Q: Does Gosford Quarries install sandstone?
A: No, as a rule Gosford Quarries does not install domestic or project stonework, however wedo still contract for specialized restoration work, for example at St Mary’s Cathedral.
We provide our customers with a list of ‘recommended’ stonemasons who have a broad range of skills and operate in many locations around Sydney. After discussions with us we may be able to point you in the direction of the stonemason best suited to your project.
Please see the attached link should you wish to speak to an installer mason on the list.
Q: How do I clean stains off my sandstone?
A: For a guide to the care and maintenance of sandstone and also a table of possible staining materials and their remedies please refer to the ‘Care & Maintenance’ Section.
Most often ‘stains’ are actually built up moss & algae which find homes in moist porous surfaces however if conditions turn warm and dry they will die off resulting in a darkened residue on the surface of your sandstone. Over many seasons this growing and dying cycle can leave the surface almost black. The remedy is to use a household bleach or ‘liquid’ chlorine which will kill the offending algae and the preferred mode of application is with bucket and sponge to minimize the chance of the ‘chlorine’ spilling on vegetation or entering the drainage system. The ‘chlorine’ will not damage your sandstone.
Should your particular problem not be found in the ‘Care & Maintenance’ please call Gosford Quarries and we would be pleased to further advise.
Q: Should I use a high pressure washer to clean my sandstone?
A: Unless you are very familiar with the operations of the pressure washing machine we would advise not to attempt this cleaning method.
The simple fact is that water blasted out from a high pressure washing machine at close range is likely to abrade the softer particles in sandstone surface and unless the pressure and distance from the sandstone is strictly controlled permanent erosion and damage may occur.
Unfortunately It is a common sight in Sydney to see the ‘snail trails’ caused by an inexperienced operator using a high pressure washing machine to remove graffiti from Heritage Building fabric.
Q: Is it easy to cut sandstone?
A: Sandstone is readily cut with a saw and or grinder with a diamond tipped blade or split with hammer and bolster. It is softer than marble and much softer than granite.
Particular care however needs to be taken to avoid breathing the fine silicon dust if you are using a dry grinder on sandstone. We would strongly advise if the stone is to be cut by any of the above methods that the operator use a dust mask to avoid inhalation and if at all possible the stone should be cut or sawn with water to avoid the issue altogether.
Of course it is recommended that you are familiar with the equipment being used and wear appropriate safety protection.
Q: Do you recommend sealing sandstone?
A: Generally we do not believe sandstone needs to be ‘sealed’ unless there is an obvious need to do so..
For many years we have seen the development of ‘sealers’ for use on porous products including sandstones. ‘Sealers’ are in fact wrongly named in our opinion. They are ‘hydophobing’ chemicals that repel water molecules and cause them to form water spheres or droplets on the surface of the sandstone. There are various solvents used to transport the ‘active water repelling ingredient’ into the matrix of the sandstone including water. However they do NOT seal the sandstone like a coating on timber floor the active chemical becomes an integral part of the sandstone surface
Internal installations like benchtops and coffee tables and exterior areas around B-B-Q will need to be ‘sealed’ to provide assistance with the sandstone maintenance.
However our observations of ‘Sealing’ products over many years are :
In our opinion the ‘hydophobing’ effect usually diminishes within 12 months or so and reapplication may become a maintenance procedure to ensure the effectiveness.
The ‘sealer’s do not stop scuff marks, dirt from foot traffic or marks caused by similar wear & tear. Nor do they stop materials like crayons, felt pens or markers of any kind.
‘Sealers’ will assist in the moping up of spills like as red wine or coffee but will not prevent staining if the agents are left on the surface for a time.
‘Sealers’ do not prevent the effects of salt crystallization and to use them as a remedy for this problem in our opinion will only accelerate the visible surface ‘fretting’. ‘Sealers’ do allow the evaporation of sub surface moisture, however if the moisture has soluble salts from the concrete or surrounding soils those salts after evaporation of the moisture will crystallize and cause a ‘fretting problem’ within the sandstone .
Some ‘sealers’ are not colour stable and may put a film of darker or lighter colour on the sandstone surface.
There are reputable sealing companies that offer products with a limited guarantee or have products that are specifically compatible with our sandstones. Please contact us for a list of these companies.
Q: The surface of my sandstone is soft and starting to crumble and there is a residue of sand on the floor?
A: Under normal conditions sandstone will not fret or crumble. There is usually a root cause problem and it is most likely relating to rising damp.
If moisture is present in building substrates or footings it will move to a location where it can evaporate. Moisture traveling through sandstone carries with it soluble salts from dissolved from concrete or sub soils. These salts are deposited near or on the surface when the moisture evaporates and the crystallization of the salt when it dries is stronger than the bond of the sandstone particles and will force the particles to break away. This is known as fretting in the stone industry.
The process is well known but the remedies are often extremely expensive and protracted. It would be best to contact us about your condition and we can refer you to a ‘rising damp’ expert to assist with the remedy.
Q: I wish to use sandstone around my swimming pool but the pool system is salt water. Is this OK ?
A: The simple answer is no. For the above reasons regarding rising damp the process of salt crystallization is very corrosive on sandstone paving and the decay may be evident only after a few months. In our experience regardless of the type of sandstone if it is porous it will suffer the effects of salt decay.
Some company’s will offer a solution whereby the stone is ‘sealed’ on all sides to preclude the entry of the saline water. If you can get a written performance guarantee from either the sandstone supplier and or the sealant applicator it may be worth the risk otherwise we would not recommend sandstone for this application.
Q: I want to have my sandstone table delivered to the rear of my property and the stones have to be carried around to my backyard. Can the Gosford Quarries truck driver do this for me?
A: Gosford Quarries have 3 contractor truck drivers delivering normally 2 loads per day into Sydney. This is approx 80 tonnes of sandstone material each day of the week!
Consequently our drivers do not assist with the unloading of sandstone. The deliveries are strapped to pallets and dropped by the use of truck mounted ‘hiab’ cranes at the kerbside or on your driveway if requested.