Sealer gets pitched a lot in this industry as the finishing step that locks everything in, and we get asked about it often on polymeric sanding jobs. Our honest answer is that we usually do not recommend it, and this guide explains why.
It is not that a sealer never has a place. It is that most driveways and patios do not need one, and putting one on the wrong job can leave you worse off than if we had just left the surface bare.
We would rather tell you the straightforward version of this before you spend money on it, and then let you decide with the full picture rather than a sales pitch.
Our honest answer, usually not
For most interlock jobs, we do not recommend a sealer. It is an extra cost, an extra step, and on a properly washed and sanded surface it is not doing the job people think it is doing. Water, not sealer, is what actually locks polymeric sand into place, and the wash itself is what brings the colour back to the stone. A sealer is solving a problem that the process has usually already solved, which is why we would rather be upfront about that before you spend money on it.
What actually sets the sand and brings the colour back
Polymeric sand hardens because of water, misted into the joints in light passes once the new sand is packed and level. That is the step that locks the stones together, not a topcoat applied after the fact. Meanwhile, the wash itself strips years of built up dirt, algae and oxidation off the surface of the pavers, which is what actually restores the original colour people are hoping a sealer will add. Both jobs are already done before sealer would even come into the conversation.
Why a sealer can work against you over time
A sealer sits on top of the stone rather than becoming part of it, and over time that layer can start to look greasy or overly glossy in a way that reads as artificial rather than clean. It can also trap moisture underneath it depending on the product and the surface, which is the opposite of what you want on interlock that is exposed to Toronto winters and the freeze and thaw cycles that come with them. None of that is a reason to panic if a sealer is already on your driveway, but it is why we do not add one by default.
When we will still put one on
If you still want a sealer after hearing all of this, that is entirely your call, and we will go over the options with you directly on the visit rather than talking you out of it twice. Some homeowners like the slightly deeper, wet look sealer gives certain stone, and that is a reasonable preference to have. We just want you making that choice with the full picture, not because a sealer was assumed to be part of every job by default.
What we recommend instead
If you are trying to protect your investment and keep the colour looking fresh, the better move is a pressure wash of the surface about once a year, which is covered in more detail in our guide on how long polymeric sand actually lasts. That single step does more for the long term look and life of your joints than a sealer would, without the risk of trapped moisture.
If your driveway is already showing early signs of trouble like weeds or ant activity in the joints, our guide on ants in your interlock pavers covers what that actually means and why sealing over it would not fix the underlying issue.
How this fits with the guarantee
None of this changes what our seasonal guarantee covers. The sanding itself is usually good for 3 to 5 years whether or not a sealer goes on top, since it is the wash, the dry joint and the water misted in that actually does the work of locking it down, not a topcoat. If weeds come through earlier than expected, text us a photo and we come take a look and touch it up at no charge, regardless of whether a sealer is on your property.
So the honest version of our advice is this: skip the sealer, save the cost, wash the surface about once a year, and lean on the guarantee if something does go wrong early. That combination does more for your driveway over time than a sealer ever will on its own.
What we notice when a sealer is already on a property
We come across plenty of interlock that already has a sealer on it from a previous owner or a previous contractor, and it does not stop us from washing and resanding the surface properly. If anything, a sealer that has started to look patchy or discoloured is usually part of what prompted the call in the first place, since it stops looking clean and starts looking like a problem in its own right.
In those cases we treat the wash the same way we would on bare stone, and we will tell you honestly on the visit whether the existing sealer is worth reapplying afterward or whether we would recommend leaving it off going forward, based on the specific stone and how it is holding up.
