How to clean headstones

How to clean headstones

GK Pro and Greener Kleener have been formulated for use as a treatment for bacterial staining and a memorial monument cleaner – they both fulfil all sustainability recommendations required of the National Association of Memorial Masons professional guidelines for cleaning.

GK PRO can be used on memorial stone manufactured from Granite, marble, fieldstone, concrete, sandstone and limestone polished or honed.

Be warned - using the wrong product could cause staining or even create hairline cracks, these cracks can become major issues when rainwater and moisture entering the stone, freezes resulting in large cracks and complete breaks.

GK Pro and Greener Kleener can also be used on headstones created from wood, bronze, iron, or any other similar materials regardless of shape, colour, finish, and types of base.

Algae and superficial contamination die within minutes of application and continue to self-cleanse over a long period. The fungi responsible for black incrustations will die within two hours of application – though nature can take some weeks to remove completely. If the black dye (produced to protect itself from UV) remains visible after 8 weeks, it may be necessary to bristle brush in order to remove the weakened staining completely.


A step-by-step guide on how to clean headstones, memorials and statues using GK PRO

You should clean your headstone of bacterial staining as needed.  How often its needed will depend upon weather conditions and the environment within which the stone sits (wooded area etc.)

The steps for general cleaning are as follows:

STEP 1:  Remove excess vegetative growth such as leaf mould, moss lichens by brushing or scraping

STEP 2:  saturate stone in GK PRO in a water dilution of: 80:1 for light to moderate bacterial staining

And 40:1 for heavy bacterial staining

STEP 3: Allow to evaporate naturally

The stone will self-clean with natural weather cycles over two or three weeks. 


The process may be hastened by, following STEP 2: vigorous brushing of stone, rinse with clean water and follow with a light spray of GK Pro. If using Greener Kleener a dilution of 2:1 for heavy staining or 3:1 for light staining will suffice.

No matter the material never clean headstones using a high pressure washer, strong chemicals or abrasive, wire or metal scrubbers.


A pure product

GK Pro and Greener Kleener do not contain any acids, solvents or damaging alkaline such as sodium hydroxide – these products are known to be oxidisers and re not recommended for gravestone cleaning.

GK Pro and Greener Kleener are Quaternary Ammonium DDAC Biocides, DDAC is a natural products derived from Soya bean – it is a natural surfactant and foams like washing up liquid.  Like a magnet is attracted to metals the active ingredient in GK Pro is attracted to living biofilms. GK Pro disinfectant depletes itself by giving off its energy when attacking living bacteria (cationic action), this is the mark of its biodegradability.

(As with any cleaning product test on an inconspicuous area first)


We recommend when using Greener Kleener to wear appropriate protective clothing; we are happy to advise on suitable items for this task.