Complete Guide to E-Type Gaskets

E-type gaskets (also called E gaskets or E-type seals) are one of the most common forms of window rubber seal used in modern PVCu, aluminium and timber window and door systems across the UK. They play a vital role in keeping properties warm, weather-tight and secure, yet they are often overlooked until draughts, leaks or rattling sashes start to appear.

This guide from Window Hardware Store is designed for both professional installers and competent DIY users. It covers how E-profile gaskets work, where they are used, how to identify and measure them, and the best practice methods for cutting, fitting and maintaining them in UK windows and doors.

Throughout the guide you will find practical trade tips, notes on UK standards, and references to common hardware brands such as Yale, ERA, Mila and Avocet, to help you select and fit the correct E-type seal for your particular system.

For current product options, you can browse our dedicated E gasket product category or view specific profiles in our range of E-type gaskets.

E-profile characteristics

What is an E-type gasket?

An E-type gasket is a specific shape of window or door gasket that, when viewed in cross-section, resembles the letter “E”. The profile typically has:

A base section that pushes into a groove (also called a kerf) in the window or door frame

One or more flexible “fins” or lips that compress against the sash or rebate

A hollow or semi-hollow bulb to provide resilience and consistent compression

This shape allows the gasket to provide a continuous seal around the entire opening, even where there are minor variations in frame tolerance, hinge adjustment or installation.

E gaskets are used as part of the weatherseal system, working alongside friction stays, hinges, multi-point locks (Yale, ERA, Mila, Avocet, etc.), and glazing beads to provide an effective barrier against air and water ingress.

Materials used in E-type seals

The performance of an E-type seal depends heavily on the material from which it is made. The most common materials used in UK windows and doors are:

EPDM (Ethylene Propylene Diene Monomer) rubber – the most widely used material for external window rubber seals

TPE (Thermoplastic Elastomer) – often used in modern systems where welding or co-extrusion is required

Silicone – used in some high-performance or specialist applications, including some timber systems

EPDM is generally the preferred option for long-lasting window and door gaskets, as it offers:

Very good UV and ozone resistance (critical in south-facing facades)

Excellent weathering and temperature tolerance

Good flexibility even in cold conditions

Good resistance to many household chemicals and cleaning agents

TPE E gaskets are sometimes used where the manufacturer welds the gasket corners at the factory, or where recyclability is a key requirement. They can be softer and easier to fit, but may not always match EPDM for long-term resilience in highly exposed locations.

Typical hardness for E-type gaskets is in the range of 55–70 Shore A. Softer gaskets provide easier compression and better sealing on slightly misaligned sashes, while harder gaskets can provide improved durability in heavily used doors.

Dimensions and profile variations

Although “E gasket” is a common trade description, the actual shapes and dimensions vary considerably between systems and manufacturers. Key dimensional aspects include:

Kerf (groove) width – typically 2.5–4.5 mm on PVCu and aluminium profiles

Kerf depth – frequently 5–8 mm

Bulb height – often 5–12 mm, depending on the required compression

Fin/lip thickness – usually in the range of 0.5–2.0 mm

Small dimensional differences can have a large effect on performance. Using a gasket with too small a bulb can result in insufficient compression, leading to draughts and water leaks. Using one that is too large can make a sash difficult to close, place excess load on hinges and locks (e.g. on a Yale or ERA multi-point door lock), and may cause long-term deformation of the seal.

For this reason, professional installers always measure the old gasket and frame groove carefully before selecting a replacement from our E gasket range.

Performance functions

The primary functions of an E-type window or door gasket are:

Air sealing – reducing draughts and contributing to compliance with Approved Document L (Conservation of fuel and power) by improving overall window and door U-values

Water tightness – preventing wind-driven rain from penetrating the frame/sash interface, helping to meet performance requirements in BS 6375-1

Acoustic sealing – improving sound insulation performance, particularly around high-traffic roads or noisy environments

Dust and insect exclusion – closing small gaps that would otherwise allow fine particles or insects indoors

In security-tested products (for example, PAS 24 doors and windows fitted with ERA or Avocet high-security locking systems), the gasket helps to prevent movement and rattling that could compromise the alignment of locking points or allow manipulation.

