Most HPL problems in the field are installation failures, not material failures. Panels bow, joints open and water gets behind the cladding because of a handful of avoidable errors. Here are the seven that cause the most damage.
1. No Expansion Gaps
HPL expands and contracts with temperature. On an Indian facade, surface temperature can swing more than 30 degrees between a summer afternoon and a winter night. If panels are butted tight against each other or fixed rigidly at every point, that movement has nowhere to go, and the panel bows or the fixing point cracks.
Expansion gaps must be designed in at panel edges and around fixings, and they must be maintained during installation rather than closed up for a neater look.
2. Wrong Fastener Type
Fixings need to allow slight movement, not clamp the panel rigidly. Over-tightened screws or the wrong rivet type create a fixed point that the panel then fights against as it expands. Fastener holes in the panel should be slightly oversized to permit that movement.
Using non-corrosion-resistant fasteners is a second version of this mistake. Rust streaking down a new facade is entirely avoidable.
3. Inadequate Framework Spacing
A 6mm panel spanning too far between framework members will deflect visibly, especially in direct sun. Framework spacing must match the panel thickness and size. Around 600mm centres is a common starting point for 6mm panels, but this depends on panel size and wind exposure.
Cutting framework costs by widening spacing is a false economy that shows up as a wavy facade.
4. Blocking the Ventilated Cavity
The air gap behind the panels is functional, not incidental. It allows any water that gets past a joint to drain out and lets moisture evaporate. If installers fill the cavity with insulation without provision for drainage, or seal the bottom of the cavity closed, water accumulates against the wall.
The base of the cavity must stay open, protected against vermin but not sealed.
5. Unsealed Cut Edges
The panel face is sealed by the overlay; a freshly cut edge is not. On horizontal bottom edges especially, water sits against exposed core. Sealing cut edges is a small step at installation that prevents a slow problem years later.
6. Poor Substructure Material Choice
The framework outlasts nothing if it corrodes. Untreated MS sections in a coastal or high-humidity location will rust, and as they do, the cladding above them loses its fixing integrity. Match framework material to exposure: galvanised or aluminium in aggressive environments.
7. Mixing Production Batches
Ordering short and topping up later risks a slight shade variation between batches. On a large elevation this can be visible as a colour band. Order the full quantity including wastage in a single consignment, and if panels do come from different batches, plan the layout so any variation falls at a natural break rather than mid-wall.
Before Installation Starts: A Short Checklist
- Confirm framework material and spacing against panel thickness and wind load
- Confirm fastener type, hole size and torque approach
- Confirm expansion gap dimensions and joint detailing
- Confirm cavity drainage at the base is open
- Confirm all panels are from one batch and stored flat, off the ground, out of direct sun
- Dry-lay a section to check layout before permanent fixing
Frequently Asked Questions
Why is my HPL cladding bowing?
Almost always insufficient expansion allowance, over-tight fixings, or framework spacing too wide for the panel thickness.
How much expansion gap does HPL need?
This depends on panel size and the manufacturer’s specification. Always follow the supplier’s technical guidance rather than a generic figure.
Can I install HPL myself?
Small areas such as a gate panel are feasible for a skilled DIY approach. Full facades need experienced installers, mainly because framework design and drainage detailing determine long-term performance.
Do cut edges need sealing?
Yes, particularly horizontal bottom edges and any edge where water can sit rather than run off.
Planning an installation? Contact our technical team for framework and detailing guidance specific to your project.