How Much Sealer Do I Need?
Material | Porosity | Surface Texture
How Much Sealer Do I Need?
Material | Porosity | Surface Texture
How Much Sealer Do I Need?
Wondering how much sealer you need for your concrete, pavers or natural stone?
Unfortunately, there isn’t one coverage rate that applies to every surface. The amount of sealer required can vary significantly depending on the material being sealed, how porous it is, its condition, the type of sealer being used and the way it is applied.
This is why coverage rates should always be treated as a guide rather than a guarantee.
At WA Sealers, we recommend considering the surface itself first, then checking the recommended coverage rate for the particular sealer you intend to use.
Why Does Sealer Coverage Vary?
Two areas measuring exactly the same number of square metres can require very different quantities of sealer.
The main factors affecting sealer coverage include:
- Type of concrete, stone or paver
- Surface porosity
- Age and condition of the surface
- Surface finish and texture
- Previous sealers or treatments
- Surface preparation
- Number of coats required
- Application method
- The particular sealer being used
- Whether the product is supplied ready-to-use or as a concentrate
Understanding these factors will give you a much more accurate idea of how much product your project is likely to require.
How Much Sealer Do I Need?
Wondering how much sealer you need for your concrete, pavers or natural stone?
Unfortunately, there isn’t one coverage rate that applies to every surface. The amount of sealer required can vary significantly depending on the material being sealed, how porous it is, its condition, the type of sealer being used and the way it is applied.
This is why coverage rates should always be treated as a guide rather than a guarantee.
At WA Sealers, we recommend considering the surface itself first, then checking the recommended coverage rate for the particular sealer you intend to use.
Why Does Sealer Coverage Vary?
Two areas measuring exactly the same number of square metres can require very different quantities of sealer.
The main factors affecting sealer coverage include:
- Type of concrete, stone or paver
- Surface porosity
- Age and condition of the surface
- Surface finish and texture
- Previous sealers or treatments
- Surface preparation
- Number of coats required
- Application method
- The particular sealer being used
- Whether the product is supplied ready-to-use or as a concentrate
Understanding these factors will give you a much more accurate idea of how much product your project is likely to require.
1. What Material Are You Sealing?
The first question to ask is what type of surface are you sealing?
Different materials absorb liquids at very different rates.
Highly porous materials such as some limestone, sandstone, reconstituted limestone and porous concrete can absorb considerably more sealer than dense concrete, granite or other low-porosity surfaces.
Even within the same material category there can be significant differences.
Two different concrete pavers, for example, may look similar but have very different absorption rates depending on how they were manufactured.
This means you should never calculate your sealer requirement based on area alone.
2. How Porous Is The Surface?
Surface porosity is one of the biggest factors affecting how much sealer you will need.
A porous surface contains more open pores and voids for the sealer to penetrate. As a result, it will generally use more product per square metre.
A dense surface absorbs less product and will normally provide greater coverage.
An easy way to get an indication of porosity is to place a small amount of clean water onto the surface.
If the water absorbs quickly, the surface is likely to be relatively porous.
If the water remains sitting on the surface for some time, the material is likely to be denser.
If the surface does not darken when you wet it, then it is non-porous. More than likely there is an existing sealer still active.
3. Surface Texture Makes A Difference
The stated size of an area doesn't always represent the true amount of surface you are sealing.
A rough, textured or exposed surface has considerably more actual surface area than a perfectly smooth slab.
Examples include:
- Exposed aggregate
- Rough limestone
- Sandstone
- Textured concrete
- Tumbled pavers
- Split-face stone
These surfaces may therefore require more sealer than a smooth or polished surface covering the same number of square metres.
4. Surface Preparation Can Affect Coverage
Correct preparation isn't only important for the performance of your sealer—it can also influence how evenly the product is absorbed.
Dirt, oil, efflorescence, existing coatings and other contaminants can prevent a sealer from penetrating consistently.
Before sealing, the surface should be prepared according to the requirements of the particular product being used.
If an existing coating or incompatible sealer is present, stripping is often required before applying a new product.
Never use additional sealer to compensate for poor surface preparation.
Getting the substrate right first usually provides a more consistent finish and better long-term performance.