Relevant UK standards and regulations

While E-type gaskets themselves are seldom directly specified in UK Building Regulations, they are a vital element of the overall performance of a window or door assembly. Key standards and regulations that relate to the function of E gaskets include:

Approved Document L (England and Wales) – requires doors and windows to meet specific thermal performance and airtightness criteria. Effective gaskets reduce air leakage and improve overall performance.

Approved Document F – relates to ventilation and indoor air quality. Although this covers how ventilation is provided (e.g. trickle vents), unintended draughts through failed gaskets are undesirable and may lead to non-compliance with designed ventilation strategies.

BS 6375-1 – performance of windows and doors in respect of weather tightness. Manufacturers rely on correctly specified gaskets to pass air permeability and watertightness tests.

BS EN 12365 – classification system for weatherstrips in windows and doors, covering compression, recovery and long-term performance characteristics.

When selecting replacement E-type seals, it is good practice, especially for trade installers, to use gaskets that match or exceed the performance class originally intended by the system manufacturer. Our E-type gaskets are chosen to be compatible with common UK window and door systems, supporting compliance with relevant standards.

Colour and aesthetic considerations

The majority of E gaskets in the UK are black, as this provides the best UV resistance and tends to hide dirt and minor scuffs. However, in some aluminium or timber systems, grey or white gaskets may be used to match lighter frame colours.

When replacing an E-type seal it is important to match:

Colour – especially in visible locations, such as the perimeter of contemporary aluminium windows

Surface finish – some gaskets have a smooth, shiny finish while others are more matte or textured

Profile visibility – in some systems the gasket is intentionally visible as a design feature; in others it is mostly hidden. An over-large gasket may appear unsightly if it protrudes beyond the original design lines.

Applications

PVCu windows

E gaskets are extensively used in the PVCu window market across the UK, particularly in:

Casement windows – as the primary compression seal between opening sash and outer frame

Tilt-and-turn windows – providing a continuous seal around the entire sash perimeter, working with multi-point locking gears (including those supplied via Mila or ERA)

Reversible windows – ensuring a tight seal in both normal and reversed positions

Typical locations for E-type seals in PVCu windows include:

Rebate gasket – fitted into a groove around the outer frame or sash, often on the weather side

Glazing gasket – in some systems, an E-profile seal may be used between the glazed unit and sash rebate (though wedge gaskets and flipper gaskets are also common)

When replacing an E gasket in a PVCu window, it is crucial to match the original profile. Many profile extruders (such as Liniar, Rehau, Eurocell and others) use proprietary gasket designs. Our E gasket range includes profiles compatible with numerous UK PVCu systems; trade users often keep sample offcuts to visually match the shape before ordering.

PVCu doors and French doors

Front doors, back doors, French doors and some sliding patio doors use E-type gaskets around the leaf and/or frame. The door gasket must:

Provide sufficient compression to prevent draughts and water ingress

Allow the door to latch smoothly without excessive force

Accommodate the operation of multi-point locks from brands such as Yale, ERA, Avocet and Mila

E-profile door gaskets are often slightly larger or firmer than those used in windows, due to higher usage and greater door size. When replacing a door gasket, check for:

Wear marks where the leaf meets keeps and striker plates

Areas of flattening at the bottom threshold, particularly on high-traffic doors

Damage caused by pets, furniture or misaligned hinges

Correct gasket selection can significantly improve the feel of a door when closing and locking, as the compression interacts with the locking hooks/bolts and keeps. Over-thick E-type seals can cause difficulty engaging the final compression on a multi-point lock, particularly on older doors with worn hinges.

