FAQ

Traditionally a conservation style rooflight would have at least one glazing bar dividing the glazing. It was this feature, along with the flush fitting profile that gave the product its distinctive appearance.

Today there are many conservation skylights available and a large number of these use stick on bars to try and give the appearance offered by the Victorian originals. Whilst opinions seem to vary across regions of the country, most Conservation Officers would like conservation rooflights to have a glazing bar to break up the glazing. Whether a stick on glazing bars offer that look or any longevity is up for debate so it is always worth discussing this with your Conservation or Planning Officer.

If your rooflight does require a glazing bar then we can produce ours with a traditional genuine bar which divides the glazing into a number of units. These bars give a traditional appearance much closer to the Victorian originals and are more likely to please your Conservation or Planning Officer. Whilst a genuine glazing bar provides a better appearance, it will affect the thermal performance of your rooflight, so it is always worth keeping the number of such bars to an absolute minimum.

For advice or to discuss your conservation rooflight requirements, please call our team on 01794 745445.

All Stella Rooflights are manufactured from laser cut, folded and welded 316 stainless steel sections, and given additional protection by a polyester powder paint finish to a C5 application.

This combination should ensure a long and low maintenance life but is subject to the following factors:
i) The location in which the product is installed
ii) The condition of the coatings when the rooflight is installed
iii) The frequency and quality of cleaning and maintenance

The protective coatings applied are able to offer a predictable longevity according to the location of installation. To ensure that our Stella rooflights offer the predicted longevity, they must be installed with the paint coating intact and be regularly maintained. Building products are frequently damaged on site prior to installation and should this happen any damage to the powder coating may adversely affect its longevity. It is advisable that Stella rooflights are handled and stored with care.

Keep the rooflights well protected until they are required. We recommend that all our roof windows are checked thoroughly for chips and scratches to the powder coating both at the point of delivery and prior to the installation. If there are shallow or superficial scratches or chips then these can be treated with a touch up paint available from us. If there are deep scratches or extensive parts of the powder coating are damaged then consult the building contractor or architect as the rooflight may need to be replaced.

Maintenance at regular intervals is essential to uphold the longevity of the rooflight powder coat and to ensure the guarantee is valid. This consists for the most part of cleaning the accessible parts of the product. Cleaning should be carried out regularly and at no more than 12 monthly intervals (subject to location). In areas exposed to extreme weather or along coastal areas, this time should be reduced to every 3-4 months. As the external surfaces of the rooflight are subject to the bulk of weathering and are largely inaccessible from the inside, cleaning should be carried out from outside if possible. If this is not possible the rooflight casement should be wound open to its furthest extent and then cleaned from the inside. Wash the accessible metal parts of the rooflight with warm soapy water, a soft cloth and rinse any cleaned sections with clean warm water. Do not use any abrasive cleaners or hard bristle brushes. The winding mechanisms should be maintained at least every six months although it can be done at more regular intervals if required. To clean the mechanisms use a damp cloth with warm soapy water. A non-oil based product such as a silicone spray or Easy Glide can be used but this may attract dust. Do not use a mineral or synthetic oil as this will eventually damage the mechanism.

Maintenance of the BioClean units must be followed in accordance with the Saint Gobain cleaning guide which can be viewed on our website. Failure to do this may invalidate the unit warranty. We recommend that you clear away any material that has lodged in the top gutter of the rooflight as if allowed to build up, an accumulation of leaves, twigs and other items can eventually lead to leakage at the rooflight head. In addition, chemicals contained in debris can have an effect on the powder coating at the top gutter. Open the rooflight casement to its fullest degree to ensure all debris can be removed. We also recommend oiling the hinges on all Stella rooflights to reduce wear at the point where the powder coating bears upon the stainless steel hinge bolts. A light engineering oil such as WD40 or 3in1 oil will suffice. Use oil sparingly and apply only to the middle part of the hinge. Should you have any queries concerning the treatment of scratches, damage or maintenance, contact our sales office on 01794 745445.

If you are comparing quotes and one is significantly cheaper than the other it is always worth digging deeper to find out why and if you are really comparing two equal products. Stella Rooflight offers the highest standard specification of any supplier and when combined with our UK design, manufacturing and assembly our quotes will often be at the higher end of the pricing spectrum. Whilst a higher upfront cost can sometimes put people off, it is always worth considering what the likely whole life cost of a product is likely to be. Will the cheaper product last as long, will it need more maintenance, does it offer the benefits of the more expensive skylight and most importantly, will it add value to my property. If you come to sell the property and have opted for a cheap steel framed rooflight or a skylight that is not in keeping with the original architecture, you may find yourself either needing to carry out expensive repairs to rusting frames or even losing potential buyers who are looking for original features.

