Frequently Asked Questions
What is your current lead time/when will I receive my order?
Our current lead time for free delivery is approximately 2-3 weeks. However, if you wish to expedite your order, alternative delivery options can be selected via our website.
Do I need to be in to accept delivery?
No, our drivers do not require a signature upon delivery. If no one is available at the property, your order can be left in a safe place.
Will I be notified of delivery?
Yes, delivery is confirmed via email, along with an ETA once the van is loaded and ready for dispatch.
What is Softcoat?
Softcoat is a clear Low Emissivity Glass with a coating on the inside of the inner pane that reflects heat back into the building, giving thermal insulation performance.
Can we supply low profile spacers?
Yes, low profile spacers are available in 5.5mm, 7mm, and 8.5mm.
Do we supply triple glazed units?
Yes, please feel free to visit our website and select the Triple Glazed option for more details.
Can we offer a discount?
Our website will automatically calculate any discounted promotions we may be running. However, we aim to keep our prices competitive, and you are welcome to contact us to request any discount.
Do we supply Georgian bars?
Yes, Georgian bars can be located on our EXTRAs panel when ordering double/triple glazed units.
Do we supply obscure glass?
Yes, this is available in the OUTER glass section on our website. Once the pattern option is selected, you will be able to choose from the various patterns we can supply.
How much is delivery?
Delivery ranges from our free service of up to 21 working days. Alternative options are as follows:
- 3-5 working days - £150
- 5-10 working days - £50
- 10-15 working days - £20
Do I need toughened glass?
If any units are being used in a door, beside or above a door, in a roof, or sit below 800mm from the floor up, they will need to be toughened or laminated safety glass.
Can we supply Pilkington K glass?
We source our products from Saint-Gobain, and our equivalent glass is the Planitherm Total (softcoat), which can be found on the inner glass section of our website.
Difference between aluminium and warm edge spacer bars?
Aluminium spacer bars are commonly used in double-glazed windows to separate the panes of glass, providing structural integrity and thermal insulation. However, they are highly conductive, which can lead to heat loss and condensation issues around the window edges. Warm edge spacer bars, on the other hand, are made from materials with lower thermal conductivity, such as composite materials or stainless steel. These bars help reduce heat transfer, improving the window’s overall energy efficiency and reducing the risk of condensation. As a result, warm edge spacer bars are generally considered a better option for enhancing insulation and comfort.
What is the sightline?
The sightline refers to the height of the spacer bar, which is typically covered by the retaining bead and frame once the unit is installed. It’s the part of the spacer bar that remains visible before installation, and its size can vary depending on the type of unit and frame being used.
Is there a standard unit size?
There is no strict "standard" unit size for glass in terms of its dimensions. All our units are bespoke and made to order, therefore, we advise accurate measuring before placing an order.
Which glass should I choose?
Standard glass thickness is 4mm; however, the choice of glass depends on your specific needs, such as energy efficiency, sound insulation, privacy, or aesthetics.
What is the weight of the unit?
Our website will calculate the unit weight once your item has been added to your basket.
Can we supply single glazed?
Yes, you can place an order for single-glazed units through our website if needed. Simply select the appropriate options when placing your order or contact us if you have specific requirements.
Best spec for noise pollution/reduction?
For noise pollution, we would recommend selecting the 6.8 Laminated glass on the OUTER pane and 4mm on the INNER pane for double glazed units. The 4mm Inner pane will give you increased noise reduction. The different thicknesses reduce noise across the frequency range, so using a thinner inner pane helps cover the higher frequencies.
Can we supply solar controlled glass?
Yes, please feel free to refer to our data sheets to find the details of the SKN176 – Cool Lite. This option can be located on the OUTER glass section on our website.
How do I measure my units?
The most accurate way to measure your units is to remove the existing sealed unit and measure from glass edge to glass edge. Measure the width, height, and depth to ensure a proper fit.
Visible Glass Area: If you’re measuring the visible glass area only, you’ll need to ADD 25mm to both the height and width (12.5mm all around the unit).
Rebate (Tight Sizes): If you're measuring the rebate (the space where the unit fits into the frame):
For uPVC frames, deduct 10mm from both the width and height.
For wooden frames, deduct 6mm from both the width and height.
Do we offer installation?
Currently, we do not offer installation services.
Are the units argon filled?
