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7 common mistakes when choosing and installing sandwich panels
Last reviewed:
Short answer
The most common mistakes are choosing a thickness or core that does not suit the building, exceeding the manufacturer's purlin spacing, using screws without sealing washers, cutting with an abrasive grinder, leaving the protective film in the sun, skipping sealant at laps and storing panels on the ground uncovered.
The mistakes and how to avoid them
- Wrong thickness or core: define the required indoor temperature first, then choose thickness and core
- Purlins too far apart: spacing must not exceed the manufacturer's span table for that thickness and load
- Screws without washers: use self-drilling screws with EPDM washers, and do not over-tighten until the washer is crushed
- Cutting with a grinder: hot sparks burn the coating and start rust. Use a saw or nibbler
- Protective film: remove it right after installation; left in the sun it bonds and becomes hard to remove
- Laps: apply sealant at side and end laps, and fit ridge caps and gutters correctly
- Storage: keep panels raised, slightly inclined and covered, and lift them by the edges, not the face
Minimum roof slope and fixing method are set by the manufacturer for each panel type; check the product catalogue before installation.
FAQ
How many screws per square metre?
It depends on span, load and wind zone. The manufacturer sets screws per purlin, with more at edges and corners.
General guidance — not an offer or commitment by BUILDORA.