A number of competitors are offering a significantly cheaper alternative to our conservation rooflight design but we would certainly encourage anyone comparing those products to our own, to ask questions that will allow a more direct comparison. To most people rooflights simply allow light and ventilation into their roof space; so what makes one product vary from another? and why is price so closely linked with quality? There are some very big and well-known brands in the rooflight market and these tend to be mass produced in a range of standard sizes, production line manufactured and cheap enough to entice major housebuilders to use them in the thousands.

But what if you need something unique for your project? What if you want an input into how your glazing solution will look and operate? Many roof window suppliers are not set up for the custom made one-offs or the bespoke skylight designs and options. Mass production works by producing goods in large quantities, often using standardised designs and assembly-line techniques to minimize costs. It does not usually allow for changes or alternations to make your custom made glazing ideas a reality. In addition to large scale production, factors such as location play an important part in the cost of producing a rooflight. Significantly lower labour and material costs allow manufacturers to produce and sell products for less. That said; the quality of the product can usually be directly linked to the amount the manufacturer spends on those two areas. There are many key factors in rooflight design including frame materials, glass, paint, mechanisms and the people used to produce the goods. It stands to reason then that if you try and save every penny to make your goods cheaper, then something has to give at the quality end.

Bespoke or custom built rooflights can be more expensive, even if they are not particularly large. This because each Stella Rooflight is tailor made and begins with a brand new set of drawings produced by our design team. When designing your bespoke tailor made Stella rooflight you will be able to choose many of the materials including, your glazing specification, your timber type and your powder coating colour. If you would like to discuss a bespoke, custom built rooflight for your project, call our team on 01794 745445 or use our contact form.

With so many options available from so many suppliers it is quite often difficult to compare like for like quotations. Below are a few pointers to consider when it comes to getting the right rooflight for your project:

Do I have a pitched or flat roof?
The design for a flat rooflight is different to that of pitched rooflight and flat version will require a kerb/upstand section built onto your roof. If you have a sloping roof you can generally find rooflights that can be installed between 17 and 70 degrees. It is always important to know the roof finish and mention the pitch of your roof when talking to rooflight suppliers to ensure you are quoted for the right product.

How big can my skylight be?
Modern glazing technology allows some very big areas of glass but if you are working with an older or Listed property then it is advisable to use conservation rooflights and keep to smaller sizes. More modern projects are better served by more contemporary skylight designs which have much larger areas of high specification glazing without the more traditional glazing bars used in conservation roof windows. Just remember that the bigger the glass area the thicker and heavier the glass will be, so you may need to crane your rooflight into position.

Do I want it to an opening or fixed design or can it be a combination of the two?
Some rooflight manufacturers specialise in fixed skylights and others in opening. Having fixed rooflights quite often works out more cost effective because you can have larger pieces of glass without the overhead of expensive electric mechanisms. Quite often we advise our customers to have a mix of both, particularly on bespoke rooflights. This allows Stella Rooflight customers to have the best of both worlds, utilising high specification fixed glazing with smaller opening vents operated by manual mechanisms, gas struts or electric actuators.

How would I like my rooflight to open?
This will depend on whether you need ventilation or access to the roof? If you have other sources of ventilation then it is probably advisable and more cost effective to have a fixed (non-opening) roof light. Smaller rooflights tend to operate manually but if you opt for a large rooflight most will be operated with electric actuation. There are a wide variety of actuators available and products like our bespoke Stella conservation rooflight operates with a small cill mounted actuator to push the casement open. Larger bespoke rooflight designs can have concealed actuators to lift casements.
What glass should I use in my roof light? There is no ‘one size fits all’ option and so glass specification should be chosen to reflect your most important requirement. Stella Rooflights provide an exceptional u-value with the added benefit of self-clean, solar control glass by using BioClean Natura with argon gas cavities and Planitherm. If you need your rooflights to provide better sound performance you could opt for a more specialist glass options. Speak to one of our team concerning your rooflight glazing options.

Will my location affect the performance of my rooflight? If your project is located near to the coast or in an area of high pollution it can make a difference to the life of your roof light. That is why all Stella rooflights are manufactured from a 316 stainless with a C5 powder coat finish, so you can be sure that your rooflight is protected longer than any other metal rooflight on the market. High salt content or pollution can attack the protective paint coatings which in the case of standard carbon steel rooflights will reduce the effective life considerably.

