Bespoke Glass Dual Pitched Rooflight, Skylight and Atrium Designs

The following information has been provided as a general guide on the typically requested products and options within the dual pitched ridged glass rooflight, skylight and atrium range. It is important to note that due to the nature of our bespoke design and build service. You should contact our offices regarding any bespoke requirements outside of those listed and in order to ensure compatibility with the full specification.

Most of the glass rooflight, skylight and atrium options detailed below may also be selected within our standard online budget quote generator (see tab below), which may be accessed by login into an online trade account.

Dual Pitched glass rooflights, skylights and atriums can be provided at almost any dimensions. Rooflight sizes tend to start at 700mm x 700mm due to supporting upstand dimensions and the level difference typically witnessed between the ridged glass rooflight and the ceiling below. Glass ridged rooflights, ridged skylights and ridged atriums can be provided up to 6m spans before additional supporting steelwork/splices will need to be considered. Whilst much larger extents are feasible, the design will need to be developed to incorporate a suitable water management system and facilitate maintenance and cleaning.

Dual Pitched glass skylights, rooflights and atriums can be designed to accommodate any pitch above 5 degrees. However it is worth noting that regardless of rooflight pitch you will normally experience some form of water retention on the glass (e.g. the small water beads that you will find ‘clinging’ to your steep pitch car windows after a downpour). This is due to the gravitational force on the beads (proportional to their mass) being less than the frictional force retaining the water to the glass rooflight. These beads therefore increase exponentially with a reduction in roof light pitch. Although unnoticeable through the steeper pitch applications, these become more apparent (up to approx. 20 - 30mm dia.) over shallower rooflight pitches. Dual Pitched Rooflights, skylights and glass atriums supplied within a modern day patent glazing system must be installed to at least 15 degrees pitch. This is the pitch at which the patent glazed rooflights internal weep system operates effectively, without the risk of capillary and pressure equalisation issues. A dual pitched ridged rooflight/atriums pitch will also have a bearing on the required structural splicing detail about the rooflights ridge line.

Weathered Upstands

Weathered upstand interfaces are most common in dual pitched glass rooflight, skylight and atrium designs. The detail consists of the ridged glass rooflight framework flashing over a weather upstand, wall or guttering detail and this detail therefore always applies to the leading edges of a ridged glass rooflight (for rain water drainage). Some glass rooflight applications can utilise an upstand as small as 100mm above the roof finishes below. However 150mm upstands are typical of flat roof applications (to BS standards).

Wall Abutment Details

Dual pitched glass rooflight, skylight and atrium designs may also utilise wall abutment details to the ends only. In this instance the glass rooflight frame produces a soaker detail (an upstand) above the rooflight level for flashing over by others (typically in lead). Whilst the detail is commonly utilised on wall abutment details, a similar detail may be utilised to recess a glass rooflight into a perimeter upstand detail (i.e. such detail does not have to abut a wall). 

Frameless Glazing

Frameless Glazing (or near frameless glazing) may be utilsed within bespoke dual pitched ridged glass rooflight, skylight and atrium designs. Such designs will always consist of a perimeter frame to complete and weather the rooflight; however such frames can easily be concealed by the internal finishes below. Should your ridged glass rooflight/skylight application be relatively small, the rooflight may be able to be supplied in just 2 No. glass units, with no supporting ridge section. Long, smaller span glass rooflight and atrium applications may also be provide with no supporting ridge. With the ridge glass to glass joints consisting of a flush silicone seal both internally and externally. Larger dual pitched glass rooflight/atrium applications can include 48mm(w) structural glass fins with no additional support or 25.5mm structural glass fins with additional stainless steel glass fittings and brackets. All frameless ridged glass rooflight designs will produce a complete flush silicone jointed external finish.

Structural Glazing

Structural Glazing (or structurally adhered applications) may be utilsed within bespoke dual pitched ridged glass rooflight, skylight and atrium designs. Such designs will always consist of a perimeter frame to complete and weather the rooflight; however such frames can easily be concealed by the internal finishes below. Should your glass ridged rooflight/skylight application be relatively small, the rooflight may be able to be supplied in just 2 No. glass units, with no supporting ridge. Long, smaller span glass rooflight and atrium applications may also be provide with no supporting ridge section. With the ridge glass to glass rooflight joints consisting of a flush silicone seal both internally and externally. All larger applications will require intermediate rafter assemblies which may be provided in a large range of extrusion sections. More frequently glass rooflights are supplied with box section rafters. All structural glass rooflight designs will produce a complete flush silicone jointed external finish.

Framed (Patent) Glazing

Framed Glazing or Patent Glazing may be utilised within bespoke dual pitched glass rooflight, skylight and atrium designs. Such ridged rooflight designs consist of aluminium box section rafter and transom supporting extrusions. The ridged rooflight glass is then retained using EPDM or silicone based gaskets and pressure caps (subsequently concealed by cover/feature caps). Framed glazing systems can heavily rely on a secondary weep water management system, making it imperative that such dual pitched rooflight details are installed in accordance with the systems tested details. Patent glazed ridged rooflights are more recently provided in modern box section rafters, however many dated glass rooflight structures may utilise Victorian style T section rafters. Our company possesses the ability to undertake such refurbishment contracts, where system extrusions need to be developed to meet current building standards whilst retaining the existing glass dual pitched rooflight/atriums character and aesthetics.

