Designing Buildings - User contributions [en]

Rooflights and rust

2021-02-16T15:49:09Z

StellaRooflight: Created page with "File:clip_image001.jpg Conservation rooflights – what lies beneath? Paul Trace from Stella Rooflight offers an insight into steel framed conservation rooflights and the i..."

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Conservation rooflights – what lies beneath?

Paul Trace from Stella Rooflight offers an insight into steel framed conservation rooflights and the issue of rust, while highlighting some of the important considerations in the specification process.

Often specified in both period and contemporary projects, a steel framed rooflight design normally offers a superior glass to frame ratio, when compared with modern bulky rooflights. This extra access to both natural light and ventilation is one of the reasons why steel frames remain a popular choice. In certain applications, such as Listed buildings, conservation areas or sensitive replacements, steel framed rooflights should be the only choice, as these offer the most faithful replica of an original Victorian design.

The saying goes that ‘beauty is only skin deep’, however, when choosing or specifying rooflights it is important that you look beyond appearance and take into consideration the longevity and maintenance requirements of the materials used.

While the appearance of a steel framed rooflight is second to none there is an inherent shortcoming in the use of steel, particularly when used in a roof, and that is the potential for it to rust. The most common steel used for rooflights is mild steel (sometimes referred to as carbon steel) and in their naked form these materials offer virtually no resistance against rusting and will begin to corrode from the moment it comes into contact with the atmosphere.

Aren’t all steel rooflights the same?

Mild steel (iron containing a small percentage of carbon, strong and tough but not readily tempered), also known as plain-carbon steel and low-carbon steel, is now the most common form of steel for conservation rooflights, because of its relatively low price and versatility.

Almost all rooflights are produced with some type of paint coating, which is designed to keep the main structure away from atmospheric conditions; in the case of mild/carbon steel rooflights this prevents them from rusting. It is worth noting that mild/carbon steel framed rooflights are totally dependent on the paint to stop the frames rusting and even the slightest damage during installation can signal the demise of your rooflight.

One of the ways to avoid the risk of rusting associated with steel framed rooflights is to specify a 316 marine grade stainless frame.

The most obvious difference between carbon steel and stainless steel is the ability to [https://www.metalsupermarkets.com/how-to-prevent-corrosion/ resist corrosion], with stainless steel (as the name implies) being the more corrosion resistant material. Both carbon steel and stainless steel contain iron, which oxidizes when exposed to the environment, creating rust. It is the presence of added chromium in stainless steel, which makes it more corrosion resistant than carbon steel.

Without wishing to overcomplicate the point, the chromium will attach itself to oxygen more readily than iron, but when the chromium attaches to the oxygen it creates a chromium oxide layer, which protects the rest of the material from degradation and corrosion. Carbon steel does not have enough chromium to form this chromium oxide layer, allowing oxygen to bond with the iron, which results in iron oxide, or rust. Therefore, if corrosion resistance is a key factor in your choice of specification, stainless steel has to be the way to go.

Protective coatings

Steel framed rooflights will usually have a powder coated finish as this offers a better final appearance than wet spray alternatives. Unlike mild/carbon steel, which relies on the coating for complete protection, a 316 marine grade stainless steel rooflight mainly has the coating for aesthetic purposes.

Powder coat is a type of coating that is applied as a free-flowing, dry [https://en.wikipedia.org/wiki/Powder_(substance) powder]. Unlike most conventional liquid paints, which are applied via an evaporating solvent, powder coating is typically applied electrostatically and then [https://en.wikipedia.org/wiki/Powder_coating#Curing cured] under heat. Powder coating is mainly used for coating of metals and is designed to create a finish that is tougher than conventional paint.

Done correctly powder coating provides a high-quality finish, which gives metalwork a more durable layer than liquid paints can offer, while still providing an attractive appearance. Applied to the right environment criteria, powder coated rooflights are more resistant to diminished coating quality as a result of impact, moisture, ultraviolet light, and other extreme weather conditions.

