There are several types of sealant on the market that adhere to most surfaces, but you must above all base your choice on the application you will make of it. It is important to know if the movement of the wall will be high or low, what is the life cycle of the building and what is the necessary chemical resistance.

	Put a joint support (styrofoam sausage). This technique will ensure you have control over the depth and shape of the joint. It will also provide you with a base for smoothing and will prevent 3-sided adhesion (bond failure).
	Respect the format of the joints according to an approximate rule. The minimum width is ¼ and the maximum width is 3''. If you exceed these dimensions, you will need to install an expansion or control joint instead.
	Apply the smoothing technique with a cat's tongue to have maximum adhesion and give a concave shape to your joint.

The NP1 sealant from Master Builders Solutions is the product we recommend. It is a one-component, primerless, sprayable, high performance polyurethane elastomer. It requires no mixing to adhere to many materials, including concrete and masonry ( adheres to fresh concrete as early as 72 hours after application) .

NP 1 is available in 12 standard colors to match a wide variety of common substrates and is paintable. The seal has a capacity of + or - 35% elasticity and is designed for places with frequent temperature variations. UL listed, it passes the 4-hour, 4-inch fire and water jet test when used with Ultra Block or mineral wool.