Our company specialises in the utilisation of architectural metals and glass. The required dual pitched ridged rooflight, skylight or atrium glazing system selected may have some bearing on the system finishes available. We are typically requested to provide:-

Polyester Powder Coated Rooflights, Skylights and Atriums

Anodised Aluminium Rooflights, Skylights and Atriums

Brushed (Sometimes Polished) Stainless Steel Rooflights, Skylights and Atriums

Bespoke glass ridged rooflight/atrium system finishes may be reviewed in conjunction with the entire design specification.

Our company also provides structural steelwork when required as an integrated component to the dual pitched glass rooflight, skylights and atrium designs we provide.

Our company is able to supply most of the glass specifications available within today’s market. Typically requested ridged rooflight, skylight and atrium glass specifications include:-

Double Glazed and Triple Glazed Specifications

Standard Low E Specifications (as standard)

High Performance Solar Control Coatings

Body Tinted Glass

Low Iron Glass (omitting the natural green tint)

Sandblasted and Acid Etched Glass

Coloured (typically white) Laminates

Ceramic Screen Printed Glass

Low Maintenance & ‘Self Cleaning’ Coatings

Man Safe and Walk On Rooflight Glass Specifications

If you have any queries regarding the utilisation of any glass specification within a specific dual pitched rooflight application, then please do not hesitate to contact our offices with your enquiry.

There are many considerations when reviewing the glass unit dimensions being supplied to a given glass rooflight, skylight and atrium application. Typically the required glass thickness will increase exponentially with its size, resulting in weight increasing exponentially also. An applications site logistics and the glass handling must also be reviewed and will form part of a dual pitched glass rooflight/atrium’s overall cost. Larger glass unit rooflight applications will require suitable plant equipment (typically a crane) to manoeuvre the glass directly into location.

Glazing Innovations are capable of providing glass units up to 6,000mm x 3,000mm (although not to this extent in glass rooflight, skylight and atrium applications). However our offices should be consulted should your application require large glass units as each application will need to be reviewed carefully.  

Architectural glass ridged rooflight, skylight and atrium suppliers will typically provide you with mid pane (or mid unit) U Values. When reviewing a double glazed application with a 16mm (optimum) cavity...

Low E coatings tend to provide a mid pane U Value of 1.7 W/m sq K or 1.6 W/m sq K with an argon filled cavity.

High performance solar control coatings tend to provide a mid pane U Value of 1.2 W/m sq K or 1.1W/m sq K with an argon filled cavity.

Triple glazed applications may achieve a mid pane U Value of 0.6 W/m sq K.

The overall U Value of a dual pitched/ridged glass rooflight, skylight and atrium application is very much determined by the system details utilised. Well engineered rooflight details that mitigate the extent of the framework retain relatively low U Values. Double glazed ridged rooflight, skylight and atrium designs tend to produce an o/all U Value of 1.4 to 2.2 W/m sq K.

Dead loads, wind loadings, snow loadings, maintenance loadings and uplift forces are all considerations when designing a dual pitched rooflight, skylight or atrium. All site specific forces (especially in adverse locations/conditions) should be provided. Ridged glass rooflight wind loadings, snow loadings and uplift forces are all site specific and unless provided at sales stage the averages figures below will be utilised.

UK wind loadings tend to vary from 0.53 KN/m sq to 3.4 KN/m with a typical average of approx. 1.0 KN/m sq to 1.5 KN/m sq.

Snow loadings will also vary depending on your dual-pitched rooflight application. Applications with surrounding walls and roofs above will have much higher potential loadings and snow loadings are normally not applicable for ridged glass rooflight pitches over 60 degrees. UK snow loadings tend to range between 0.6 KN/m sq to 2.0 KN/m sq with a typical average of 0.75 KN/m sq. When combined with maintenance loadings a live load figure of 1.5 KN/m sq is often utilised.

Uplift is rarely an issue (due to it acting against the dead load of the rooflight), however should always be considered. Some applications such as glass ridged rooflights/atriums above large stair wells may have very high uplift requirements.

The dual pitched rooflights/atriums upstands must also be designed to take any thrust forces imposed onto the upstands as a result of the ridged glass rooflights, skylights or atriums design. Sometimes tension bars may be utilsed across the dual pitched rooflights opening to mitigate such forces,

Typically requested glass rooflight, skylight and atrium inclusions are:-

Hipped, Gabled and Tiled Roof Interfacing Ends

Finials

Chandelier Supporting Ridge Details

Rooflight Eaves Guttering

Trickle or Forced Ventilation

Integrated Roof Vents (both manual or electric)

Integrated Blinds

Stepped Edge Glass Units

Low Maintenance Glass Coatings

Man safe and Walk On Glass Specifications.

It is imperative that contract programmes are confirmed via formal quotation issue and/or at the time of order placement. Dual pitched glass rooflights, skylights and atriums programmes vary depending upon size and production requirements. However are typically on an o/all programme (prior to site installation) of 8 to 16 weeks. This programme includes for the preparation of bespoke general arrangement drawings, however does not include for the associated approval period of such.