Powder coat applications should always be applied to a standard suitable for the location of the rooflight. The environment in which a rooflight is located is classified from C1 to C5 with the lower end of the scale (C1) for internal use in buildings with clean atmospheres, right up to marine coastal/industrial with aggressive atmosphere (C5). The most common application for steel framed rooflights is to a C3 standard, which covers urban and industrial atmospheres with moderate sulphur dioxide pollution. While this should give a good standard of protection for most places in the UK there are a number of factors, which could affect the lifespan but are often overlooked.

It is easy to identify a property which is within 5km of the coast and specify the required marine coating, however if a property is located close to a road which is heavily gritted during the winter months this could potentially be as aggressive and corrosive to the powder coating as a property which is sited within a coastal environment. Ultimately identifying the right classification is not always as straightforward as looking up a postcode and careful consideration should be given to any environmental factors which may impact on the lifespan of the protective coating. Choosing the right durability is a question of cost but if the system doesn’t last long enough, rectification could be expensive for the end user.

To remove any risk and to make this confusing process easier, all Stella rooflights are painted to a C5 classification as standard so regardless of where your project might be, you can be assured of the highest level of paint quality at all times.

Paint coats are not magic coats!

Industrial coatings are no different to the paint on your car – they need cleaning and maintaining. Accumulated dirt may affect the design life of the system, and any mechanical damage almost certainly will. Therefore regular inspections should take place and minor damage must be touched up.

What many specifiers and end-users do not appreciate is that maintenance is not only required to keep up the aesthetic appearance, it is essential to prolong the life of the rooflight. From the moment the product is installed, the end-user is entirely responsible for providing that maintenance and failure to do so is likely to render any warranty void. The care and maintenance of a rooflight situated in a C3 environment is likely to be on an annual basis but this can increase to every three months in a coastal C4 location.

One of the biggest causes of steel rooflights rusting is a failure to adhere to maintenance guidelines either due their inaccessible location or an unwillingness to undertake the work by the end-user. In fact it is often only when the rooflight is leaking that action is taken, and in most cases this is far too late to save the rooflight from a level of degradation that renders the product unsafe or no longer functional. It is normally at this point where the homeowner is told that the warranty is void and the problem is theirs to deal with.

With a mild/carbon steel rooflight it is essential that the specifier and end-user are fully aware of what is required to extend the product life. All rooflight companies will issue guarantee and maintenance paperwork with their products and most go to great lengths to publish the information on their websites but it is not uncommon for that information to be overlooked or lost and only returned to long after the time for maintenance has passed.

It is not just coastal rooflights that benefit from the longevity offered by stainless steel and if the rooflights are to be fitted in an inaccessible location, or your client is unlikely to head out with a ladder and a bucket of soapy water on a regular basis, then 316 marine grade stainless should be your first choice. There is no getting away from the initial price uplift of stainless in comparison to mild/carbon steel but without the overhead of repair or replacement, the whole life cost of stainless can be considerably less than the lower quality alternatives.

In summary

If you are intending to specify steel framed rooflights be it for either a traditional or contemporary project, then the advice would be to give greater consideration to the type of steel rather than just the appearance. You need to consider the location of the property, further than simply its proximity to the coast, and whether there are any factors that may adversely affect the coating life. Not only this but you should make your clients aware of their responsibilities to undertake the maintenance and check with your chosen supplier as to what level of care is likely to be required.

With some leading rooflight companies only offering a standard 12 month warranty on their products and always having the strict maintenance requirements to fall back on, you may want to simply consider designing out any potential issues by specifying 316 marine grade stainless from the outset. While all rooflights and all paint coatings will require some level of care, a stainless option will not suffer the same catastrophic material failure as a mild/carbon steel rooflight should your client not keep up with the maintenance.

If you have any questions or require further information concerning the use of steel rooflights in your own project, please contact one of the Stella Rooflight team on 01794 745445 or visit [http://www.stellarooflight.co.uk/ www.stellarooflight.co.uk]

-Ends-

About Stella Rooflight

Stella Rooflight designs and manufactures high quality stainless steel bespoke rooflights. From design and production through to customer service, Stella has a single vision of doing things better than the industry standard. 
 
