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Frequently Asked Questions

General information about VELUX Skylights

Where can I purchase VELUX products?
VELUX products can be purchased through most NZ dealers such as Bunnings, Carters, ITM, Mitre 10, Placemakers, etc.. You can also purchase our products from a VELUX Certified installer as a Supply & Install package. A list of local installers and dealers can be found here:

Go to the VELUX Skylights Dealer locator
Where can I find blinds for my VELUX Skylight?
You can see a full range of blinds in our Blinds section.

Go to VELUX Blinds
Can a VELUX Skylight leak?

VELUX skylights use flashing kits that are specific to roof pitch and roofing material. Provided the proper VELUX flashing is used and installed correctly, we will guarantee the product against leaks for the period specified in our warrantees.

The unique construction of VELUX windows and flashings ensures the safe drainage of rainwater from the roof above the window, providing complete weatherproofing and preventing leakage. Because the roofing material covers both the top and the sides, VELUX flashings are largely unobtrusive.

VELUX flashings are compatible with virtually any type of roofing material, from standard covers such as slate and tile to corrugated sheeting or even thatch.

VELUX undertakes extensive testing to ensure that all products perform to the very highest standards. Our windows and flashings are subjected to some of the world's most severe artificial rain and wind tests.

In the rare event of experiencing any issues with your VELUX product, please contact us immediately.

What amount of snow can the Skylights withstand?

Snow loading (NZ has 5 zones from up to 1.5 Kpa to 2.0 Kpa by altitude).

The Roof Window GGL/GGU with --73 glazing can withstand evenly distributed loads up to 2.75 Kpa (2.75 Kn/m2).
We strongly recommend to remove the snow from the Roof Window/Skylight at least once a day during heavy snow periods otherwise the top-casing and coverings can be deformed. For use in very heavy snow areas we also recommend to use insulating glass units with laminated glass towards the inside be-cause if the glass should break for other reasons, the interior laminated glass will be kept together by the PVB interlayer so that glass or objects coming from outside cannot fall through the window (GGL/GGU with –73 glazing or VSE/VCE with –04 glazing).

Are VELUX Skylights thermally broken?
Thermal breaks are only required in aluminium joinery to reduce the heat loss through the aluminium frame as aluminium is a good conductor (unlike timber).
 
VELUX skylights have a "composite" construction with external aluminium cappings and an internal timber frame (VSE, VS, GGL, FS) or a timber curb (VCE, VCM, FCM). This "composite" construction ensures that all VELUX skylights have a much higher thermal resistance than an aluminium framed window or skylight.
 

VELUX skylights therefore do not require a thermal break to achieve very high thermal resistance values (R-values).

See VELUX Skylights technical values

Are VELUX products BRANZ appraised?
BRANZ appraisals are sometimes used by new products to the New Zealand market to show that they meet the requirements of the NZ Building Code.
 
VELUX products meet the requirements of the NZ Building Code as shown in the VELUX Product Technical Statement which is available for download from our website.
 
VELUX skylights have been sold in NZ for 30 years and have an extensive and proven history of use in the NZ market.
 
A BRANZ appraisal provides no more security to customers than a Product Technical Statement as, in both cases, an extensive history of use in the NZ market is still the most effective assurance  that customers can get from a product supplier.
What is a Product Technical Statement?

A Product Technical Statement provides information on how products meet the requirements of the NZ Building Code (as do BRANZ appraisals).

See VELUX Skylights product technical statement

Do VELUX Skylights use “Warm Edge” technology?
All insulated glazing units (ICU's) used in VELUX Skylights (VSE, VS, FS, VCE, VCM, FCM, GGL & GGU) incorporate stainless steel spacers with "warm edge" technology to reduce condensation and to increase the energy efficiency of the complete skylight unit.
What is the Insulated Glazing Unit (IGU) construction?
All IGU’s use a stainless steel spacer with “warm-edge” technology”:
 
                                    Inside glass                  Cavity                         Exterior glass
VSE & VCE   --04          5.4mm laminated           9mm argon                   3mm toughened LowE3
VS & FS        --05          3mm toughened            11mm argon                  3mm toughened LowE3
GGL & GGU --73           5.5mm laminated           14.5mm argon               4mm toughened LowE2
VCM & FCM --05           3mm toughened            11mm argon                  3mm toughened LowE3

Electrical products

I already have a VELUX roof window GGL/GGU and would like to obtain all the benefits of an electric one, what should I buy?
Call VELUX on 0800 650 445
What VELUX Skylights come with a rain sensor?
VELUX ultimate "Plug & Play" Skylights VSE and VCE models comes with a rain sensor as standard to ensure automatic closure with the first drop of rain.

