em.vault Barrel Vault

em.vaults are high quality continuous barrel vault rooflights designed to maximise natural light.
These flat roof windows are suitable for flat roofs including single ply, felt, hot-melt, asphalt, liquid, GRP and lead, em.vaults can span widths up to 6m wide and unlimited length.  em.vault purpose made continuous rooflights come in a wide range of profiles and glazing options to meet virtually any specifier and client requirement.  em.vault skylights are also deemed a non-fragile rooflight in accordance with (HSE) Health and Safety in Roofworks.

Product info

Key Benefits:

  • Available in unlimited length
  • Polycarbonate glazing
  • Glazed or solid vertical end panel
  • uPVC upstand curb
  • Perimeter cill section

Profiles and sizes


The standard rooflight profile is a rise 1/6 of the width although a higher rise and bespoke profiles are also available on certain sizes.

  • High-rise (1/2 width)
  • Low-rise (1/6 width)
  • Low-rise (bespoke)

em.vaults are purpose-made and available in widths from 0.6m (Multiwall 1.5m) to 6.0m and in unlimited length.


Thermoformed glazing

em.vaults are constructed from polycarbonate sheet and are available in single, double and triple skin solid polycarbonate and in multiwall construction.  Polycarbonate is virtually unbreakable, with an impact strength up to 250 times greater than glass.  Aerogel is a multiwall polycarbonate filled with translucent aerogel granules, giving an even spread of diffused light and excellent thermal properties.

Available options:
  • Polycarbonate Single skin
  • Polycarbonate Double skin
  • Polycarbonate Triple skin
  • Polycarbonate Multiwall 16mm glazing – Clear or Opal Diffused
  • Polycarbonate Multiwall 25mm glazing – Clear or Opal Diffused
  • Polycarbonate Aerogel 16mm glazing

Barrel vaults are also available with GRP glazing – our T-Vault range. Click here for more details.


em.vault continuous rooflights can be supplied in Clear, Opal Diffused, Bronze or HeatReflect (which reflects up to 68% of the heat radiation) glazing.

  • Clear
  • Opal Diffused
  • Bronze
  • HeatReflect
Glazing Specification Table

All polycarbonate em.vaults have a minimum 3mm thick glazing.  Inner skin thickness varies may vary.

GlazingLight transmission (LT%)Solar heat gain factor (g%)Thermal transmission (W/m2K)*
Single Clear88%83%5.36
Single Opal Diffused58%60%5.36
Single HeatReflect56%46%5.36
Double Clear76%67%2.95
Double Opal Diffused53%49%2.95
Double HeatReflect49%38%2.95
Triple Clear66%55%2.03
Triple Opal Diffused46%40%2.03
Triple HeatReflect46%40%2.03
Multiwall 16mm Clear59%58%1.88
Multiwall 16mm Opal Diffused51%52%1.88
Multiwall 25mm Clear57%65%1.51
Multiwall 25mm Opal Diffused49%54%1.51
Aerogel 16mm63%65%1.4

*Thermal transmission refers to U-Values.  For Ud-Values, please contact us.


em.vault barrel skylights are normally specified to fit to a site formed builder’s upstand although they can, subject to loading calculations, be supplied with the em.curb uPVC range of upstands.

  • Builder’s Upstand
  • em.collar with em.curb ECO uPVC 150mm Vertical
  • em.curb ECO uPVC 300mm Splayed
  • em.curb ECO uPVC 350mm Oversleeve Splayed

For wide and multiwall em.vault units, we would recommend that a builder’s upstand is formed, rather than a proprietary uPVC curb.


All em.vaults have fixed glazing as standard.  However, the options listed below can be incorporated in most permutations of em.vault installations.

  • Permanent Trickle
  • Controllable Trickle
  • Rotating Trickle
  • Controllable Rotating
  • Hinged Manual Spindle Opening
  • Hinged Electric Spindle Opening
  • Powered Ventilation – can be incorporated in the vertical end panels, depending on the available height.
  • Smoke Ventilation – em.vaults with sections opening for smoke ventilation is known as our Es-Vault range – please contact us for more information.


Fire rating to BS 476: Part 3AA
Fire rating to BS 476: Part 7Class 1 (Class 0 for Building Regulation purposes)
Fire rating to 1991 Building RegulationsTp(a)
Service temperature-50°C to 120°C


em.vaults have been tested with Vertical and Horizontal forces to enable reliable performance.


em.vaults use polycarbonate glazing and may be independently tested and certified according to EN 14963: 2006: 1200 Joules, and ACR(M): 001: 2005 Class B and be deemed non-fragile in accordance with (HSE) Health and Safety in Roofworks.

All em.vault barrel vault rooflights are guaranteed for a period of ten years.  For further information, extended guarantees, or specific project guarantees, contact us.

Operation & Maintenance

Whitesales skylights and rooflights can generally be regarded as ‘maintenance free’. However, the following guidelines should be followed to optimize their usefulness. Any maintenance of rooflights must of course be carried out strictly in accordance with the relevant ‘Health and Safety’ regulations.


em.vaults are fixed at installation stage to the relevant upstand, and are a means of allowing natural light into the area below. Polycarbonate rooflights are available as ‘Non-Fragile’, but should not be trafficked.
Wash only with warm soapy water. DO NOT USE strong detergents or abrasives. Physically check Barrel Vaults annually to ensure fixings are secure.


Electrically operated ventilation is operated by means of 24V DC or 240V AC electric actuators.  Electric actuators must be installed by a qualified electrician.  Test annually by an Approved Electrical Installations Testing Company.  Physically check fixing brackets to ensure fixings are secure.

Extract fans

These are fitted to the relevant skylight component and connected to an unswitched Fused-Spur.  A switched electrical supply should be connected by a qualified electrician.  Test annually by an Approved Electrical Installations Testing Company.

For more detailed Operation & Maintenance manuals, visit our Download area.

Case Studies

Looking for inspiration? Take a look over our case studies for this product, view them all using the link below or browse our project gallery for more inspiration.

Find out more

Would you like further information? We are here to help. Send us an enquiry with your project details. Direct purchases can be made through our national network of building and roofing merchants. Use our ‘find a merchant’ resource to find a branch in your area.