How are asphalt shingles typically hand-sealed?

Asphalt shingles are typically hand-sealed by applying quarter-sized spots of roofing cement. This method is used to ensure that the edges of the shingles are secured and can prevent wind uplift and water penetration. The quarter-sized spots create a strong, localized bond that holds the shingles together while allowing for some flexibility. This sealing technique also helps to reduce the potential for water to slip under the shingles, which could lead to leaks and damage.

The other options refer to methods that are not standard for hand-sealing asphalt shingles. A full coat of adhesive may be too much and could lead to unintentional pooling or adhesion issues. Using a liquid adhesive could also result in non-uniform application and might not provide the targeted sealing required. Heat bonding is a method more commonly associated with certain types of roofing materials, like modified bitumen, rather than asphalt shingles, which typically rely on the application of roofing cement for sealing.