How long does sealer need before rain can fall on it?

How long a fresh coat needs before rain is answered four ways by four documents, each written for its own products or its own surface.

SEK-Surebond's TB17 gives the reason the window exists: “If the surface was wet to begin with or rain occurs too soon after application, the surface can become cloudy or blotchy.” What that involves from there is answered at what happens when rain hits freshly sealed pavers.

Its SB-1300 sheet frames the span as drying rather than hours: protect the surface “from dust, rain, condensation and traffic while drying,” and cease work in inclement weather, rain or strong wind. The same sheet says low surface or air temperature and high relative humidity extend dry times. Where polymeric sand shares the job, it runs on its own clock: PolySweep is “completely cured when the sand has dried and the joint is hard,” which SEK-Surebond says depends on temperature and humidity and could take up to 24 hours or longer. That cure time is a later point than dry to the touch, and the joint side of the job is defined under joint stabilization.

Three of the four lines are read before work starts: Techniseal's 24 hour forecast, the concrete guide's expected rain, and Seal 'n Lock's near forecast, which carries no hour figure. SEK-Surebond's TB17 also plans for the shower nobody forecast: “a large tarp can be placed on the surface to attempt to keep it dry,” and then removed. That is the maker's contingency for its own products, and its own word is attempt.

The wider question of when the wet season itself makes that forecast check harder to pass is answered at sealing pavers during the rainy season. Whether cars need to move off the driveway for the work, separate from the rain window entirely, is covered at moving cars for a paver sealing.