Alternatively you can add a rain sensor to our Pivoting Roof Windows GGL and GGU models.

Go to VSE Electric Opening Skylight
Go to VCE Low Pitch Opening Skylight - Electric
Go to GGL/GGU extras
What wiring do I need when pre-wiring for a VELUX control system?
The KLC500 control system is the central unit and all cabling must run to its central location. The KLC500 must not be located in a ceiling, roof or wall cavity. It should be located on a wall surface where adequate ventilation is available. The KLC500 requires an adjacent 3-pin plug socket.
 
The following are the standard cables supplied and suggested cables to use for pre-wiring:
 
KMG 100
Standard       2x 0.75mm2 core flex
Pre-wiring     < 20m   2x 0.75mm2
                   < 40m   2x 1.50mm2     
                   < 60m   2x 2.50mm2
 
All cables are colour coded to match the terminal connections. The GGL is “pre-drilled” at the top frame for KMG. In all cases the cable must be run before the flashing is installed.

Sun tunnel

Will the ceiling diffuser get dirty?
The diffuser is tightly secured with a gasket. If for some reason it is necessary to clean the diffuser pan, the diffuser can easily be loosened and the dirt removed.
Can end-users install the VELUX Sun tunnel themselves?
It is always advisable to have a professional install any VELUX product.
What is the big difference between this VELUX Sun tunnel and the competitors?
The VELUX Sun Tunnel has a low profile design and blends beautifully with the roofline. No domes or bubbles on your roofline result in an aesthetically pleasing look. You can also calculate the amount of daylight a Sun Tunnel will give you, based on exact room dimensions, orientation and location. 

Calculate your Daylight 

Our VELUX Sun tunnel has an integrated frame and flashing, which means that you do not have to buy a separate flashing - everything is included in one box.
Can the VELUX Sun tunnel be installed in flat roofs?
No, the VELUX Sun tunnel can be installed on roof picthes from 150 to 600 inclusive. For flat roofs we recommend the use of a Low Pitch Skylight.  
Can the VELUX Sun tunnel be installed in a raking/sloping ceiling?
The VELUX Sun Tunnel is designed mainly for installations where there is a larger distance between the ceiling and the roof. The gap between the ceiling and the roof needs to be atleast 400mm for installation of the VELUX Sun Tunnel.
How do I get as much light as possible from my VELUX Sun tunnel?
Facing north is always best (in the Southern Hemisphere). Keep the flexible tunnel as short and straight as possible. Of course the time of the day, season of the year, position of the sun and the longitude/latitude will also influence the light output. Even the colour of the walls in the room will affect the perception of light. The Rigid Sun Tunnel gives you 3 times more light than the Flexible as it has a highly reflective surface.

You can also calculate how much light each will give you depending on your exact situation - size of room, height of celing, position etc., by using our Daylight Calculator.

Go to Daylight calculator
What is the maximum length of a VELUX Sun tunnel?
The standard VELUX Sun tunnel with a rigid tunnel can be extended with ZTR extension pieces to a maximum of 6 metres.
How is the light output from the flat glass compared to the acrylic domes?
Testing shows that the difference is very small. The major advantage of the glass is that it will not fade and be scratched over time as the domes, which reduces the efficiency substantially.
Should the VELUX Sun tunnel be insulated?
In general, insulation is not necessary. However, in very cold climates it is recommended because of the big difference in temperature within the tunnel and in the loft.
Will the glass withstand heavy hailstorms?
The glass is 4 mm toughened glass which is very strong.
How large a room can a VELUX Sun tunnel light?
A room or hallway of 9-10 m² would be properly lit. You can use our Daylight calculator to find out about your specific situation, room size, ceiling height etc.

Go to Daylight calculator
What is the size of the VELUX Sun tunnel?
The VELUX Sun Tunnel diameter is 350mm. The dimension of the square sash visible on the roof is 470mm x 470mm. Please note that the roofing material will nearly cover up the flashing and only a little more than the sash will be visible.
In what kind of rooms do you recommend the installation of a VELUX Sun tunnel?