Yes, all our units are argon-filled as standard. The argon gas between the glass panes helps improve insulation and energy efficiency by reducing heat transfer.
Maximum size for 4mm glass?
Units over 2.8m one way or over 2.5m² require a minimum of 6mm glass.
Can we supply units with holes?
Yes, we can supply units with circular holes to meet your specific requirements.
What is a spacer bar?
A spacer bar is a component used in double-glazed units to separate the two panes of glass. It maintains a consistent gap between the panes and helps create an insulating air space, improving thermal performance. Spacer bars are usually made from materials like metal or plastic and are filled with desiccant to absorb moisture and prevent condensation within the unit. The spacer bar plays a crucial role in enhancing the energy efficiency and durability of the glazing.
Minimum size for toughened glass?
The minimum size for toughened glass must be at least 250mm on one side. This ensures that the glass meets safety and structural standards.
How much tolerance should I allow?
If you are measuring rebate - rebate (tight sizes) you would need to deduct 10mm from the width and the height if the frames are uPVC. If the frames are wooden, you would need to deduct 6mm from the width and the height.
Can I have the obscure glass on the inner pane?
Yes, you are welcome to turn the unit for installation. Many installers still fit obscure glass the wrong way around deliberately. It provides a better watertight seal, flat surface against the rubber gaskets rather than rough. Also, the reflections from the windows look equal when the house is viewed from outside.
Should I remove the tape?
The tape is applied for protection during transit and installation. Please select the ‘no tape’ option on our website if you do not require this. If you wish to remove the tape after delivery, this can be removed by a sharp blade; however, please be careful as the edges will be sharp!
Can I collect?
Yes, you can collect your order. Please contact our support team to arrange a convenient time for pickup.
Which way round should I install the unit?
Standard units will always have the sticker placed on the outside of the glass. If the units have active or self-cleaning properties, they will then put the sticker on the inside pane.
How can I measure the overall thickness?
To measure the overall thickness of a double-glazed unit, follow these steps:
Measure the Glass Only: If the unit is still in place, measure the thickness of a single pane of glass using a digital caliper or a glass thickness gauge.
Measure the Spacer Bar: The spacer bar (the metal or plastic strip between the two panes) usually has its thickness printed on it. If not, you can estimate its thickness by measuring it with a ruler.
Add the Measurements: The total thickness of the unit is the sum of both glass panes and the spacer bar. For example, a unit with two 4mm glass panes and a 16mm spacer bar would have an overall thickness of 24mm (4+16+4).
If you're unsure, feel free to contact us for guidance or assistance.
Can we supply shaped units?
Yes, we can supply shaped units to suit your specific requirements. Whether you need arches, circles, triangles, or other custom shapes, we can manufacture units to fit your design.
What is the U Value of the unit?
The U-Value of our units varies depending on the glass type and specifications you choose. Our energy-efficient glazing is designed to meet or exceed building regulations, helping to improve insulation and reduce heat loss. Lower U-Values indicate better thermal performance, making your home more energy-efficient.
How can I achieve the best thermal performance?
To achieve the best thermal performance, choose double or triple glazing for superior insulation. Double-glazed units, with air or gas filling between the panes, reduce heat loss significantly. Opt for units filled with argon gas, as this provides better insulation compared to air. Additionally, selecting glass with a Low-E (Low Emissivity) coating can help reflect heat back into your home, improving energy efficiency. Proper installation is also key—make sure there are no gaps or drafts around the frame, as even small leaks can reduce thermal performance. Lastly, high-quality frames and seals, whether uPVC or wooden, ensure a tight fit and help maintain a consistent internal temperature.
Do we offer trade discount?
To apply for a trade discount, please fill in the form on our website, and we will contact you.
Can I pay over the telephone?
We do not accept payments over the telephone. However, you can securely pay using PayPal, Apple Pay, Google Pay, a credit/debit card, or via bank transfer.
Do we supply fixtures and fittings?
Yes, we offer a wide range of options that can be found on our website. You can browse through and find the fittings that suit your needs.
Does the online price include delivery?
Yes, our online prices include free delivery as standard. However, you can choose from different delivery options at checkout if you require a faster or more specific service.
Do we offer a guarantee?
Yes, we offer a guarantee for your peace of mind. Our units come with a 10-year guarantee when fitted in uPVC frames and a 5-year guarantee when fitted in wooden frames.