Stella produces exceptional rooflights that combine a flush fitting profile, while utilising the very best of materials and has become the first choice for discerning clients looking to bring natural daylight into their living spaces through premium quality rooflights. 
 
[http://www.stellarooflight.co.uk/ www.stellarooflight.co.uk]

01794 745445

Rooflight guide

2021-02-16T15:48:35Z

StellaRooflight: Created page with "83px Paul Trace, Director of Stella Rooflight offers some practical advice when choosing a rooflight for your home. Rooflights, or..."

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Paul Trace, Director of Stella Rooflight offers some practical advice when choosing a rooflight for your home.

Rooflights, or skylights as they are often called, are an excellent way to illuminate your home as they let in light from the brightest part of the sky and are not generally affected by external obstructions, such as tress or other buildings.They provide an even distribution of light and can brighten the dark areas in a room that vertical windows could never reach.

Of course, in applications such as loft conversions they may be your only option to let in light. However, they are also a popular choice for other parts of the home where the ceiling has the potential to be opened up, and can make an excellent addition to kitchens, bedrooms, bathrooms and living spaces. 
 
When specifying rooflights there are other aspects to consider beyond its shape, size, and the materials that it is made from. However, with so many options available, choosing the most suitable rooflight for your home can be anything but straightforward and there are a few key things to consider when deciding which product is best for you.

Choosing the right frame

The first thing to consider is the type of materials that are available for the rooflight frame. There are many different types of rooflight on the market catering for the modern contemporary style through to a more traditional look and feel.

Steel is the obvious choice for period properties and barn conversions, but they are now also being more frequently used in sleek new contemporary houses. Timber is a long-time favourite on homes of any style, but getting onto the roof to maintain the timber can be an awkward task. PVCu is also an option and is often the cheapest, but it will not provide the slim frames that metal is capable of, nor the natural look of wood.

The important thing is to select a rooflight that matches the look and feel that you are trying to achieve with your home, as it should blend in with your roof and the materials used throughout the rest of the house.

Glazing options

Once you have chosen the most appropriate material for your rooflight, you then need to consider the glazing options. Glazing can also be a tricky subject when specifying a rooflight, not least because there are so many different types of glass and glazing system available.

Aside from thermal performance you need to decide if you need toughened glass, for additional safety and protection against falling objects. Toughened glass does not mean that it is suitable to walk on, so if you need to stand on a rooflight it will require specialist glazing.

Self cleaning glass is another option. This technological breakthrough was introduced to the UK in 2002 by Pilkington, and 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.

You also have the option for double or triple glazing. This is probably fairly obvious, but you should always opt for triple glazing if budget allows as this will have a significant impact on the thermal performance of the rooflight. Few rooflight companies will offer triple glazing as standard, so be aware of this when you are gathering and comparing quotes.

It is also possible to have solar control glazing, which incorporates invisible layers of special materials on the glass that has the dual effect of allowing sunlight in, while repelling solar heat. Allowing sunlight to pass through your rooflight while radiating and reflecting away a large degree of the sun’s heat means that your indoor space stays bright and much cooler than would be the case if normal glass were used. Solar control glass is not necessarily coloured or mirrored glass, although such finishes can be applied for aesthetic purposes if desired.

Conservation style rooflights

If you have a Listed property or live within a Conservation Area, you may be restricted in the type of rooflight you are allowed to install and the chances are that you will need a traditional or conservation style rooflight that complies with strict building regulations.

The legislation around conservation rooflights state that new openings should generally be kept to a minimum and should be of a simple form that respects the building's character.

Dormer windows are not usually appropriate, so any new window openings in the roof will likely need to be rooflights, and in most instances metal conservation-style rooflights which sit flush with the line of the roof.

There are specialist rooflights that are manufactured for the heritage property market and conservation rooflights are easily recognised by their low profile which means they sit flush and remain unobtrusive to the building's original architecture. Another characteristic is their slender appearance as conservation requirements stipulate that a minimal amount of framework should be visible, particularly if rooflights are placed next to each other.

