Skalfugning

Skalfugning is a term used in Danish construction to describe the sealing of joints in the exterior shell of a building. Its main purpose is to prevent air leakage and water ingress while accommodating movement in the building envelope, such as between façade elements, around windows and doors, and at expansion joints.

The process involves preparing the joint area (cleaning, drying, and removing old material if needed), selecting an appropriate sealant, possibly inserting a backer rod to control joint depth and movement, applying the sealant with a caulking gun, and tooling the surface for a smooth finish. Curing times depend on the chosen material and environmental conditions.

Materials commonly used for skalfugning include polyurethane-based, silicone-based, and acrylic or MS-polymer sealants. Polyurethane sealants offer strong adhesion and resistance to chemicals; silicone sealants provide high elasticity and durability in exterior exposure; acrylic sealants are typically a cost-effective option for less demanding applications. The choice of sealant should consider movement capability, substrate compatibility, UV exposure, and temperature conditions.

Design and installation considerations include matching the joint width and depth to the sealant’s properties, ensuring proper backer rod sizing, and using primers on porous substrates when required. Dynamic joints should have adequate allowances for movement, typically specified by the sealant manufacturer.

Maintenance is essential; joints should be inspected regularly and replaced when cracking, loss of adhesion, or significant wear occurs. Proper skalfugning contributes to the building’s moisture control, energy efficiency, and long-term durability.