fade than lighter colors.
Efflorescence can form a thick layer on the surface which can completely hide the concrete s color or as in your case create unsightly white patches.
Actually everything fades with sun exposure.
If efflorescence occurs it can be remedied with.
Sometimes over time efflorescence can appear on fiber cement siding.
It is the result of a process in which moisture draws salt crystals to the surface evaporates and leaves a chalky substance behind.
Causes usually efflorescence is primarily composed of calcium carbonate formed when leached calcium hydroxide ch from within the concrete reacts with carbon dioxide in the atmosphere.
Soluble compounds in the masonry or adjoining materials moisture to pick up the compounds and carry them to the surface evaporation or hydrostatic pressure that causes the solution to move if any one of these conditions is eliminated efflorescence will not occur.
Efflorescence is a naturally occurring white powdery deposit that can appear on cement based building materials including bricks cement walls grout and fiber cement.
A combination of three common circumstances causes efflorescence.
Efflorescence is a naturally occurring white powdery deposit that can appear on cement based building materials.
Efflorescence in concrete is a whitish coloured powdered deposition of salts on the concrete surface that is formed due to evaporation of water from the concrete.
Concrete can be stained when salts and other materials will come off the concrete surface.
Once inside the water dissolves salts and other minerals in the substrate.
It s induced by low temperatures moist conditions condensation rain dew and water added to the surface of fresh concrete to assist troweling.