Another feature of a genuine conservation rooflight is the glazing mullion (glazing bar) which separates the glazing into sections. This follows the traditional conservation rooflight design and not only provides a more authentic look but offers increased strength for the opening section.

There are a number of manufacturers who claim to offer conservation roof windows but have opted to remove the traditional bar in favour of sticking something to the double glazed unit. Not only does this risk damaging self-clean glazing or worse, having it fall off after a few years, it also significantly detracts from the original conservation rooflight appearance.

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 to find out more on this topic is the Listed Property Owners Club, [http://www.lpoc.co.uk/ www.lpoc.co.uk].

Maintaining your rooflight

Maintenance of your rooflight is often something that manufacturers will be uncomfortable discussing with you, as they are all too aware of the difficulty in achieving this. However, the fact is that, like most any other part of your home, it will require a degree of care to maximise its lifespan.

Proper maintenance is particularly important if you are specifying a metal product; in which case it is highly recommended that you opt for a 316 stainless steel frame. Not only is this a significantly stronger material that can withstand greater stress and tolerance levels, but more importantly it is much less susceptible to rust.

It is widely accepted that mild/carbon steel will start to rust the moment that it comes into contact with the atmosphere. While steel rooflight manufacturers will protect steel with a paint application, the quality and level of maintenance provided by the homeowner will still determine the lifespan of the product. Now in the UK, where it rains (a lot!), a mild steel rooflight which is in direct contact with rainwater on a regular basis is eventually going to rust without regular maintenance. Furthermore, if you are fortunate enough to live within 5km of the coast, then the risk of the corrosion will be both fast and significant, due to the elevated salt content in the atmosphere.

It is advisable to check the manufacturer’s warranty when it comes to your responsibilities concerning maintenance, as you could be expected to clean and maintain your rooflight as often as 4 times a year in order to keep your guarantee valid! Which is obviously not ideal for anyone who has neither the ability nor inclination to climb up their roof every few months!

Rooflights and environmental performance

Consideration must be given to thermal performance and improving carbon and energy reduction in buildings. Part L of the building regulations is one of the tools used by the government to achieve these objectives. These regulations are subject to continual change and are set to change again in 2020, as the UK Government continues its drive towards greater thermal efficiency in house building.

Rooflights can have a major impact on the overall energy consumption of a building, cutting energy costs by reducing need for use of the electric lights. However, there are some products that perform well above the minimum recommended environmental standards that could bring about even greater benefits in terms of thermal performance. So deciding on the right materials, of which the choice is plentiful, will be key.

Whatever your choice of material it is important that you check the energy rating performance and U Values of the glazing. It is worth asking exactly how each product performed under test conditions as there are many variables within the test that will differentiate between an average performing rooflight and an excellent one.

Make sure you are comparing like-for-like

As with most things in life, you tend to get what you pay for, and this is particularly true when comparing the rooflight market. Prices often reflect the quality of manufacturing and materials used to produce roof windows. While prices may vary considerably, there is good reason for this and the difference in quality between the bottom and high end of th rooflight market can be night and day.

The rooflight may be one of the last things that you budget for, but it is also one of the most important finishing touches to your home. Opting for the cheapest product may come back to haunt you in the long run.

If you would like to speak to an expert about the right rooflight for your home contact Paul on 01794 745445,[mailto:paul@stellarooflight.co.uk paul@stellarooflight.co.uk] or visit [http://www.stellarooflight.co.uk/ www.stellarooflight.co.uk]

About Stella Rooflight

Stella Rooflight designs and manufactures high quality stainless steel bespoke rooflights. From design and production through to customer service, Stella has a single vision of doing things better than the industry standard, while providing the very best to its clients. 
 
Stella produces exceptional rooflights that combine a flush fitting profile, while utilising the very best of materials and has become the first choice for discerning clients looking to bring natural daylight into their living spaces through premium quality rooflights. 
 
