Why Proper Detailing Matters at Metal Panel-to-Masonry Transitions

In most commercial buildings you will see a variety of different materials on the exterior to serve different structural, functional and aesthetic requirements. It is common to have Metal Panels and Masonry due to the benefits both can offer. Where these materials meet though you need to carefully plan and install them correctly. Due to the varying movement, thickness, moisture and fixing requirements of the two materials problems can occur. Taking these into consideration will help protect against moisture ingress, damage and expensive repairs.

Managing Different Movement

Metal Panels will expand and contract when temperatures change outside. Masonry will not move to the same degree as the metal and will have different thermal movement. If there is not enough movement allowed then this can cause stress to the joint. This can cause the sealant to come away, warping and cracking can occur. The correct detailing will take into consideration the metal movement and ensure joints are incorporated to allow movement of the panels and correct fixings.

Joints should be spaced and sized depending on the size of the panels, masonry and environmental conditions. Rigid fixings can cause extra stress to the joint. Contractors should follow manufacturers guidelines and project specification to ensure the correct width of joints are being used. Joints should also have the correct backer and flexible fixings. Planning the joints will help to ensure the integrity of the joint.

Preventing Water Infiltration

One of the key aspects of insulated wall panels to masonry joints is managing the moisture. If the joints are not properly sealed, gaps can occur around the flashing or termination. This can cause moisture to get into hidden areas of the building. This can cause issues such as affecting the insulation, infill and internal finishes. Masonry can also hold onto moisture.

Correct details will ensure there is a continuous drainage system. Flashing should be used to divert moisture away from the joint. Contractors should also think about the water resistive layer behind the metal panels and how this connects to the masonry. They should not be separate but should work together. Ensuring correct overlaps, sealed holes and drainage holes will help to avoid moisture getting trapped.

Maintaining Compatible Connection Systems

As metal panels and masonry have different properties they will need different fixings. Metal cladding will be fixed using clips, brackets, girts or hidden fixings. Masonry will have anchors, ties and infill. The transition joint should allow for the fixings to be incorporated without causing an unstable and rigid joint. If the fixings are not well planned then this can cause the materials to become loose. This can cause extra loading on the joint causing damage.

Before installation contractors should plan out what fixings will be going into the joint. The weight of the materials should be taken into consideration along with wind loading and the strength of the infill. Fixings should be compatible to reduce the chance of galvanic corrosion. Planning the correct fixings will help to avoid any changes in the field.

Improving Thermal Performance

If the insulation and air barrier are not properly coordinated then gaps can occur in the thermal protection. As the thickness of the walls can vary there can be little areas where there is not even insulation. This can cause thermal bridging, heat loss and unwanted temperature changes. If the joint is not well insulated then over time this can cause increased heating and cooling requirements.

With correct detailing there will be continuity in the insulation. Designers should consider how the insulation will finish, overlap and connect. This will help to reduce any exposed structural items. The air barrier should also be considered. Small gaps can cause conditioned air to escape and outdoor air to penetrate the building. Using the correct sealants, transition membranes and compatible closings will help to keep the thermal performance of the building.

Improving Installation Accuracy

Even with correct detailing if the contractors do not follow the details correctly then problems can occur. As masonry can be uneven, panels can be out of position, substrates can vary and joints can vary in size it can be difficult to install the joint correctly. If problems are found late in the project this can cause the panels to be cut differently, flashing changes and adjustments to the infill. This can cause extra labour time.

By considering the details beforehand problems can be identified. Contractors should know what gaps are required, where fixings go and what order they should be installed in. Before panels and finishes are manufactured measurements should be taken and compared to the build drawings. This will help improve installation accuracy.

Conclusion

Correct detailing of metal panels to masonry joints will help to improve longevity, moisture protection and energy efficiency. Taking into consideration movement, drainage, fixings and insulation will help to avoid any issues. By coordinating with the designers the installation will be more accurate. By properly considering the joints the project team can create reliable and functional external joints.