Almost every activity that we do within the home produces water vapour. Whether it is cooking, washing or simply breathing we all add moisture to the atmosphere around us. Under normal circumstances the air within your home is able to support or absorb this moisture and hold it in suspension.

Moisture rich air circulates around the house and is changed as it travels out of windows and doors. This happens most months without any problems and you never notice any visible signs. That is until the balance shifts and gap between internal and external temperatures increases. One particular activity that likely to increase water vapour in the air is drying laundry indoors. Yes your clothes will dry quicker in the house but where does that water from your clothes go? It does not simply dry up and disappear but is absorbed into the air within the home.

When the summer months draw to a close, we start to keep the windows and doors shut for longer as the evening temperatures drop off. Our activities of cooking, washing and breathing continue unchanged but in the colder conditions and with windows closed, there are fewer air changes in the home. The air continues to circulate picking up more and more moisture as we go about our normal lives.

The amount of moisture or water vapour that can be held is increased by putting on the heating but there is still a limit to how much water the air can hold. In todays’ world of high energy prices more and more of us are holding off that decision until absolutely necessary but the heating does much more than just warm us.

A good example of the air reaching saturation point is when we emerge from a bath or shower and see steam floating around in the bathroom. The air has absorbed as much as it can and you can suddenly see all this moisture before your eyes. We accept this as the norm and in most cases the water vapour will deposit itself on your mirror or tiled surfaces before clearing through into another room or out of the window.

Although not so exaggerated as in the bathroom scenario, our normal living activities produce large amounts of moisture which for certain months of the year start to manifest as condensation.

Condensation is the result of moisture saturated air coming into contact with a cold surface and then shedding its water onto that surface. Traditionally condensation would form on window frames and the glass as this would have been the point where the colder temperature of outside had the best opportunity to pass through into the warmer house.

Years on from the old metal frame windows, most modern homes now have energy efficient glass in thermally broken frames, problem solved? Unfortunately not; in fact modern construction methods actually make the incidence of condensation more likely as the airtight designs reduce the opportunity for air to flow and change within the homes. Years ago most homes had a chimney and ill-fitting windows and doors which allowed the air to flow. Condensation appeared on the windows and that was widely accepted.

Modern windows and skylights do not suffer as much from condensation but modern living and home design actually increases the moisture within the air. This is not a problem when the heating is cranked up but without it you are more likely to see mold growth in the backs of wardrobes, the hall and in bedrooms than you are condensation on your windows. Two sleeping adults produce around 1 ½ pints of moisture in 8 hours which is absorbed as water vapour into the atmosphere. If you turn off your heating at night as the temperature drops, the air cannot hold as much moisture and it will deposit that when it comes into contact with a colder surface.

A new 3 bedroom house will absorb around 1500 gallons of water during the construction, much of which is dissipated into the indoor atmosphere during the drying out period. Adding heating and carpet will help but that is still a large amount of moisture being added to the air which is likely to be seen as condensation somewhere in the property.

The architects and product manufacturers continue to try and design out condensation from our homes but our very way of life still remains the biggest problem. Cooking, showers & baths, drying clothes, better fitting windows and doors, no chimney all add to the problem and increase the risk of condensation.

Condensation is not caused by products but merely reflects the atmospheric conditions that we as occupants create. As such, we also have a responsibility to manage both the risk and the water when it does occur. Simply ignoring those beads of water on the glass in the morning will ultimately result in the discolouration of your window frames, silicone and rubbers. Ignore the water in your bathroom and the grout and silicone will go black and you may suffer from mold growth in corners and on the ceiling.

Unchecked, condensation will damage paintwork, curtains, wall coverings and fittings. Over time it will damage items beyond repair and could be costly. It is natural to regularly vacuum the carpets or dust the furniture, whereas maintaining our windows and rooflights seems less of a priority. Most view windows and skylights as unimportant or even products that do not require regular care, which is far from the truth. All products require some maintenance, particularly those in coastal or high pollution environments. Why then should it not be as natural to clear away the water from the bedroom windows in the morning or wipe down the tiles in the bathroom after use and check the walls for any spots of damp or mold each month.

Despite the introduction of modern glazing, genuine steel framed windows and conservation rooflights will always have a slightly increased risk of developing condensation particularly when used in modern buildings. The Glass & Glazing Federation produce an information booklet about causes and advice for condensation which can be viewed on our website (www.stellarooflight.co.uk). This guide not only explains how condensation forms but also gives practical tips about reducing the risk of it happening.