[http://www.stellarooflight.co.uk/ www.stellarooflight.co.uk]

01794 745445

Large rooflights

2021-02-16T15:47:43Z

StellaRooflight: Created page with "THE ELEPHANT IN THE ROOF Paul Trace from Stella Rooflight discusses the practicalities involved in specifying large rooflights As a bespoke rooflight manufacturer we often see ..."

THE ELEPHANT IN THE ROOF

Paul Trace from Stella Rooflight discusses the practicalities involved in specifying large rooflights

As a bespoke rooflight manufacturer we often see grand plans with expansive areas of roof glazing, as architects continue to seek innovative ways in which to exploit natural daylight. As much as bespoke rooflights can certainly help bring these designs to life, there are some important factors that need to be considered when the glazing is turned from drawing to reality.

In recent years we have noticed a trend towards larger rooflights, with sizes regularly exceeding 2500mm in width, height or both. While Stella can certainly accommodate these, one has to appreciate the practicalities of weight, transportation and cost.

It stands to reason that the larger the rooflight, the thicker the glass will need to be, therefore as rooflight sizes get bigger their weight can increase exponentially. In context, our double glazed units comprising of 4mm thick glass weigh 20kgs per square metre and those using 6mm are 30kgs per square metre. Triple glazed units are 30kgs and 45kgs respectively. Add the stainless steel frames and hardwood liners into the equation and you can start to see how even a modest sized rooflight can weigh something akin to a small elephant! Indeed it’s not uncommon for us to produce rooflights weighing in excess of 200kg.

The reality is that when you scale things up even the simplest plans can start to become complex - a truth that should be all too familiar to architects. But before drawing that large rectangle on a roof plan, it is important to consider how the rooflight is going to be lifted from the ground to roof level and what the weight implications might be for the structure. Stella can weld stainless eyelets to the rooflight frame to aid the lifting process and we would suggest doing this on frames which weigh in excess of 100kg, which is the point where we expect a crane might be required. However, does the site have suitable access for any specialist lifting equipment, and has this additional cost been budgeted for?

The weight of an opening rooflight will also determine whether it is manually operated or requires electric actuation. We would suggest that our largest manually operated rooflight be around 1000mm wide or 1400mm high. Anything over this size will generally require electric actuation to lift the weight and in the case of wider casements, to provide a tight seal. Manual operating casements are less expensive than electric so there is a cost element that also needs to be considered when specifying larger opening rooflights. There is no maximum size in terms of what is possible to manufacture, although it is worth keeping in mind that a single piece of glass with an area over 5m2 becomes significantly more expensive.

Fortunately there are alternatives to using large expensive single panes of glazing, such as introducing glazing bars to reduce the unit sizes, linking frames, and having more than one casement. This not only makes the rooflights easier to transport, lift and install, but can also reduce the price.

If a large, single rooflight is the only option for your project then you must also make sure that it is safe to install. While rooflight manufacturers will be able to provide advice on a suitable specification for the job in terms of materials, glazing thickness, functionality and installation, it is ultimately the responsibility of a structural engineer to ensure that the product being specified is fit (and safe) for the building that it is fitted into.

To avoid any ambiguity it is fairly essential that the architect, structural engineer and rooflight manufacturer discuss large rooflight installations, likely weights, load bearings, site access, and lifting capacity at an early stage to avoid any problems down the line. It is not advisable to leave this for the builder to deal with at the last minute.

Another area for consideration should be the safety of large areas of glazing situated high up in a roof structure. Again, much like an elephant, there is a lot of grey area here!

Regardless of size your rooflight should meet the BS 5516-2: 2004 patent glazing and sloping glazing for buildings standard. This code of practice for sloping glazing defines that inner panes must always be laminated wherever rooflights are more than 5 metres above floor level (increased to 13 metres for panes less than 3 square metres) or are located over water (e.g. swimming pools). The Standard permits the use of toughened inner panes in other applications (for example where rooflights are less than 5 metres from floor level), but only where a stringent risk assessment for the particular application has been completed and has concluded that the use of toughened glass does not give any additional risk to those below the rooflight.