Aluminium windows and doors

Modern aluminium systems often use carefully engineered E-type and bubble gaskets in multiple planes to achieve very high weather and acoustic performance standards. These may be used:

Between sash and frame as a primary compression seal

Between sash and glazing unit

At the interface between frame and capping profiles

In aluminium systems, tolerances are tighter and the gasket choice is critical. Many systems use co-extruded gaskets or specific designs that form part of a tested system, for example under BS 6375-1 testing. Where possible, use manufacturer-approved replacements, or carefully match the profile from our E-type gaskets range, ensuring:

Kerf fit is exact, to avoid the seal loosening over time

Bulb height and shape allow the sash to close fully on all locking points

Material is suitable for potential temperature extremes experienced by aluminium frames in direct sunlight

Timber windows and doors

Traditional timber windows often relied on brush seals or simple draught strips. However, most modern timber casement and tilt-and-turn windows, as well as high-performance timber doors, now use compression gaskets similar to those found in PVCu and aluminium systems.

E-type seals in timber frames may be:

Fitted into a machined groove around the sash or frame

Stapled or pinned (less common on higher-end systems)

Used in conjunction with surface-mounted weatherstripping in heritage refurbishments

When replacing gaskets in timber frames, take extra care when removing old seals to avoid damaging the groove. Timber moves with humidity and seasons, so a slightly softer E gasket (lower Shore A hardness) can be beneficial to maintain a consistent seal throughout the year.

Composite and fire-rated doors

Many composite doors use E-type gaskets as the main door gasket, particularly around the perimeter of the door leaf. In some FD30 fire doorsets and smoke control doors, intumescent and smoke seals may also have an E-like profile.

Important considerations:

Do not replace a fire door’s seal with a non-approved product; always follow the doorset manufacturer’s specification

Smoke seals often need specific compression characteristics to pass BS 476 or BS EN 1634 tests

On non-fire-rated composite doors, you can usually treat the perimeter gasket similarly to PVCu door gaskets, following the measuring and fitting guidance in this guide

If in doubt, consult the doorset data sheet or speak to our technical team before selecting a replacement door gasket from our E gasket collection.

Retrofit and refurbishment applications

For both trade and DIY customers, replacing tired, flattened, or perished window rubber seals is one of the most cost-effective ways to:

Improve energy efficiency by reducing air leakage

Remove annoying draughts and whistling noises

Stop minor water ingress and staining around frames

Improve acoustic performance in noisy areas

In retrofits you will typically:

Remove the existing E gasket carefully

Measure the profile and groove (see “Measuring and cutting” section)

Order matching or compatible E-type seals from our E-type gaskets range

Fit the new gasket and re-adjust sashes/hinges as required

This process is particularly popular among landlords, facilities managers and homeowners looking to improve older PVCu windows without replacing the entire unit, especially where the hardware (Mila hinges, ERA espags, etc.) is still in good working order.

Measuring and cutting

Tools required

Whether you are a trade installer or a DIY user, having the right tools will make measuring and cutting E gaskets significantly easier and more accurate. Useful tools include:

Steel rule (at least 300 mm) – for basic length and depth measurement

Vernier caliper (digital or manual) – for accurately measuring gasket and groove dimensions to 0.1 mm

Sharp utility knife or side cutters – for clean, square cuts on gaskets

Scissors – for fine trimming where needed

Marker pen – to mark cut points

Measuring tape – for overall sash and frame perimeter measurements

For trade users, a small sample board or labelled bag system for storing offcuts of existing gaskets can be invaluable when identifying replacement profiles on future jobs.

Removing the old gasket

Before you can measure or replace an E-type seal, you need to remove a representative sample of the existing gasket.

Open the window or door fully to gain access to the seal

Choose a section that is relatively undamaged and not excessively stretched (usually near the hinge side is best)

Gently pull the gasket from the groove, starting at the corner and working along the length

If it is stuck, use a plastic scraper or a blunt tool to ease it out; avoid using sharp metal tools that may damage the frame

Take at least 100–150 mm of gasket as a sample. If the gasket has shrunk over time (common in older EPDM seals), you may see gaps at the corners; in that case, choose a piece that still shows its original cross-sectional shape.