Condensation is caused by the way we live combined with a perception that modern products are somehow maintenance free. With a better understanding of how condensation comes about we can take action to reduce the possibility of it happening and care for our products when it does. Should your window or rooflight or ceiling suffer from condensation or mold growth it is most likely to be the reflection of the environment rather than any serious product failing. Clearing any moisture away from the affected area will extend the product life and stop unsightly mold patches spreading.

Stella conservation rooflights can be used from a minimum pitch of 17 degrees to a maximum of 70 degrees. If you are using a fixed design it is possible to drop as low as 15 degrees and as steep as 75 degrees.

It is not recommended that you installation our opening rooflights into a pitch which is lower than 17 degrees as our flush fitting design may cause issues with removing water from the outer frame area. Although it is unlikely that water will enter through the casement as Stella rooflights comply to BS EN 14351-1:2006 + A1:2010, there is a risk that water will pool at the foot of the rooflight where the frame and lead meet. The rooflight frame must not be submerged for long periods and it is vital that the pitch of the roof allows a suitable run off. We do not recommend installation below 17 degrees but should you choose to install our product below this pitch, please ensure that you consult your roofing contractor prior to installation.

Stella rooflights have fixing lugs that position onto the side of the rafter and therefore whilst the measurement of the internal face is important, the width and depth of the rafters are less so (although you should have a structural engineer assess whether they are strong enough to support a rooflight). If your internal rafter width varies, it will be necessary to provide the smallest width and pack out and gap.

In most situations, the internal area will have a plasterboard finish that covers the rafters. The most important measurement when requesting a quotation is the distance between the rafters. Unlike many skylight suppliers which only offer standard off the shelf sizes, Stella rooflights are manufactured as bespoke items to your requirements and there are no additional costs for having a size to suit your project specification.

The Stella range of conservation style rooflights require a traditional lead flashing installation which should be undertaken by a professional roofing contractor. Stella Rooflight offer a handmade lead flashing kit which includes the flashing for the head and cill along with pre-formed soakers for the sides. If you would like to use a Stella Rooflight flashing kit, please tell our team when requesting your quotation. At this point we will need to know whether your skylight will be situated within a clay tile or slate roof. If you have a slate roof we will require the slate sizes. For diminishing slates we can only produce soakers to the largest size which should then be trimmed on site. If you have a pantile roof application please speak to our team.

The best way to get the process underway is to speak to one of our team who will be able to discuss your design requirements and application for the rooflight before putting a written quotation together. All Stella Rooflights are made to order and as such there are a number of options that you can change to suit your own personal requirements. These include a number options including glazing specification, colour, change the wood that your liner is made from, add or remove glazing bars and have opening or fixed casements.

Should you decide to proceed with a quotation we will then write to confirm the order and instruct our design team to produce the approval rooflight drawings. This process can take up to 10 working days. When the drawing is prepared we will email it over to you so that you review the information and discuss with your builder or planning department. Your drawing will provide a visual of the rooflight along with full sizing and weight details. If changes are required, we will update the drawing until you are ready to sign it off for manufacturing.

The rooflight manufacturing process takes approximately 7 weeks.

There are many different ways to describe skylights and the components used in installing and operating them. Not only this but the term skylight is also referred to as many different things such as rooflight, roof window, sky light or occasionally people refer to them as Velux, who are of course are a manufacturer of skylights.

Actuators – are the mechanisms used to electronically open and close the skylights. At Stella Rooflight we use a range of electronic actuation subject to the requirements of the opening casement. If you require your roof window to have some or all of the casements opening then our team will explain what is achievable when you make your enquiry.

Baseplate – this is the part of the rooflight that contains the hinges for the casement to be bolted onto. The fixing lugs are located on the underside of baseplate along with the wooden interior liner. This piece of the skylight sits between the structural support timbers (rafters).

Bespoke Skylights- this term is used to describe a rooflight which is custom made to your specification. This can be a change to a conservation rooflight, a more contemporary roof window or a range of roof windows for a flat roof application. When making your enquiry for a Stella Rooflight you have the ability to change a whole range of options including glazing specification, colour, change the wood that your liner is made from, add or remove glazing bars and have opening or fixed casements.

Casement – this is the opening piece of the rooflight which contains the self-clean glass units. This section is fixed onto the baseplate hinges. The casement is viewable once fitted in the roof
Coastal Location – We produce the rooflights to a very high standard that are suitable for use in coastal locations as standard. If you have any questions about the location of your property or the likely implications of high salinity or pollution content in the atmosphere, please talk to our team.

Condensation – condensation is the water that results from the conversion of water vapour in the atmosphere. The air in our homes always contains water vapour which is usually invisible. The warmer the air, the more water vapour it can hold but there is a limit to the amount it can hold for a given temperature. Should you require additional information, please ask our team for a copy of the Glass & Glazing Federation fact sheet.

