Since Memorial day will soon be here, I thought this would be some useful information.
Yesterday I had a chance to attend a community preservation workshop. One of the classes demonstrated to us how to properly clean a headstone. Since our family struggled with this some years back, I wanted to write down what I learned for future reference.
1. Headstones should first be cleaned while dry with a soft brush (preferably soft natural bristles).
2. Then soak the stone with water and keep it wet while you work on it with the soft brush. You can use a wooden stick, such as a popsicle stick, to help clean out lichen and such. If more than that is needed you can use a product such as D/2 or Orvus.
3. You should clean the stone when the temperature is above 40F. If it is a hot day, you should let the water warm up before you put it on the hot stone. No cold water on hot stone.
4. Things you should NOT do or use include: bleach, wire brushes, power tools, pressure washers.
5. They don't advise putting sealants on the stone. If you feel you must put something on, make sure it says it is breathable or permeable ...not water proof.
6. Stones should not need to be cleaned oftener than every 5 years.
7. You should not use Portland cement to repair cracks or as mortar. Marble and Limestone are particularly vulnerable to acids. So no acidic products should be used. (Lichen roots are acidic! Who knew?) You want to use only pH neutral things.
8. Unrelated to cleaning, but still good to know: Doing rubbings of headstones is damaging to them and should not be done.