No glass is impervious to breakage so it is important to remember that roof glazing can and often does sit high above common areas in a home or office, so there will always be an element of concern if a unit were to break.

Certain industry bodies are calling for all rooflight glazing to include a laminated inner pane to provide greater security in the event that the glass breaks. Much the same as how car windscreens are required by law to be laminated to protect passengers from shattered glass in the event of an accident. There can be no dispute that laminated glass is safer because it forms a net when broken, which remains in one piece, whereas toughened glass breaks into little cubes and will fall down onto whatever is below.

As laminated glass is more expensive, the industry perhaps sees this as a way of combatting the cohort of cheap flat rooflight products that have flooded the market with potentially dangerous products.

However, laminating rooflight glass creates its own unique set of problems, as annealed laminate is prone to thermal fracture and heat stress. This risk can be reduced by polishing edges, however the low-e coating is not practical for polished edges as there is a risk of damaging the coating. Swapping the low-e coating for a laminated glass with treated edges is likely to have a negative impact on the thermal performance of the unit. Using products such as SGG Cool-Lite on the outer pane can help as this has both solar reflective and thermal coatings but these do not have a self-clean coating which is an important consideration for pitched rooflights as they are usually positioned out of reach.

Thermal Stress is created when one area of a glass pane gets hotter than an adjacent area. If the stress is too great, then the glass will crack. The stress level at which the glass will break is governed by several factors. Toughened glass is very resilient and not prone to failing due to thermal stress. Laminated glass and annealed glass behave in a similar way and the thicker the glass the less tolerant it becomes, which is an important factor for larger rooflights.

The temperature difference for a location can be calculated and the risk of breakage due to thermal reasons reduced. However, to assess the thermal risk you will need to take the following factors into consideration:

* Type of glass being specified for the insulating glass units
* Where the building is located
* Orientation of the rooflight
* Size of any glazing bars (if required)
* Details of any internal shading such as blinds or louvres
* The framing material and powder coat colour
* The window size and if it opens as this will change the angle to the sun
* Whether any radiators are located directly below the rooflight
* Any other details like other buildings or trees casting a shadow onto the glass.

The risk of thermal cracking and heat stress changes throughout the year with the highest risk seasons being spring and autumn due to the low angle of the sun and the lower evening temperatures.

Solar control glass either reflects energy or absorbs it to reradiate the heat outwards. By its nature it gets hotter than clear glass and glass that is designed for thermal efficiency alone. Whilst the majority of installations are within the operating tolerance, in some cases fluctuation in heat can put the stress beyond the limits.

Laminated glass is also heavier which needs to be remembered when planning lifting schedules and structural requirements.

Another issue experienced with laminated glass is a phenomenon called lensing, where images become distorted. This doesn’t necessarily cause such an issue with flat rooflight glazing where the view is a simple sky backdrop, but on pitched rooflights with a view of a landscape, this distortion will be a problem.

In summary, while there is a growing trend for projects to include more and larger rooflights, it is not as straightforward as just adding them to the plans. Clearly there is so much more to specifying large rooflights than meets the eye and while your rooflight manufacturer will be able to provide recommendations, ultimately having a better understanding of what glazing is required and involving a qualified structural engineer in the early phases will resolve any issues you may have further down the line.

For further information or to discuss your bespoke rooflight requirement contact the Stella Rooflight team on 01794 745445 or email [mailto:info@stellarooflight.co.uk info@stellarooflight.co.uk]

[http://www.stellarooflight.co.uk/ www.stellarooflight.co.uk]

Conservation rooflights

2021-02-16T15:46:29Z

StellaRooflight: Created page with "A GUIDE TO CONSERVATION ROOFLIGHTS There’s a huge variety of choice in the conservation rooflight market and selecting the right product can be confusing. Paul Trace from Stel..."

A GUIDE TO CONSERVATION ROOFLIGHTS

There’s a huge variety of choice in the conservation rooflight market and selecting the right product can be confusing. Paul Trace from Stella Rooflight offers some advice on things to consider when planning your project.

