Gaping is the unwanted parting or opening up of a seam, joint or connection that should actually be tightly closed. The phenomenon usually indicates that a material is moving, shrinking, or that a component has shifted position.
Application
Gaping occurs in many parts of a building, and each case has its own cause:
- In timber joints, gaping arises chiefly from shrinkage and drying out. Fresh or overly damp timber releases moisture, shrinks, and so pulls apart the seams of mortise-and-tenon joints, door panels or floorboards. This is also known as the movement of timber.
- In masonry, gaping shows up as open or cracked joints. This can result from settlement of the foundation, mortar that dried too quickly, or stresses within the wall.
- In sheet materials such as plywood, MDF or plasterboard, gaping appears at the seams when boards shrink, expand, or are not closely butted together.
Gaping seams are not only unsightly but can also have functional consequences: they let moisture, draughts or dirt through and may weaken the connection. To prevent gaping it is wise to work timber at the correct moisture content, allow materials to move freely with expansion joints, and seal seams with sealant, jointing compound or cover battens.
If gaping still occurs, small seams can be filled with wood filler, acrylic sealant or pointing mortar. For larger problems, such as those caused by settlement, it is important to address the underlying cause first.
Related terms
- Bricklaying
- Mortar
- Foundation
- Facade
Learn more about construction terms in our knowledge base on fredsdiyplans.com.