– bathrooms/toilets
– hallways
– utility rooms/laundry rooms/storage rooms
– other dark places  

What kinds of materials are used for the VELUX Sun tunnel?
Frame and flashing are made from PU (polyurethane). The flashing features a lead-free bottom section
Sash = ASA (UV-stabilised ABS plastic)
Glass unit = 4 mm toughened, insulating glass unit
Diffuser = ABS
Tunnel = highly reflective metallised polyester for the flexible version and aluminium with a layer of silver for the rigid version
What about technical values, r-value etc?
No official, international standards exist for evaluating the technical performance of "tubular daylighting devices", and they should not be compared with "traditional window values". However, because of the demand VELUX has calculated and measured various values which appear from the Technical Specifications section. Be aware not to make direct comparisons with competitors due to the lack of standards.

Go to Technical data
What about condensation?
Thorough testing has proved that condensation does not pose any problems. The system is closed.

How is the diffuser removed?
Snap off the ceiling trim ring and release it. Then loosen the snap rings to unlock the diffuser pan. No tools are needed.
Can the light of the diffuser be blocked?
Yes with the new Blackout Blind for Sun tunnels
Is leaking a problem?
The VELUX Sun tunnel is installed by the well-known VELUX installation technique which ensures a watertight connection to the roof. Excellent results in our wind tunnel test facilities prove water tightness up to 600 Pa (class 9A) in 15° and 60° roof pitches in compliance with EN 12208.
What about maintenance?
The frame/flashing part is made of maintenance-free polyurethane (PU). The glass pane will automatically be cleaned by rain due to the special stay-clean coating on the glass. Compared to acrylic domes, which will most likely fade and be scratched over the years, the toughened glass in the VELUX Sun tunnel will remain nice and clear.
How long does it take to install a VELUX Sun tunnel?
Usually it will take 2-5 hours depending on the roofing material and any obstacles in the loft.

VELUX products installation

Is installation of VELUX Skylights possible at any roof pitch?

It depends on the model.

VELUX skylights/roof windows (VSE, VS,GGL,GGU and FS) can be installed at 15° - 90° . For installation in roofs below 15° please call VELUX New Zealand on 0800 650 445. 

VELUX Low Pitch Skylights , FCM,VCM and VCE can be installed from 0° degrees to 60° only.

VELUX Sun Tunnels can be installed from 15° to 60° only.

Can I operate a VELUX Skylight electrically?
Yes. VELUX has the first complete " plug & play " electric opening skylight – VSE. The VSE electric opening skylight comes with a complete electrical system for easy and fast installation.

The Pivoting Roof Windows (GGL or GGU) can also be electrified by installing the necessary components (window opener, control unit,rain sensors,  infrared receiver).

Go to VELUX VSE Electric Opening Skylight
Go to GGL/GGU Electrified Pivoting Roof Windows 
Can I install a VELUX Blind myself?
Yes. VELUX blinds are designed to fit VELUX Skylights and can be installed in a matter of few minutes. Models VSE/VS/GGL/GGU/FS have the Pick & Click system which makes the installation even easier. Make sure you follow the installation instructions provided to assure perfect fit!


How close to the ridge can I fit a VELUX unit?
We suggest no closer than 400mm to allow the top flashing to be clear of the ridge cap and to allow adequate fixing for the roofing material above the skylight without puncturing the VELUX flashing. If the unit is closer than 400mm to the ridge the flashing could run under the ridge capping as long as it is not nailed or screwed through.
Can I install a VELUX Skylight myself?
No. VELUX Skylights are products which we recommend are installed by a professional installer. Working with roof construction is a job for a skilled carpenter, not a do-it-yourself job. If you cant find a Builder we can help you.

Find a VELUX Certified Installer near you
Is installation the same regardless of the roofing material?
No, you have to be aware of the different kinds of roof materials.
How do I measure my roof pitch?
The most accurate method is by using a pitch-gauge placed on the roof itself. This gives an accurate reading of the degree of roof slope (a pitch-gauge can be purchased at local building supply stores). The alternative is to measure the rise over the run.
What size skylight do I need for adequate natural ventilation?
Approved Document G4: Ventilation states that the natural ventilation requirement is 5% of floor area. To give the approximate room size for which the unit will be adequate as the only ventilation source multiply the ventilation areas in the table below by 20.