What is a conservation rooflight?

If you know that you need conservation rooflights for your project, the chances are that you have searched online and found plenty of choice. But what is a conservation rooflight and are they all the same?

To better understand what makes a rooflight a conservation style, it is important to understand the history behind this type of glazing and why the design is so sought after, not just on period properties but also more modern projects.

Without the ingenious concept of a rooflight the vision of transforming unconventional space into a well-lit property would be a daunting task, and in some cases an impossible option. For that reason, the conservation rooflight could be considered a highly influential building feature, which has given the construction industry a solution to introducing natural light into a property.

Although rooflights, or skylights as they are sometimes known as, have been around for centuries they became more prominent during the Victorian era as technology and building aspirations were stretched and roof glazing boomed. One of the most famous Victorian building projects was the Crystal Palace, which in 1851 used glazing on an unprecedented scale to showcase just what could be achieved.

Mass-produced Victorian rooflights for residential use tended to be made from cast iron and the earliest examples would have smaller, lighter panes of glass. This was partially down to limits of glass technology at the time but also because of excise duties, which were imposed on glass by weight in the mid-18th century. These slim, single glazed rooflights with multiple panels of glass were unobtrusive in design and sat flush in the roof. Today it is this minimalist appearance that many people are seeking to achieve in their glazing designs.

As a result of their popularity, there are lots of conservation roof windows on the market, which can make choosing the right one virtually impossible unless one can identify what the differentiations are. An effective way to make this distinction is to look closer at the attributes of a true replica of a Victorian conservation rooflight.

What material is the conservation rooflight manufactured from?

If a conservation rooflight is all frame, then there is little point in having one. Genuine conservation designs should be manufactured with slim clean lines and a low-profile to match the roofline. A number of skylight companies try to produce conservation rooflights using modern bulky aluminium profiles, which sit proud of the roofline, particularly slate. It is widely accepted that most authentic conservation rooflights are manufactured from steel because it provides great strength while offering a slim profile and excellent glass to frame ratios. There are many types of steel conservation rooflights and for unrivalled protection and lifespan, all Stella rooflights are manufactured from marine grade 316 stainless steel.

Internally Stella rooflights are finished with real wood linings. American ash is the most popular choice, but we can produce these from any timber required. The use of real wood gives a neat, warm appearance to the internal element of your conservation rooflight. Nowadays most rooflight suppliers tend to use cheaper soft wood or plastic, which is painted white as an internal finish and these liners can result in deeper frame profiles or reduced viewable areas. While a white internal frame can be sold as ‘clean’ or ‘neat’, these can sometimes feel a little soulless and is a finish more often associated with modern flat rooflights than traditional conservation products.

Single or double glazed?

Victorian rooflights would have been single glazed, however, today’s modern building standards are much higher and so single glazing does not meet the minimum requirements for thermal efficiency (Part L). Double glazing is now the most popular option for genuine conservation rooflights because glazing technology is such that a modern double glazed unit can provide a number of benefits while remaining reasonably slender. The units used in a Stella conservation rooflight offer both self-clean and solar control elements, while also providing excellent thermal efficiency with an inner pane of Planitherm One. Using warm edge spacer technology and argon gas our units are also silicone edge sealed, which gives them greater protection against UV light.

Some conservation rooflight suppliers are keen to boast about offering triple glazing in their products but while this does offer a slightly improved thermal performance it comes at the expense of appearance. The optimal spacer bar thickness is 16mm so any decent triple glazed unit is going to be almost 50% thicker than a double glazed version. Now with a flush fitting profile being one of the main requirements of a conservation rooflight, the introduction of triple glazing makes that almost impossible on some roof types.

Glazing bars?

It is often a stipulation from the Conservation Officer that a conservation rooflight should have a glazing bar to replicate that original Victorian appearance. It is not always the case but it is definitely worth checking whether you need them before purchasing any conservation rooflight.