Are the units packaged?
Our vans are specially racked to transport the units securely without the need for additional packaging. This ensures safe delivery while also reducing waste and helping to protect the environment.
Is there a manufacturing tolerance?
Yes, there is a manufacturing tolerance for our units. Typically, the tolerance for the dimensions of the sealed units is ±2mm to ensure proper fit and functionality. This allows for slight variations during production and installation while maintaining the integrity and performance of the unit.
Can I amend my order?
Once your order is in production, we are unable to make changes. If you need to amend your order, please contact us as soon as possible, and we will try to assist you before it enters the production stage.
What is the return policy?
Due to the nature of the product being made to customer requirements, we do not offer a money back service should you no longer require the items after placing the order. We do, however, have a full money back guarantee on any Double Glazed Units that are not to specification or as ordered online. If you would like to apply for a refund, then please use the Contact Us form to submit your claim. We will then process any refunds within 5 working days should the units be found to either be at fault or not as ordered specification. Any units that need to be returned will be collected free within 14 working days.
Sealed Units Online reserves the right to resupply any substandard products within a 14 working day period after being notified of the issue.
Please note that we do not offer a collection service for any Double Glazed units that have not been supplied by Sealed Units Online.
Any defects or substandard Sealed Units should be reported to us within 48 hours of receipt of your order.
All refunds will be made to the original purchase method where possible. In some exceptions, we may need to ask for your bank details to make refunds that have aged with your card issuer.
What is a stepped unit?
'Stepped Units' are when one pane of the double-glazed unit is larger than the other. This creates a step that can be for several purposes. The common use for stepped units is conservatory roof units and skylight units. On conservatory roofs, this is used as a drip for water to flow into guttering and keeping moisture clear of the double-glazed seal. Another reason for a step is pictured below where it is used for skylights and allows the upper pane to be placed onto the upstands and again allowing water to drip clear of the seal and used to cover/waterproof the upstands. The website calculates your unit price based on the number of edges that require a step. Once you have placed the order, our customer service team will contact you to discuss your step requirements.
What is the difference between lead bright and lead antique?
The difference between lead bright and lead antique lies in their appearance and finish:
Lead Bright: This has a polished, shiny, and new look. It’s a bright, modern finish that creates a clean and crisp appearance, typically used for more contemporary or new-build styles.
Lead Antique: This has a weathered, aged finish that gives the leadwork a more traditional or vintage appearance. It mimics the look of lead that has naturally aged over time, creating a more classic, heritage-style effect.
Both finishes are used for decorative leaded glass designs but offer different aesthetics depending on your preference.
How do I measure Georgian bars/leads?
To measure Georgian bars or leads, please follow these steps:
Start by measuring the overall width and height of the window or sealed unit where you want to place the bars or leads. Then, measure the distance from the glass edge to the center of the lead, which will determine the placement of the bars on the glass. For evenly spaced leads, measure the distance from the center of one lead to the center of the next, both horizontally and vertically.
Additionally, if possible, provide a drawing with your measurements and a photo of the existing units, as this will assist our team in accurately planning your layout.
What is the difference between Georgian/duplex bars?
Georgian and Duplex bars are both used to create a grid or divided light effect in glazing, but they differ in their design and application:
Georgian Bars: These are the traditional bars that divide the glass into separate panes, often seen in classic or period-style windows. They are typically applied to the outside of the glass, creating a grid pattern that appears as if the window is divided into smaller sections.
Duplex Bars: Also known as "internal Georgian bars," these are placed inside the sealed unit, between the two panes of glass. The bars give the appearance of a divided window, but they are easier to clean and maintain since they don't interfere with the external surface of the glass.
Both options provide a similar aesthetic, but the key difference is where the bars are placed and how they are viewed from the outside.
What is the difference between laminated and toughened glass?
Laminated glass is made by sandwiching a plastic layer between two sheets of glass. When it breaks, the glass stays intact, preventing sharp shards and offering better safety and soundproofing. This type of glass is commonly used in car windshields.
On the other hand, toughened glass is strengthened by heating and cooling, making it more impact-resistant. When it breaks, it shatters into small, blunt pieces to prevent injury. Toughened glass is typically used in doors, shower screens, and windows.
The key difference is that laminated glass stays together when broken, while toughened glass shatters safely.