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FAQs

This Approved Document, which took effect on 1 October 2010, deals with energy efficiency requirements in the Building Regulations (as amended) and is made up of four distinct publications which are noted below. It should be noted that Approved Documents are guidance publications and there is some provision for trade-off with other building elements – any proposal should be checked with the relevant building control body. U-Values should be calculated in accordance with BRE 2006. The document also covers areas such as Materials and Workmanship including a requirement to demonstrate appropriate use of products with CE marking, British Standards and European Technical Approvals. Whitesales continuous rooflights have undergone stringent and extensive testing and are certified to these standards.

ADL 1A:New dwellings

ADL 1B: Existing dwellings

ADL 2A:New buildings other than dwellings

ADL 2B: Existing buildings other than dwellings

For more detail on the specific U-Value requirements for your project please contact our sales team on 01483 271371. Click here to find out more about the four ADL documents.

Yes, Whitesales polycarbonate Em-Dome rooflights are tested and certified to BS476: Part 7 – ‘Class 1’ (‘Class 0’ for Building Regulation purposes). Approved Document B places certain limitations on the use of rooflights, which are dependent on glazing material and site circumstances, such as building size, use of area below rooflights, rooflight size and proportion of total roof area, distance from boundary, etc. The relevant information is set out in Volume 1: Sections 3 and 10; Volume 2: Sections 6, 12 and 13 of Approved Document B, 2006 Edition.

Where applicable, the responsibility for determining that any building component complies with the relevant Regulations rests solely with the customer or specifier.

Approved Documents L1A and L2A include requirements to limit solar gains through the summer period. The inside of the building can heat up during daylight hours due to the sun. This is termed as solar heat gain. To reduce this effect, solar control glass can be adopted to reflect heat and reduce glare from the sun’s rays. This lessens the burden on air-conditioning systems thus reducing CO2 emissions. In simple form, this may be body tinted glass in blue, green or bronze or more sophisticated, coated clear glass that allows maximum light transmission, but at the same time substantially reduces heat gain.

The Whitesales ‘HeatReflect’ glazing products are greatly beneficial in reducing solar overheating, cutting back the heat rays passing through the glazing whilst still allowing light to pass through.

Yes. The standard Whitesales Em-Curb is made from extruded white PVC. The multi-chambered construction gives an exceptionally robust and thermally efficient performance. This upstand is suitable for most roof finishes, including felt, singly ply membranes, liquid, hot-melt, asphalt (with EML and sheathing), lead, and is available in heights of 150, 300 and 350mm with other heights also available.

All ventilation, access hatch and smoke vent options can be used in conjunction with Em-Curbs.

Em-Curbs can also be supplied in GRP which have integral 10mm polyurethane foam insulation and robust dome fixing and mounting flanges. They can be used with most roofing materials, including apshalt and GRP.

Oversleeving is a concept that enables existing rooflight upstands to be left in place when replacing rooflights. This practice minimises the need to undertake work to the internal lining or reveal, thereby normally removing the need for the roofing contractor to enter the room below the rooflight.

The Em-Curb Oversleeve upstand simply sits around the outside of any existing upstand after removing the existing glazing element.

Of particular note this can be used where existing upstands incorporate and asbestos lining because this can be left undisturbed.

Yes, Whitesales polycarbonate Em-Dome rooflights are tested and certified to BS476: Part 7 – ‘Class 1’ (‘Class 0’ for Building Regulation purposes). Approved Document B places certain limitations on the use of rooflights, which are dependent on glazing material and site circumstances, such as building size, use of area below rooflights, rooflight size and proportion of total roof area, distance from boundary, etc. The relevant information is set out in Volume 1: Sections 3 and 10; Volume 2: Sections 6, 12 and 13 of Approved Document B, 2006 Edition.

Where applicable, the responsibility for determining that any building component complies with the relevant Regulations rests solely with the customer or specifier.

Just as metal rusts, glass is subjected to a corrosion process caused by reactions between the glass surface and environmental pollution. Even a single droplet of moisture on unprotected glass can produce sufficient damage to be visible in good lighting.  The surface of glass is not smooth and consists of microscopic peaks and potholes. Both organic and inorganic contaminants fill these potholes and chemically react with the glass, firmly bonding to the surface. Because of this, cleaning glass becomes more difficult and visibility deteriorates.

Self-clean coatings are a polymeric resin and, when applied to ordinary glass, it cross-links to form a strong chemical bond. It is completely transparent, chemically inert, non-hazardous and UV stable. Unlike a coating, it becomes part of the glass so will not peel, flake or crack.  The result is 'non-stick' glass that prevents contaminants from bonding to the surface and limits further damage caused by corrosion and chemical attack. Dirt can easily be removed using normal cleaning methods.