If your conservation rooflight does require a glazing bar then it should be a genuine one. This is an area that separates those producing close replicas to the original Victorian rooflights and those who are trying to pass off modern skylights as something more traditional. A genuine glazing bar should be something which not only divides the glazing but also provides additional strength to the casement. So many conservation rooflights have something simply stuck or glued onto the outside of the glass which neither looks good nor provides any benefit to the rooflight. In addition, these stuck on bars (usually plastic) often attract dirt and mould and the lifespan of anything which is simply held on by tape or glue is unlikely to compare with a genuine steel glazing bar. A stuck on glazing bar is one step up from a felt pen but certainly should not be seen as a way to make a modern bulky framed profile meet the criteria of a conservation rooflight.

Top hung or centre pivot?

Once again, if you are looking for a close replica of a Victorian rooflight then a top hung profile will be the one you should opt for. Not only does a top hung design offer a more authentic appearance, it maximises the space below because the casement doesn’t stick into the room. Smaller top hung rooflights also utilise beautiful brass ironmongery to operate the casement whereas centre pivot designs tend to rely on modern plastic handles, which are out of reach and offer nothing to enhance the internal aesthetics.

Is any old conservation rooflight suitable for my project?

Just because something is sold as a conservation rooflight, that doesn’t automatically make it suitable for all building types. If your building is Listed or in a conservation area then the criteria for using conservation rooflights are much stricter and you should always gain approval, not only for their use but also the manufacturer that you would want to use.

There are only a handful of companies that specifically make conservation rooflights and even fewer who design, manufacture and assemble in the UK. Many conservation rooflights available online are simply other products which have been spruced up to look like they meet the requirements of that type of product. If you ask a supplier what the main difference is between their conservation rooflight and those used on modern buildings and the answer is a stuck on glazing bar, then you should avoid at all costs. Likewise, there are many elements which go into a genuine conservation design and price is always a reflection on quality.

Is there anything else I should consider when choosing my conservation rooflight?

With the UK Government pursuing a carbon neutral environment it is imperative that every action is taken to reduce energy consumption. Rooflights are energy efficient as they let in large amounts of natural light thus reducing the need for artificial lighting. Bringing natural daylight into your home is about much more than creating a bright, welcoming environment, it’s about protecting your health and wellbeing and achieving a more positive way of life.

One way to ensure that you maximise the amount of available light is to increase the size of your rooflights… or is it? Just because you have a large rooflight this does not always guarantee lots of light and you should always check what the finished viewable (often referred to as clear viewable) area of the rooflight will be. You might think that a conservation rooflight with a whole frame size of 900mm (w) x 1200mm (h) would have a similar clear viewable area regardless of the manufacturer, but you would be wrong and bulky framed modern types or the flat rooflights posing as pitched conservation styles will let in considerably less light than a genuine steel framed version.

With so many choices available, choosing the right conservation rooflight can be a bit of a minefield but with the right guidance and advice it need not be a stressful experience. At Stella we focus on each element of our conservation rooflight and our attention to detail is second to none, providing a realistic yardstick to measure the performance of other conservation rooflight designs. Our aim has always been to provide the best looking and best performing conservation rooflight on the market.

Whether you are building from the ground up, renovating an existing environment or extending to create more room, we know that quality is important to you and getting it wrong is just not an option.

We go further than anyone else to ensure only the finest quality materials are used in the manufacture of all our rooflights. We are the only rooflight manufacturer to use marine grade 316 stainless steel, offer a marine grade paint coating (C5 application) and provide a real wood internal finish on all our rooflights as standard. No other company provides such a high specification for conservation rooflights.

For further information or to discuss your conservation rooflight requirement contact the Stella Rooflight team on 01794 745445 or email [mailto:info@stellarooflight.co.uk info@stellarooflight.co.uk]

[http://www.stellarooflight.co.uk/ www.stellarooflight.co.uk]

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2021-02-16T15:44:04Z

StellaRooflight: Stella conservation rooflight at Shore Road Pumping Station on the Wirral

Stella conservation rooflight at Shore Road Pumping Station on the Wirral