Repair Systems — 03 — Facade & External Envelope
Storm angle — aluminium
Technical product reference for extruded aluminium storm angle systems used in window and door frame remediation on Australian Class 2 strata buildings. Covers standard extruded aluminium storm angles and cover angles for head, jamb and sill applications — used to provide a secondary weather barrier at the frame-to-wall interface and redirect water away from the perimeter joint.
What are aluminium storm angle systems for windows?
Aluminium storm angles (also called cover angles or cover beads) are metal angle sections fixed at the perimeter of window and door frames to provide a secondary weather barrier at the frame-to-wall interface. They are installed over the top of the primary perimeter sealant and are used where the perimeter joint is persistently failing or where the building exposure requires a more robust weatherproofing detail than sealant alone.
Product Reference
3 products — aluminium storm angle systems — scroll to view all
Extruded aluminium storm angle — standard 50×50×3mm
Extruded aluminium equal angle — window storm angle
System Description
Standard 50×50×3mm extruded aluminium equal angle sections are cut to length and used as storm angles (cover angles) at window head, jamb and sill locations to provide a secondary weather barrier at the frame-to-wall interface. The angle is fixed to the masonry or frame with 316 stainless screws, the top and end joints sealed with a compatible neutral cure silicone or PU sealant, and the angle can be powder-coated or anodised to match the facade or window frame colour. Aluminium storm angles are appropriate for non-coastal and low-to-moderate exposure environments — specify stainless 316 angles for coastal and marine-influenced locations. All fixings must be 316 stainless. Confirm that the 50×50mm leg dimensions accommodate the specific window frame and wall reveal geometry. Other angle sizes (40×40, 50×25, 75×50 etc.) are available for different applications — confirm dimensions required before ordering.
Technical Properties
- 50×50×3mm extruded aluminium equal angle — standard ex-stock section
- Anodised or powder-coated finish — confirm colour match with frame or facade before ordering
- Cut to length from standard 6m bar stock — simple site or workshop operation
Limitations
- Not suitable for coastal environments within approx. 1 km of the ocean — specify stainless 316 angles instead
- Aluminium does not render well without surface preparation — key or coat the surface before rendering over
- All fixings must be 316 stainless — do not use carbon steel or zinc-plated fasteners with aluminium
PROCUREMENT SOURCES
Confirm dimensions, finish and coastal suitability before ordering.
Extruded aluminium storm angle — unequal leg 75×50×3mm
Extruded aluminium unequal angle — wider coverage storm angle
System Description
75×50×3mm or similar unequal leg extruded aluminium angles are used where the standard 50×50 equal angle does not provide sufficient coverage over the window frame or where the wall reveal depth requires a longer horizontal leg. The longer horizontal leg (75mm) laps further over the frame or render return, providing improved water shedding coverage. Fixed with 316 stainless screws, top and end joints sealed with compatible sealant. Anodised or powder-coated finish to suit the project. Confirm the specific leg dimensions required for the project before ordering — unequal angles in specific sizes may require ordering from a distributor rather than being available as ex-stock. All fixings must be 316 stainless. Suitable for non-coastal, low-to-moderate exposure environments. Specify stainless 316 angles for coastal locations. TODO: owner confirm — confirm appropriate leg dimensions for the specific window reveal and frame geometry.
Technical Properties
- Unequal leg aluminium angle — longer horizontal leg for increased coverage
- 75×50mm or similar dimensions — confirm specific size required for each project
- Anodised or powder-coated finish — confirm colour match before ordering
Limitations
- Not suitable for coastal environments — specify stainless 316 unequal angles for coastal locations
- Specific unequal sizes may require ordering (not ex-stock) — confirm availability and lead time
- All fixings must be 316 stainless — no carbon steel or zinc-plated fasteners
PROCUREMENT SOURCES
Confirm dimensions, finish and coastal suitability before ordering.
Proprietary aluminium cover angle / storm bead profile
Proprietary aluminium storm angle / cover bead
System Description
Proprietary aluminium cover angle and storm bead profiles are purpose-designed extruded profiles for window storm angle applications. Unlike standard angle sections, proprietary profiles may include integral features such as a drip groove on the underside of the horizontal leg (to prevent water tracking back under the angle), a sealant recess channel on the back leg, or a pre-formed nose profile. These purpose-designed features improve the weatherproofing performance of the storm angle system. Available from flashings and building hardware suppliers — confirm specific product, profile dimensions and Australian availability with the supplier. All fixings must be 316 stainless. Confirm whether the specific proprietary profile is suitable for coastal or high-exposure environments — most aluminium profiles are not suitable for coastal locations. TODO: owner confirm — confirm specific proprietary profile, Australian availability and coastal suitability before specifying.
Technical Properties
- Purpose-designed extrusion — may include integral drip groove, sealant channel or nose profile
- Better weatherproofing performance than standard angle section in some configurations
- Available from flashings and building products suppliers
Limitations
- Product range varies by supplier — confirm specific profile dimensions and availability before specifying
- Generally not suitable for coastal environments without specific corrosion-resistant coating
- Confirm coastal suitability with the specific product manufacturer before specifying for coastal locations
PROCUREMENT SOURCES
Confirm dimensions, finish and coastal suitability before ordering.
System Comparison
Side-by-side comparison of aluminium storm angle systems. Confirm dimensions, finish and coastal suitability before specifying.
| Product system | Type | Material | Finish | Coastal | Supply | Primary use |
|---|---|---|---|---|---|---|
| Extruded alum. 50×50×3mm equal angle | Equal angle | Alum. extrusion | Anodised / PC | No | Ex-stock | Standard window storm angle at head, jamb or sill — most common specification |
| Extruded alum. 75×50×3mm unequal angle | Unequal angle | Alum. extrusion | Anodised / PC | No | Order req. | Wider coverage where standard 50×50 angle is insufficient for the reveal depth |
| Proprietary cover angle / storm bead | Proprietary | Alum. extrusion | Powder coat | Confirm | Supplier stock | Purpose-designed profiles with integral features — confirm AU availability |
Critical notes for aluminium storm angle specification and installation:
- Storm angles are a secondary weatherproofing measure only — they do not replace correctly installed and sealed primary perimeter joints; the primary sealant joint must be installed correctly first
- Aluminium storm angles are suitable for non-coastal and low-to-moderate exposure environments — specify stainless 316 angles for coastal, marine or high-exposure locations
- All storm angle fixings must be 316 stainless or anodised aluminium — do not use carbon steel or zinc-plated fasteners with aluminium in exterior applications
- Storm angles must be sealed at top, sides and all penetrations with a compatible sealant — unsealed angles collect water at junctions and worsen perimeter leakage
- Do not render over aluminium angles without confirming render adhesion — standard cement render may not bond adequately to bare aluminium; key or coat the aluminium surface before rendering
- Confirm powder coat colour match with the window frame or facade colour scheme before ordering — ex-stock angles are typically mill (silver) or white finish
Disclaimer
This page provides general technical information only. Storm angle sizing, fixing details and sealant specification must be confirmed by a qualified remedial practitioner against site conditions and exposure classification. Storm angles are a supplementary weather barrier — not a substitute for correctly installed perimeter sealant.