Measuring the gasket profile

Once you have a sample, use a vernier caliper or steel rule to measure:

Bulb height (overall height of the sealing part) – typically 6–12 mm

Bulb width – often 3–8 mm

Base width (the part that sits in the groove) – commonly 2.5–4.5 mm

Overall depth of the profile – from the back of the base to the outermost point of the bulb

Any fin or lip thickness and length – these may be 0.5–2.0 mm thick and extend a few millimetres from the main bulb

Record these measurements to the nearest 0.5 mm. Where possible, compare the sample visually against product photos and technical drawings in our E gasket category.

Trade tip: lay the gasket sample on white paper and lightly press it flat with a piece of glass or clear plastic while measuring. This helps you see the profile shape more clearly, particularly if the original gasket has taken a set over time.

Measuring the frame groove (kerf)

The groove into which the E gasket fits is just as important as the gasket size itself. A poorly fitting base can cause:

Gaskets that pull out when the window is cleaned

Twisting or rolling of the seal when the sash is closed

Poor long-term stability and performance

With the old gasket removed (in at least one area), measure:

Groove width – this is the critical dimension; measure in several places (top, sides, bottom) as PVCu can distort slightly

Groove depth – from the visible edge to the back of the groove

Any undercut or barb that might hold the gasket in place

Typical groove widths for PVCu and aluminium systems are:

2.5–3.0 mm – smaller, tighter-fit systems

3.0–3.5 mm – common for many mainstream profiles

3.5–4.5 mm – larger, more robust gaskets

If your old gasket is missing or deteriorated beyond recognition, the groove measurement will be your primary guide in choosing a compatible E-type seal.

Calculating required compression

The performance of an E-type gasket depends on obtaining the right amount of compression when the sash or door is closed. As a general rule:

Aim for 25–35% compression of the gasket bulb

Less than 20% may allow draughts and leaks

More than 40% can make closing difficult and may quickly fatigue the gasket

To estimate this, measure:

The “gap” between the closed sash and frame (without the gasket, if possible, on a test section)

The uncompressed bulb height of your chosen E gasket

For example:

If the measured gap is 8 mm and you select a gasket with a 10 mm bulb, the compression will be (10 – 8) / 10 = 20% – on the low side, but often acceptable in low-exposure locations

If the measured gap is 8 mm and the bulb is 12 mm, compression is (12 – 8) / 12 = 33% – ideal in many circumstances

Professional installers often use experience and feel: once fitted, a sash should close smoothly on its locking points (Yale or ERA espagnolette, for example) without excessive handle force, but still offer firm resistance as the gasket compresses.

Measuring length for replacement gaskets

When ordering or cutting lengths of E-type gasket, allow for both perimeter length and corner treatment.

Measure the full internal perimeter of the frame or sash where the gasket will sit

Add at least 50–100 mm per window or door to allow for trimming and waste

For example, for a typical PVCu casement window of 900 mm wide x 1200 mm high:

Perimeter = (900 + 1200) x 2 = 4,200 mm

Allow an additional 100–150 mm

Order or cut at least 4,300–4,400 mm of gasket

If you are replacing gaskets on multiple windows, it is often more economical to purchase a continuous coil (e.g. 25 m or 50 m) from our E gasket range and cut to length on site.

Cutting techniques

Clean, square cuts are essential for reliable gasket performance, especially at the corners. Poorly cut ends can create gaps that lead to draughts and water ingress.

Use a sharp utility knife or side cutters

Cut on a solid, flat surface – a cutting board or timber offcut works well

Mark the length with a fine marker pen before cutting

Always cut slightly longer than needed; you can trim back for a perfect fit

Corner joints can be:

Butt joints – two square-cut ends meeting in the corner; simplest and common on PVCu windows

Mitred joints – 45° cuts that meet neatly; often used in visible areas on aluminium or timber frames

For DIY users, butt joints are usually easier to achieve consistently. Make sure the ends are tightly compressed together when fitted, with no visible gaps.