A non-fragile rooflight is NOT designed to be walked upon. It is designed to save lives by preventing people or objects falling through it accidentally, when accessing roof areas not designed for regular foot traffic. However, a person or other object falling onto a non-fragile rooflight may cause damage to the rooflight, resulting in it becoming fragile. For example, a seemingly minor scratch to the surface of a polycarbonate rooflight may penetrate the UV protecting layer, which in the long term may result in UV damage which can severely affect impact resistance.

Walk-on rooflights are designed to floor loadings and for deliberate foot traffic.  They are generally installed in-plane with the surrounding flooring, to provide a transparent or translucent panel allowing light transmission to internal areas below.

Condensation occurs where warm moist air meets cold surfaces. As warm air rises, the risk of condensation forming at rooflight level is relatively greater than at lower level. The risk can be minimised by specifying triple skin Whitesales rooflights and Em-Curb insulated upstands. The provision of ventilation may also assist. However, because temperature and humidity levels are clearly beyond our control, no guarantee can be given against the formation of condensation.

Condensation between the skins can also occur when the room below has high humidity levels, for example during construction from new plaster or paintwork. Polycarbonate is hygroscopic and allows water molecules to filter through – the water pressure forces its way through the lower skin and condenses inside the cavity. However, once the humidity level in the room is restored to normal this condensation dissipates through the breathable seals.

While all Whitesales products are suitably packaged to avoid damage, care should be exercised when handling. For moving larger items, two or more people may be needed. All products should be stored in flat, dry conditions.

Are access hatches available with internal and external handles?

Whitesales provide two types of access hatch.  Em-Hatch is the apartment and commercial access hatch and is available with internal locking espagnolette handle as standard.  Es-Hatch is the commercial access hatch and is available with internal and external locking as standards.  It is also available as non-locking for ease of access as an escape route.

What size of smoke vent do I need to achieve a free vent area of 1.0m2?

Whitesales have a range of sizes to provide 1.0m2 free vent area.  The Em-Vent S16 1050x1050mm, R7b 700x1600mm, R11 800x1300mm, R16 900x1200mm all achieve 1.0m2 free vent area and are all stock items.  We also offer Es-Vent and Es-Louvre smoke vents in standard sizes to achieve these vent area values.

What size of smoke vent do I need to achieve a free vent area of 1.5m2?

Whitesales have a range of sizes to provide 1.5m2 free vent area.  The Em-Vent S12 1300x1300mm, R7y 700x2200mm, R12b 800x2000mm, R16b 900x1800mm, R18 1000x1600mm, R22x 1100x1400mm all achieve 1.5m2 free vent area and are all stock items.  We also offer Es-Vent and Es-Louvre smoke vents in standard sizes to achieve these vent area values.

What angle do single leaf roof mounted smoke vents need to open?

Single leaf roof mounted smoke vent must open to a minimum of 140˚ in accordance with EN12101-2: 2003 Smoke & Heat Control Systems – Part 2, Specification for Natural Smoke & Heat Exhaust Ventilators.  Whitesales Em-Vent smoke vents open to 160˚ to provide maximum Aerodynamic Area (Aa).

I want to interface the Em-Vent Smoke Control panel to my fire alarm panel, is this possible?

The Whitesales Em-Vent Smoke Control Panel is able to interface with a fire alarm panel providing it is able to provide a ‘normally open’ signal going ‘close on alarm’.

I would like to incorporate the access hatch with a smoke vent, is this possible?

Whitesales Em-Vent and Es-Vent single leaf smoke vents are able to be manufactured with offset actuators to enable smoke vents to be utilised as access hatches.  This feature gives greater flexibility in design for buildings often enabling roof top apertures to be reduced in number by combination of smoke ventilation and access.  Operation of a smoke vent is via a separate system within the Em-Vent Smoke Vent Control Panel utilizing a key switch to prevent unauthorised access.

I have a project with a width restriction in a corridor, what is the narrowest certified vent that is available?

The narrowest certified smoke vent is the Em-Vent, which is available with an actuator at 700mm wide.  To meet a corridor vent requirement of free vent area of 1.5m2 an R7y 700x2200mm is available from stock.

What is the best size access hatch for a ladder?

Whitesales Ladderway access hatches are available from 600x600mm to 1400x1400mm, with the 900x900mm proving the most popular size.  Smaller that this size means clearance room is compromised for standard access for maintenance or inspection, although clearance for occasional access may be fine.  Larger sizes give opportunity for pieces of equipment or plant to be lifted through.

What is the best size access hatch for a companionway stairs ?

Whitesales offer two sizes of Es-Hatch stairway access hatch for a companionway stair.  The 750x1500mm is suitable for a steep stair of 80˚ and the 750x2500mm is suitable for a more shallow angle of down to 70˚ whilst still providing adequate headroom in normal circumstances.

What is the best size access hatch for a staircase ?

Whitesales offer the Es-Hatch stairway access hatch 750x3300mm for stairways access.  This accommodates between 42˚ and 50˚ stairway whilst providing adequate headroom in normal circumstances.