Sandwich panels
Services in a sandwich panel home: what to agree before closing the walls
Services in a house with a sandwich panel envelope should be planned alongside room layouts and penetrations through the walls and roof. Later drilling may conflict with the structure, airtightness or finishes. A coordinated plan needs to cover routes, equipment, supports and maintenance access. This guide explains what to give designers and contractors before walls are closed. It concerns coordination, not do-it-yourself electrical, ventilation or fire-protection design. It specifies neither opening diameters nor anchor types. Instead, it shows why a socket, cabinet or appliance position must be considered within the complete wall arrangement. The envelope installer should know the agreed routes and fixing positions before work that modifies the panels begins.
List room equipment
Kitchen, bathroom and plant-room layouts influence service requirements. List fixed appliances and items needing connections. A socket count alone is not an adequate brief.
Include known future equipment changes. The designer can assess suitable provision for them. That does not mean making unapproved openings for possible future use.
Coordinate the service zone
An internal lining may provide space for services, but its depth and construction must be allowed for in room layouts. Consider effects on usable space and window and door positions.
Agree the sequence of envelope installation, services, checks and closing the lining. The lining installer needs to know which sections are ready to be concealed.
Plan envelope penetrations
Mark penetrations on a common drawing with clear wall references. Trades should resolve clashes before openings are made. Separate sketches may allocate the same space to different equipment.
The penetration detail must suit the element’s function and project requirements. Assign responsibility for making the opening and achieving the required performance around it. An external cover alone does not settle these questions.
Identify load-bearing fixings
Identify wall cabinets, water heaters and other heavy items separately. Equipment weight is not the only input needed for fixing design; the load path matters too.
Do not treat a thin steel facing as a universal fixing base. Fixing to a panel or a separate frame requires a suitable detail. The installer needs it before supporting elements are concealed.
Retain maintenance access
Equipment requiring checks must remain accessible as its documentation specifies. Allow for opening covers, changing filters and service access. Finished cabinetry can otherwise obstruct these tasks.
Maintenance access should not depend on improvised cuts through the sealed envelope. Where removable finishes are needed, document their purpose and the intended extent of removal.
Record installed routes
Before concealment, take organised photographs and mark agreed changes on drawings. A photograph without a wall reference or measurement datum may be of limited use later.
Keep services records alongside envelope information. Before later alterations, check existing routes and fixings. A new connection needs assessment even when the wall appears visually empty.
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