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Quick Guide to Products
Which system to use?

Unheated Spaces, canopies, station and platform glazing SkyGard should be your first choice if using 6 to 7mm thick glass. If considering different glass thickness, then PlasGard would be your next choice

Heated Spaces
ThermGard is our thermally broken system providing excellent Uvalues and air-tightness when combined with insulating double glazed units for compliance with Building Regulations Part L.

Self-supporting Lanterns or SkyLights
SpanGard self-supporting rooflights feature extruded cill, ridge & hip members to provide you with a complete kit pre-fabricated upto 6m wide by infinite length without the need for additional support, other than a load-bearing curb.

If using Polycarbonate
PlasGard offers a range of glazing bars & accessories for use with ‘plastic’ glazing materials for unheated spaces. If you require a thermally broken system, then please see our ThermGard ALM500 Series

Rafter Glazing
If fitting glazing bars on top of continuous timber rafters, then section reference ALM100/WF suitable for single or double glazing from our ThermGard range, provides neat, low-profile appearance combined with excellent weather tightness and low-maintenance.

Need ventilation?
GlazaTherm roof vents can be incorporated in sloped glazing and fitted with manual, electric or smoke actuators. Alternatively we can provide casement vents in the upstands of lantern lights when required.
Consult the experts
Tel: +44(0)208 801 4221
Bomb-blast Mitigation
Safety Condensation
Glass Types Fire
Glazing Bar Centres Cleaning & Maintenance
Glazing Bar Spans CDM Non-Fragility
Structural Considerations Energy & Environment
Structural Tolerances Design Life Durability
Marine Environment  


Corrosion Resistance of Lonsdale systems in a Marine Environment

‘Marine Environment’ is defined as anywhere within 6 miles of the Sea as windborne seawater can regularly travel this distance.

Aluminium alloy 6063 from which our systems are extruded, is extremely resistant to corrosion due to the surface of the aluminium oxidising and sealing the metal from further deterioration.

It is a common misconception that salt water corrodes aluminium, but if ‘marine grade’ aluminium alloys are employed, salt water remains harmless.

The problem however is due to the process of bi-metallic corrosion between dis-similar metals. Salt water is an excellent electrolyte and speeds up the process resulting in the aluminium corroding quicker than would usually be expected.

This happens over a number of years, but it remains important to isolate dis-similar metals and use only stainless-steel fasteners. Lonsdale provides suitable rubber isolators that fit between our fixing shoes and the steel structure and further protection can be achieved with polyester powder coating.

If the following precautions are observed, a 35-40 year design life can be anticipated:

  1. Only use ‘marine grade’ alloys 6061 or 6063 this applies alloys to any flashings, bracketry or accessories.
  2. Isolate contact with dis-similar metals
  3. When economically possible, powder coat all aluminium with 60 micron polyester powder coated finish and observe manufacturers cleaning & maintenance programme.
  4. Avoid unusually high stresses or surface damage which may amplify corrosion.