5. Different Sealers Have Different Coverage Rates
Not all sealers are designed to be applied at the same rate.
Some penetrating sealers are supplied ready to use, while products such as our Water Based Sealers concentrates are diluted before application.
For example, Pro Seal 896 is supplied as a concentrate and is normally diluted with water before being applied. The diluted product is generally applied at approximately 5–10m² per litre, depending on surface porosity.
Other penetrating sealers may have very different application rates depending on their formulation and the substrate they are designed to protect.
For this reason, always check the coverage information for the specific product rather than using a general sealer coverage figure.
1. What Material Are You Sealing?
The first question to ask is what type of surface are you sealing?
Different materials absorb liquids at very different rates.
Highly porous materials such as some limestone, sandstone, reconstituted limestone and porous concrete can absorb considerably more sealer than dense concrete, granite or other low-porosity surfaces.
Even within the same material category there can be significant differences.
Two different concrete pavers, for example, may look similar but have very different absorption rates depending on how they were manufactured.
This means you should never calculate your sealer requirement based on area alone.
2. How Porous Is The Surface?
Surface porosity is one of the biggest factors affecting how much sealer you will need.
A porous surface contains more open pores and voids for the sealer to penetrate. As a result, it will generally use more product per square metre.
A dense surface absorbs less product and will normally provide greater coverage.
An easy way to get an indication of porosity is to place a small amount of clean water onto the surface.
If the water absorbs quickly, the surface is likely to be relatively porous.
If the water remains sitting on the surface for some time, the material is likely to be denser.
If the surface does not darken when you wet it, then it is non-porous. More than likely there is an existing sealer still active.
3. Surface Texture Makes A Difference
The stated size of an area doesn't always represent the true amount of surface you are sealing.
A rough, textured or exposed surface has considerably more actual surface area than a perfectly smooth slab.
Examples include:
- Exposed aggregate
- Rough limestone
- Sandstone
- Textured concrete
- Tumbled pavers
- Split-face stone
These surfaces may therefore require more sealer than a smooth or polished surface covering the same number of square metres.
4. Surface Preparation Can Affect Coverage
Correct preparation isn't only important for the performance of your sealer—it can also influence how evenly the product is absorbed.
Dirt, oil, efflorescence, existing coatings and other contaminants can prevent a sealer from penetrating consistently.
Before sealing, the surface should be prepared according to the requirements of the particular product being used.
If an existing coating or incompatible sealer is present, stripping is often required before applying a new product.
Never use additional sealer to compensate for poor surface preparation.
Getting the substrate right first usually provides a more consistent finish and better long-term performance.
5. Different Sealers Have Different Coverage Rates
Not all sealers are designed to be applied at the same rate.
Some penetrating sealers are supplied ready to use, while products such as our Water Based Sealers concentrates are diluted before application.
For example, Pro Seal 896 is supplied as a concentrate and is normally diluted with water before being applied. The diluted product is generally applied at approximately 5–10m² per litre, depending on surface porosity.
Other penetrating sealers may have very different application rates depending on their formulation and the substrate they are designed to protect.
For this reason, always check the coverage information for the specific product rather than using a general sealer coverage figure.
How To Calculate How Much Sealer You Need
Once you know:
1. The total area you need to seal, and
2. The approximate coverage rate of your chosen product
you can make a basic calculation.
The Formula:
Surface Area ÷ Coverage Rate = Litres Required
For example:
If your area is: 80m² and your selected sealer has an estimated coverage of: 8m² per litre the calculation would be: 80 ÷ 8 = 10 litres.
You would therefore require approximately 10 litres of product.
Remember to check whether the coverage figure refers to the product as supplied, diluted or ready to apply, particularly when purchasing concentrated sealers.
Don't Forget About Multiple Coats
The number of coats required can also affect your calculation. Some sealers may require only one saturation or flood coat under suitable conditions, while other products or applications may require additional coats.
If a second coat is required, this does not necessarily mean you will need exactly twice as much product. The first coat can reduce the porosity of the surface, meaning subsequent coats may use considerably less sealer.
Always follow the application instructions for the particular product you are using rather than automatically multiplying the first-coat coverage rate.
