How to clean Marble (also applies to limestone, slate and granite)
If you are more inclined to attempt to clean a headstone yourself then please do read the following. If you have any questions please email us
here and we will try to answer your questions as soon as possible.
Please note that we are not advocating the cleaning of every type of headstone or memorial, indeed we believe that there are some types that should be left alone. You should always check with the church or local authority as to the policy on refurbishment, for example, you may have traced a relative to an eighteenth century grave but would you want to clean it! I suspect no and I further suspect it may even be strictly against the regulations of the church or parish or other regulatory body.
You should also note that some mosses, lichens or other growths may be protected by law, if you are in any doubt you should seek advice from the local authority or parish council etc. Please, please, please do not use abrasives, acid or power washers on any headstone or memorial before seeking advice - however well meaning you may be, you could end up doing more damage!
Assuming you have recieved the ok to go ahead and clean your memorial or headstone, the following method can safely be used on most types of old headstones found in cemeteries in England today. Before we start the actual cleaning process, you should ask yourself two basic questions.
1. Is the headstone or memorial actually cleanable?
This may sound strange but you should examine the stone first and if it shows any sign of delamination, scaling, flaking or other deterioration then please, do not attempt to clean it! You will only cause more damage to it. If the memorial or headstone is cracked, broken, leaning or has pieces broken off then again do not attempt to clean or otherwise repair it. In this instance you should always ask a stonemason to inspect it and make recommendtions as to it's refurbishment. The mason should be a member of the
National Association of Memorial Masons and they can be found following the link.
If your memorial or headstone is under five years old and is suffering from any of the above then the original supplying company should be asked to return and complete the re-setting or making good of the memorial.
2. What kind of stone is it?
The type of stone used in the construction of the headstone or memorial will usually determine the the type of cleaning method used. The most common types of headstones you may encounter will be marble, limestone or granite. There are other types of course and these can be wood, slate, sandstone and - would you believe it - plastic - (though thankfully this material is not commonly used in this country!!!)
Weathered marble can often resemble slabs of concrete with very rough surfaces covered in moss or other organic growths.
This picture shows a marble headstone that has been laid over because it had become unstable on it's base. See the bottom right hand corner, this is what the marble would have looked like when it was first installed.
Cleaning a headstone like this will never get it look like it has just been installed but nontheless you will be suprised at just what can be achieved using safe cleaning methods.
If the headstone has lead lettering that is loose or missing then this is a good indication that significant erosion of the surface of the stone has already taken place and this means that any polished surface has already gone. Short of having the stone removed by a mason and re-dressed, re-polished and re-lettered the best you can hope for is a thorough clean and then to re-letter in situ.
This close up of a marble headstone clearly shows the weathered surface and the holes in the carved letter 'N' where lead is beaten into it to form pins that hold it in place. I would suspect that this lead has only recently dropped off as the newly exposed stone underneath is very clean. Note again the colour of the st
one where the 'N' is. The raised profile of the letter 'I' shows how much of the surface of the stone has weathered away, it would have originally been flush with the surface.
Please note also the sugery texture of the stone where the letter 'N' is. This is a chracteristic of weathered marble and indeed in some extreme cases whole stones can 'disolve' into lumps of sugery like powder! A stone like this has weathered too much for this type of cleaning and would need re-surfacing completely.
For the purpose of this article the cleaning method employed is safe to use on marble, limestone or granite.
Expectations.
You should be careful not to expect too much from any cleaning process. The cleaning should be just that, cleaning and not an attempt to return the stone to the way it looked when erected. You want the memorial or headstone to looked cared for and that's understandable and to be encouraged but quite often it will not be possible to remove all the stains or blemishes from the stone.
Be as gentle as you can.
It doesn't matter what type of stone you are trying to clean but always remember, be as gentle as you can and always use the least agressive method to accomplish the cleaning process. This picture shows a headstone that has been completely ruined by some well meaning but misguided person being allowed to run riot with a high pressure water gun! There are even some grave 'care & maintenence' companies who use these and even sand blasting machines! These types of abrasive 'techniques' will only serve to hasten the destruction of the memorial or headstone as they actually take away some of the surface of the stone. Please, please, please don't let anyone near the stone with one of these.
Don't be tempted to use bleach or other harsh chemicals such as patio cleaner or brick acid. These, mixed in the wrong amounts or even used neat, can seriously damage the stone. Do not use wire brushes or metal scrapers - ever!
Plan your visit
Please make sure that you check with the cemetery or churchyard that there are no funerals planned for the day you want to go and clean. After all, would you want someone to be working away close by if you were attending a funeral? I think not so it's better to check first, especially if you are travelling long distances.
Tools you will need.
You will need to take a few basic items as well as a couple of more specialised chemicals with you when you go to clean the headstone. These include :-
A non-ionic detergent such as photoflo, pictured right, which can be obtained from Jessops. This is PH nuetral and will not harm the stone. As a general rule you should mix it at home in a bucket of cold water, adding about one or two ounces only to a gallon of water and then use this solution to fill up one of your hand sprayers. Make sure you label the sprayers!
Lets Clean
Start on the back of the headstone first. Why, I hear you cry? Well, if you start on the front and after much hard work, reveal the stone and inscription in all it's glory, you may well not want to continue the hard work to the rear! Actually it also serves a more important service, starting on the back will let you know if the cleaning method is going to be successful or if the cleaning solution is too harsh or unsuitable. Quite often you will also see on later memorials a plot number and supplying company mark as in this picture here.
Start by completely saturating the stone with the clean water. This is where the hand sprayer comes into it's own. You can quite easily wet the stone without wasting too much percious water. After wetting the stone, lay some of the kitchen towels around the base so that the cleaning solution does not enter the soil. Spray on some of the cleaning solution, starting at the base first and working upwards. Use the softest brush first and work in a random orbital motion again from the bottom up.
Do not let the stone dry and if necessary spray more water on and more cleaning solution as needed. Periodically wash off the scrubbed area to avoid streaking and gradually move upwards applying first more fresh water and then the cleaning solution before scrubbing. If the softest brush doesn't seem to move much, use a harder bristled brush. Use the scrapers to scrape away any moss or lichen growth and use the toothbrushes for intricate detailing areas.
Be patient and you may have to repeat the process several times before you are satisfied with the results.
When you have finished cleaning and have again washed down with clean water you can apply some boicide and this will help stop other moss and lichens from colonizing the surface of the stone. Please remeber though that the natural weathering process of wet, dry, wet and dry again etc will eventually leach the boicide out of the stone over time. This is normal and to be expected.
After you have cleaned the stone and treated with the boicide you will have to wait for the stone to dry sufficiently to see your handiwork. As it dries the stone will become lighter. Don't be discouraged if it doesn't look like new, remember what we said about expectations.
If you have found this article useful or would like to comment on any aspect of it we would appreciate your feedback. Please contact us
here and we thank you in anticipation.