Should my concrete surface be sealed?
A common question asked by homeowners with new/existing driveways, patios and paths is “should it be sealed?” The simple answer is yes – a good sealer protects your investment. There are a few things to consider before jumping in and below we detail some of the benefits of sealing and other considerations that play a part in choosing the correct sealer for the job.
Why should I seal my concrete surface?
In short, a sealer will protect your new or existing drive, patio, path and other concrete surfaces. When properly sealed and/or resealed, the life of the concrete surface is extended. Exterior concrete in areas subject to freeze-thaw cycles should be sealed. In other regions, concrete should be sealed for specific purposes such as stain repellence, dust reduction, abrasion resistance, chemical resistance as well as for cosmetic appeal.
The benefits of sealing (and in particular of using a good quality sealer) includes:
- improved stain resistance
- Aesthetic appearance (curb appeal)
- enhanced colour (if desired) to provide a rich finished look
- protects colour from fading due to UV exposure
- reduces freeze-thaw damage
- prevents efflorescence.
- Easier cleaning (sealed surfaces are generally easier to clean)
What could happen if I don’t seal my concrete area?
Since concrete is, by nature, a porous material it readily absorbs liquids. In freeze-thaw climates, the expansion of frozen liquids can destroy the surface of unsealed concrete (resulting in cracking, spalling, surface flaking and pop outs). Oil, salt, dirt, pet urine, household chemicals and other liquids such as spilt drinks can stain and damage unsealed concrete surfaces.
Types of sealers:
- Concrete densifier – Permacolour’s KS500 can help to increase the strength and density of the concrete thereby decreasing the moisture permeability and porosity of the concrete surface. Permacolour KS500 reduces deterioration caused by surface abrasion and reduces surface dusting. This sealer is invisible and does not enhance the colour or appearance of the concrete surface.
- Concrete water repellent sealer – Permacolour’s Repell SS reduces the absorption of water, waterborne salts, oil, gas, grease and other fluids. Repell SS also reduces water and chloride intrusion and the growth of moss, reduces efflorescence and allows the concrete to breathe. Repell SS is invisible and does not enhance the colour or appearance of the concrete surface.
- Acrylic – Solvent Concrete sealer – Permacolour has a range of Acrylic-solvent sealers which provide a wet-look finish and aid in reducing staining. They are generally gloss in appearance, however, a matting agent can be added to reduce the gloss factor. Permacolour’s standard Concrete Sealer is UV resistant, offers a high resistance to acid, oil, grease and mildew as well as from stains from organic matter. It seals and dustproofs the surface while providing resistance to water,tyre-marking and scratching. Permacolour offers a wide range of Acrylic-Solvent sealers with varying properties, info of which can be found below.
Note: The use of both Permacolour’s KS500 densifier and Permacolour Repell SS is common and provides enhanced protection, with a natural look. The KS500 is applied first, followed by Repell SS 4-5 days later.
Permacolour Concrete Sealer is a great option for sealing your driveway, patio or footpath. It offers great stain protection, is UV stable and is also affordable.
What will the final look of the sealed surface be?
This depends on the type of sealer used and there are a few considerations to take into account when selecting the right sealer for your job.
Sealers have different functions and properties – so the choice of sealer is usually determined by your requirements (in terms of function, protection/durability, appearance, internal/external use, colour enhancement/wet-look, natural look etc).
All new concrete surfaces (except exposed aggregate surfaces) must be acid washed prior to sealing, in order to open up the pores – this allows for better penetration and grip of the sealer. When resealing only clean with Permacolour Concrete Cleaner – do not acid wash or water blast sealed surfaces prior to re-sealing.
Prices vary with many different options available.
Like all things in life, (your car, your home) maintenance is required. Your external concrete surfaces are no different.
A good wash with Permacolour Concrete Cleaner and some water will do the job to correctly clean the surface as part of regular maintenance on the surface, as well as prior to any resealing.
How often should my concrete surface be resealed?
Resealing every few years is recommended to maintain the protection and aesthetic of the concrete surface. The expected lifespan of a sealer is determined by a few factors:
- Type of Sealer used
- Traffic to the area
With Acrylic Solvents, like Permacolour Concrete Sealer, re-sealing may be necessary after 2 years in heavy traffic areas. In instances where there has been less traffic/weathering a reseal every 3-5 years is required.
How long should I wait before sealing?
The recommended curing time for new concrete is 28 days before sealing. It is imperative, whether sealing new or existing surfaces, to ensure that the surface is completely dry before sealing.
Yes, adding a sealer can make the surface slippery and smooth trowelled surfaces do have a risk of being slippery even when unsealed. Sponge, broomed or exposed aggregate finishes are the best external finish options to have because it already has a texture.
But what if my external concrete is smooth? There is light at the end of this tunnel. Slip reducers can be added to the sealer or hand broadcast over wet sealer to add a little grip to the surface after first preparing the surface for sealing by acid etching.
Is sealing a DIY job?
Permacolour recommends that sealing be done by trained professionals, simply because they have a greater awareness and skill when it comes to surface preparation and experience with correct sealing practices etc.
Some issues to look out for before/after sealing?
- Blooming/blushing – This is the whitening of the sealer from trapped moisture in the concrete surface. Dependant on the severity, it can be easily treated. This typically happens when the surface has been sealed too soon after the concrete has been poured or after rain, and moisture is still present,
- Flaking – This normally happens for one of two reasons.
- The blooming/blushing of the sealer has been left too long and compromised the bond of the sealer.
- Poor surface preparation and the sealer has failed to penetrate into the surface.
- Measling – This is the darkening of the surface via small open pores or cracks in the concrete when the sealer is applied. This is normally more prevalent after rain causing dark spots on the surface, along grout lines and decorative cuts. Moisture penetrates under the sealer, cannot escape and darkens the surface. The measling normally disappears after a few dry days. Permaolour’s Repell SS is a great way to stop measling.
Contact us to find out what sealer is best for your project or for any technical information.