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.

  • 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.

Glazing Light transmission (LT%) Solar heat gain factor (g%) Thermal transmission (W/m2K)*
Single Clear 88% 83% 5.36
Single Opal Diffused 58% 60% 5.36
Single HeatReflect 56% 46% 5.36
Double Clear 76% 67% 2.95
Double Opal Diffused 53% 49% 2.95
Double HeatReflect 49% 38% 2.95
Triple Clear 66% 55% 2.03
Triple Opal Diffused 46% 40% 2.03
Triple HeatReflect 46% 40% 2.03
Multiwall 16mm Clear 59% 58% 1.88
Multiwall 16mm Opal Diffused 51% 52% 1.88
Multiwall 25mm Clear 57% 65% 1.51
Multiwall 25mm Opal Diffused 49% 54% 1.51
Aerogel 16mm 63% 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.
For more information on Em-Curbs, visit Em-Curb upstands



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.

For more detailed information on each of the available ventilation types, visit Em-Dome Ventilation



Fire rating to BS 476: Part 3 AA
Fire rating to BS 476: Part 7 Class 1 (Class 0 for Building Regulation purposes)
Fire rating to 1991 Building Regulations Tp(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, see Guarantees or contact us.


Installation Instructions

We recommend using out installation service for our more complex continuous and bespoke products; please enquire for more details on this.
Please download the Em-Vault Installation installation booklet for information on how to install your Em-Vault


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.

Contact us and
request brochure