Porous, natural stone needs to be allowed to breathe. Seal your limestone with a fully breathable penetrating sealer.
All stone must be allowed to release vapour. In other words, must breathe. If the pores of limestone are totally blocked, vapour will condense within the stone, and the stone will become saturated with moisture which can lead to numerous problems.
Moisture can also carry soluble salts which are often deposited on the surface of the stone (efflorescence). If the salts are not allowed to escape to the surface, they will be deposited in the pores of the stone causing deterioration.
Stone has an internal structure that is not totally solid. There are two physical properties found in limestone: pores and capillary structures that are interconnected. The structure, size and orientation of these networks affect the degree which moisture can migrate by capillary action through the stone.
Moisture migrating through natural stone is called "moisture vapour transmission"
For example: Moisture present in the ground can be wicked or drawn up into the limestone by capillary action. The porosity of the stone- that is the amount of voids in the stone and its permeability – a network of pores, move the moisture vapours like a sponge through the stone. The vapour is then released into the atmosphere.
If natural vapour transmission is not allowed to take place the moisture gets trapped and can cause chemical and mineralogical changes within the stone. This action of decay in natural stone may take the form of pitting, spalling, flaking and oxidation.
Using a topical coating or polymer on your natural stone will essentially cause the problems of blocking the necessary vapour transmission process your stone needs, so when it's time to restore your natural stone surface, think twice about the quick fix alternatives of just coating the surface.
A natural stone restoration expert will be able to assess and recommend the correct procedure to keep your natural stone healthy and happy.
Sedimentary stone such as limestone consists mostly of fossilised material found in ancient sea, lake and river beds. Pores develop as a result of compaction of various minerals, organic material secondary older stone from the area and sediment. Due to the process an unlimited variety of pore sizes and shapes are prevalent in sedimentary stone.
Unsealed limestone surfaces are highly porous and susceptible to permanent staining from everyday spills. Sealing is very important if you want to protect your limestone against unwanted staining and deterioration. If you have a limestone tiled floor, you will know that it absorbs liquids very quickly.
The primary function of a stone sealer is to provide stain resistance to a porous stone. Red wine, oil and grease in particular can result in damage that may be impossible to remove without the use of heavy resurfacing machinery. Although sealing limestone won't completely stop liquids from absorbing into it, it will give you more time to wipe spills away.
Cleaning and maintenance of limestone flooring can also be more difficult when left unsealed as surface contaminants will quickly absorb into the porous limestone structure making them difficult to remove.
It is strongly recommended to apply a deep impregnating sealer to limestone floors that provide long lasting protection and stain resistance.
Choose a breathable deep penetrating limestone sealer
Australia's produce non-solvent sealers that are easy to apply, using a brush, roller or sprayer and will dry within a few hours. These penetrating, impregnating limestone sealers are available in a dry, invisible finish or in a slightly wet, colour enhancing effect.
is a premium penetrating sealer that you can use both for interior and exterior limestone tiles. This product penetrates deep in the stone, creating an invisible barrier against water and oil based stains. At the same time, it allows any built up vapour to escape. is well known because of its special molecular structure, which makes this sealer more resistant than other products.
Choosing a sealer
- Quality long-lasting deep penetrating, impregnating sealer.
- Thoroughly and deeply clean limestone prior to application.
- Correct application and amount of required coats.
Topical Sealers (film Forming)?
- Tend to abrade easily, leading to obvious areas of scuffing or wear
- Will need to be re-applied quite regularly
- Can build-up over time to impart a varnish-like appearance
- Lower quality coatings tend to turn yellow when exposed to UV light (sunlight)
- Trap moisture in the substrate itself, leading to problems with efflorescence or damage
Penetrating (Breathable)
Impregnating penetrating sealants actually penetrate into the limestone substrate, soaking into the microscopic pin-holes and open fissures which make up its natural texture. A clear impregnating sealer won't change the look or feel of your sealed limestone, won't affect the stone's ability to release vapour and will last much longer than film forming sealers.
- Longer lifetime as the protection is contained within the substrate, and not simply on the surface
- Not affected by UV light
- Allows the stone to 'breathe', retained moisture can escape
- Surface does not become slippery
