Pro Tip: Sealer Surface Dryness Test | Western Interlock
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Paving Stone and Retaining Wall Systems Made for the Northwest

Pro Tip: Sealer Surface Dryness Test

Sealer dryness test dry enough to seal

There are three big mistakes that people make when applying sealer to pavers.

  1. The surface is too hot
  2. The surface is not dry
  3. The surface is not clean

Temperature and cleanliness are pretty easy to understand, but how in the world do you tell if your stones are dry enough? Most sealer manufacturers recommend waiting 24 hours before sealing, and we recommend waiting 72 hours just to make sure, but what if it’s been hot and dry or cloudy and cold? Since the moisture tends to linger in the sand joints which you can’t see down into, how can you really be sure?

The Vapor Barrier Test

After waiting the manufacturer’s recommended 24 hours, an easy way to be sure that the surface and sand joints are completely dry is to create a sort of miniature greenhouse over a small test area by taping down a small sheet of clear plastic. The plastic forms a natural greenhouse which warms the surface in the sun. Any moisture that evaporates from the additional warmth will be trapped inside the vapor barrier. If you tape down a sheet of plastic and leave it for at least 45 minutes in the sun, and you have no moisture on the plastic, your pavers are dry enough to seal.

Camino Stone Small Rec sealer dryness test

These stones have been baking in the sun a while and look pretty dry. But are they really?

Camino Stone Small Rec sealer dryness test

After 45 minutes, the Vapor Barrier Test reveals trapped moisture in the sand joints.

We went back a while later and taped down a new sheet of plastic. After 45 minutes, there was no visible moisture on the plastic. Our stones are now dry enough to be sealed.


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