See the Technical data
What size skylight do I need for adequate natural light?
Approved Document G7: Natural Light states that the daylight area should equate to minimum 10% of the floor area. NOTE: 10% of floor area gives 30 lux for 75% of the standard year. Typical lux requirements by area/usage are shown below:

Hallways 30 lux
Relaxation/Conversation 30 lux
Toilet/Washroom 50 lux
Dining 50 lux
Dressing/Grooming 300 lux
Reading/Deskwork 300 lux
Handcrafts/Hobbies 300 – 1000 lux (standard, difficult, critical tasks)

You can see how much light each product gives you in the table below. The figures shown represent the minimum 10%.

Go to Technical data
What dimensions for the light shaft?
The length of shaft is determined by the position of the skylight in the roof - the longer the shaft the bigger the skylight should be to allow for sufficient light and ease of construction. The lightshaft should be splayed out from the bottom and top of the skylight. At the top of skylight the shaft is typically returned to the ceiling at a right angle to the roof pitch (depending on roof pitch and length of shaft) the sides of the shaft are typically vertical as splayed sides can interfere with the trusses.
How close together can VELUX units be fitted?
If using EDW flashing – no closer than 600mm to ensure that flashings do not touch
If using EKW combi-flashing or EDL flashing a gap of 100mm is required between external frames.
What is the minimum clear opening required for a VELUX unit?
The VELUX frame has a rebated jamb that accepts up to 12mm lining materials. The backside of the lining rebate is 15mm in from the external frame. Based on this dimension a FS M04 can have a minimum clear opening of 750x950mm.

Repair

What do I do about clouding/fogging between the panes of glass?
Clouding of an insulating glass unit occurs when there is a break in the inner seal of an insulated glass, and as a result condensation forms between the two panes. If you encounter a problem with the seal of your glass, copy the serial number off the roof window and contact VELUX - we will be happy to help you determine if your product warranty still covers and what action can be taken to correct the problem with the seal.

Marks from suction discs on the glazing! What do I do?
Marks from suction discs can only be seen when the pane is humid. The marks occur where the discs have been in contact with the pane during production and changed the surface tension in the glass. However, the marks can be removed by following these instructions: Apply SONAX to the window pane and polish the window quickly and thoroughly with a soft cloth for 10 minutes. Alternatively, use a polishing machine (3-4 minutes with max 2000 revolutions per minute). SONAX liquid can be purchased at most car dealers.
Can a VELUX Skylight leak?
VELUX Skylights/Roof Windows use flashing kits that are specific to roof pitch and roofing material. Provided the proper VELUX flashing is used and installed correctly, we will guarantee the product against leaks for the duration specified in our warranties.

The unique construction of VELUX Skylights and flashings ensures safe drainage of rainwater from the roof above the window, providing complete weatherproofing and preventing leakage. Because the roofing material covers both the top and the sides, VELUX flashings are largely unobtrusive.

VELUX flashings are compatible with virtually any type of roofing material, from standard covers such as slate and tile to corrugated sheeting or even thatch.

VELUX undertakes extensive testing to ensure all products perform to the very highest standards.
Windows and flashings are subjected to some of the world`s most stringent artificial rain and wind tests.

Maintain

What is the purpose of the plastic bushings in the side frame?
The upper plastic bushing in the frame of a pivot hung window is used for securing the window sash with the sash barrel bolt in an open position and thereby increasing the ventilation.
The lower plastic bushing is used for securing the window sash, when the sash is fully rotated and in the cleaning position.

How often do I have to change the air filter?
Depending on appearance and condition, the air filter should be cleaned or renewed every year. Rotate the sash fully and secure by engaging the sash barrel bolt into the bushing at the bottom left hand corner of the frame. Remove the air filter from the filter rail. The air filter can be washed in ordinary household detergent and hot water.
What do I do about clouding/fogging between the panes of glass?
Clouding of an insulating glass unit occurs when there is a break in the inner seal of an insulated glass, and as a result condensation forms between the two panes. If you encounter a problem with the seal of your glass, then read the serial number off the roof window and contact VELUX - we will be very happy to help you determine the status of your product warranty, and what action can be taken to correct the issue with the seal.

Can I apply a film to the glass to decrease heat and light?
VELUX does not recommend the addition of any standard commercial film to the glass of our Skylights/Roof Windows. The addition of film or tint bought in a store will void the warranty on the glass. However, the glass is manufactured with a very energy efficient low-e coating. In addition, we also offer several sunscreening options that can be added to our skylights/roof windows to regulate light and heat.
Go to Blinds
Can VELUX units be sandblasted?
All VELUX the above units can be sandblasted. On units with 0075 glazing the sandblasting must not be on the glass with the LowE2 coating (the outside glass).