Allow A Little Extra
When calculating how much sealer to purchase, it can be sensible to allow a small amount for:
- Variations in surface porosity
- Rough or textured areas
- Application losses
- Edges and difficult-to-reach areas
- Unexpectedly absorbent sections of the surface
It is generally much easier to have a little product remaining than to run out part-way through an application. However, applying more sealer than the surface can absorb is not better. With penetrating sealers in particular, excess product should not simply be left sitting on the surface.
Always follow the application instructions for your selected product.
How To Calculate How Much Sealer You Need
Once you know:
1. The total area you need to seal, and
2. The approximate coverage rate of your chosen product
you can make a basic calculation.
The Formula:
Surface Area ÷ Coverage Rate = Litres Required
For example:
If your area is: 80m²
and your selected sealer has an estimated coverage of: 8m² per litre
the calculation would be: 80 ÷ 8 = 10 litres
You would therefore require approximately 10 litres of product.
Remember to check whether the coverage figure refers to the product as supplied, diluted or ready to apply, particularly when purchasing concentrated sealers.
Don't Forget About Multiple Coats
The number of coats required can also affect your calculation. Some sealers may require only one saturation or flood coat under suitable conditions, while other products or applications may require additional coats.
If a second coat is required, this does not necessarily mean you will need exactly twice as much product. The first coat can reduce the porosity of the surface, meaning subsequent coats may use considerably less sealer.
Always follow the application instructions for the particular product you are using rather than automatically multiplying the first-coat coverage rate.
Allow A Little Extra
When calculating how much sealer to purchase, it can be sensible to allow a small amount for:
- Variations in surface porosity
- Rough or textured areas
- Application losses
- Edges and difficult-to-reach areas
- Unexpectedly absorbent sections of the surface
It is generally much easier to have a little product remaining than to run out part-way through an application. However, applying more sealer than the surface can absorb is not better. With penetrating sealers in particular, excess product should not simply be left sitting on the surface.
Always follow the application instructions for your selected product.
Why You Shouldn't Rely On A Generic Coverage Calculator
A calculator that simply asks for the number of square metres can only provide a rough estimate. For example, 100m² of dense concrete may require substantially less product than 100m² of highly porous limestone.
This is why the better question isn't simply: “How many square metres am I sealing?”. It is: “What am I sealing, how porous is it and which sealer am I using?”
Once those questions are answered, your product requirement can be estimated much more accurately.
Why You Shouldn't Rely On A Generic Coverage Calculator
A calculator that simply asks for the number of square metres can only provide a rough estimate. For example, 100m² of dense concrete may require substantially less product than 100m² of highly porous limestone.
This is why the better question isn't simply: “How many square metres am I sealing?”. It is: “What am I sealing, how porous is it and which sealer am I using?”
Once those questions are answered, your product requirement can be estimated much more accurately.
Not Sure How Much Sealer You Need?
We can help. At WA Sealers, we don't just sell sealing products, we can help you determine the most suitable product for your surface and estimate approximately how much you will need for your project.
Before contacting us, it helps to have the following information available:
- The material you are sealing
- Approximate area in square metres
- Whether the surface is new or existing
- Whether it has previously been sealed
- The finish you would like to achieve
- What is the usage type of the area - a driveway, alfresco, or pool surround all have different priorities in terms of protection and performance
- Photos of the surface if you are unsure what it is
The more we know about your project, the better we can help you choose the right product and quantity.
Need help working out how much sealer you need? Contact Us and tell us about your project.
Not Sure How Much Sealer You Need?
We can help. At WA Sealers, we don't just sell sealing products, we can help you determine the most suitable product for your surface and estimate approximately how much you will need for your project.
Before contacting us, it helps to have the following information available:
- The material you are sealing
- Approximate area in square metres
- Whether the surface is new or existing
- Whether it has previously been sealed
- The finish you would like to achieve
- What is the usage type of the area - a driveway, alfresco, or pool surround all have different priorities in terms of protection and performance
- Photos of the surface if you are unsure what it is
The more we know about your project, the better we can help you choose the right product and quantity.
Need help working out how much sealer you need? Contact Us and tell us about your project.