Conservation Rooflight – during the 18th century rooflights, in their most primitive form, were used to bring light into agricultural buildings. It therefore seems uncanny that todays rooflights are yet again providing an architectural design solution to the increasing trend of converting old or disused industrial buildings into domestic dwellings or business premises. Conservation rooflights are easily recognised by their low profile which means they sit flush and remain unobtrusive to the buildings original architecture. Another characteristic is their slender appearance as conservation requirements stipulate that a minimal amount of framework should be visible. This design feature becomes even more significant when rooflights are placed next to each other.

Contemporary Skylights – A stylish and streamlined roof window for customers who are seeking a more modern look for their roof glazing. The design remains low profile and unobtrusive whilst offering a high specification of energy efficient, self-clean glazing. These typically do not have glazing bars in the same way that conservation rooflights do.

Escape Rooflights – although some rooflights are hinged on the side, our escape version are top hung to reduce any possible issues with light rain and to retain a matching appearance when installed alongside our standard range. Stella access or escape skylights and are fitted with gas struts so the skylight casement stays open. Supplied with a brass winding mechanism for daily use, the gas springs should only be deployed when the casement is required to stay open. Further details can be obtained when speaking to our team.

Gas Struts- are pressurised cylinders that are attached to the rooflights so that they can remain open unaided in a similar way to the boot of your car.

Hand Winder- is the mechanism used to open and close the rooflights when the rooflights are within reach. These typically have a handle or a wheel on the end to aid operation.

Pole Winder-is the mechanism used to open and close the rooflights when the rooflights are out of reach. This type of rooflight mechanism would usually be operated by a separate crank pole.

Head Detail- is the top section of the rooflight

Jamb Detail-are the side sections of the rooflight

Cill – this is the bottom section of the Rooflight

Linking bars-are the bars used to link skylights together so that they are in continuous runs. Occasionally specifiers refer to these as Studio-Linked but we call them Stella Link Light.

Listed building – a building or other structure officially designated as being of a special architectural, historical or cultural significance. If your property is Listed you will need to work closely with your local authority before making changes to the building fabric. An excellent resource for Listed property owners

Overall Sizing- the maximum width and length of the baseplate, much of which is covered by the tiles or slates.

Pitched Roof- is a roof structure where the roof is set at a slant. Our Stella conservation skylights can be used between 17 and 70 degrees in slate and tile or 30 and 60 degrees in a pantile roof.

Roof Window- is an architectural term for the frameset with glass which is fitted to an opening in the roof to admit daylight.

Rooflight- is another way of describing the frameset with glass in that is fitted to an opening in the roof to admit daylight

Skylight-is another word to describe the frameset with glass in that’s fitted to an opening in the roof to admit daylight.

Self-Cleaning Glass- An important technological breakthrough was introduced to the UK in 2002, in the form of the worlds first self-cleaning glass. Considered by many to be an impossible dream, self-cleaning glass makes maintaining rooflights significantly easier. Saint Gobain BioClean is effectively the same as conventional glass, but with a specially developed coating on the outside, that once exposed to daylight, reacts in two ways. Firstly, it breaks down any organic dirt deposits through a photocatalytic process, and secondly, when it rains, instead of forming droplets, the water spreads evenly over the surface and takes the dirt off with it. It is kinder to the environment than ordinary glass and it is the ideal choice for situations where cleaning will be costly or difficult.

U-Value- often called the overall heat transfer coefficient and describes how well a building element conducts heat. Our standard triple glazed units have a U-Value of just 0.5 meaning that a Stella rooflight can achieve exceptional overall u-values from as low as 1.1.

As a Stella rooflight is fixed into the sides of the rafter, this is normally the most important size and sets the requirements for the other measurements. The clear viewable size is the glazed area that is viewable from the inside once installed and takes into account the fitted interior wooden liner that is positioned inside the base frame. The overall size is given to inform the installation team just how much space is required on the outside of the roof however, most of the outer section of rooflight will be covered by the tiles or slates.

We would always advise that you check with your local authority before installing Stella conservation rooflights. There are many factors that will decide whether you are granted permission to use rooflights and if your property is Listed, in a Conservation Area or an Area of Outstanding Natural Beauty, you may find restrictions concerning the type of rooflight that is allowed. Fortunately, a Stella conservation rooflights replicate a traditional Victorian rooflight design in that it provides a neat and flush fitting appearance, a black paint finish as standard and can be produced with genuine glazing bars; all whilst remaining unobtrusive to the original architecture of your building.