Fitting techniques

Preparation before installation

Proper preparation of the frame or sash is essential for a long-lasting, high-performance seal.

Remove all remnants of the old gasket from the groove

Use a soft brush or vacuum cleaner to clear dust and debris

Wipe the groove with a mild detergent solution and a lint-free cloth

For stubborn dirt, use isopropyl alcohol (IPA) on PVCu and aluminium, testing a small area first

Ensure the groove is fully dry before fitting the new gasket

Check the condition of the surrounding hardware:

Hinges (e.g. Mila friction stays, Avocet butt hinges) – check for wear or play

Locks and keeps (ERA, Yale, etc.) – confirm they engage smoothly

Sash alignment – misaligned sashes can overload new gaskets and reduce performance

Trade tip: It is often worth making minor hinge and keep adjustments after fitting the new gasket, to optimise compression and closing effort. This is particularly important on heavy doors and tilt-and-turn windows.

Starting the installation

Most E gaskets are “push-in” types designed to be fitted by hand.

Begin at the hinge side of the sash or frame (for a casement or door), or at the bottom for tilt-and-turns

Push the base of the gasket firmly into the groove using your fingers or a blunt plastic tool

Work along the length, ensuring the gasket is fully seated and not twisted

Do not stretch the gasket as you install it. Stretching may seem to help it go round corners, but it will often lead to shrinkage over time, especially at the corners where gaps may open.

Corners and joint treatment

How you handle corners is critical to the performance of the E-type seal.

For butt joints – cut each length so the ends meet tightly in the corner. Start by fitting full lengths along each side, then trim the ends gradually to achieve a snug fit.

For mitred joints – cut each corner at 45° using a mitre block where possible. Press the two mitred ends together to form a neat, continuous junction.

On some PVCu systems, the gasket is fitted continuously around all four sides without a joint (particularly on smaller sashes). In this case:

Start at the bottom centre

Work around all four sides, gently pushing the gasket into the groove without stretching

Return to the starting point and cut so that the ends meet with a slight compression

This continuous method can reduce the risk of water or air leakage at corners, but requires careful handling to avoid stretching.

Lubrication and ease of fitting

On tight or complex profiles, a small amount of lubricant can make fitting easier.

Use a silicone-based spray lubricant sparingly on the gasket base only

Avoid petroleum-based products that can attack EPDM rubber

Wipe any overspray from visible frame surfaces with a clean cloth

For DIY users, a light application of silicone spray can also help new door gaskets to bed in, reducing friction and making it easier to latch and lock the door during the first few weeks.

Checking operation after fitting

Once the new E-type seal is fitted, test the window or door thoroughly.

Close the sash slowly and check for resistance – it should compress smoothly without the need for excessive force

Operate the locking handle (Yale, ERA, Mila, etc.) several times to ensure it engages fully on all locking points

Check that the sash sits evenly all round, with consistent gasket contact

If the sash is difficult to close or lock:

Check the gasket is fully pushed into the groove

Look for areas where the gasket may be doubled over or twisted

Consider a minor hinge adjustment to relieve pressure on the heavily compressed side

If the gasket bulb is obviously over-large for the gap, review your gasket selection

Balancing compression on multi-point locks

On modern doors and larger windows with multi-point locks (from brands such as ERA, Avocet, Yale and Mila), achieving an even gasket compression is vital.

Close the door and engage the lock fully

Check the contact between gasket and frame all around the perimeter

If some areas appear lightly compressed while others are over-tight, adjust the keeps (striker plates) where possible

Many keeps feature eccentric cams or adjustable plates; turning these can increase or decrease the compression on the E gasket. This allows you to balance:

The force required on the handle

The tightness of the weatherseal

The smooth operation of hooks, rollers and deadbolts

Trade tip: it’s often best to set top and bottom keeps first, then fine-tune the intermediate keeps. On doors exposed to strong prevailing winds, a slightly higher compression on the weather-facing side can help improve performance.

Special considerations for sliding and tilt-and-turn systems

Sliding doors and tilt-and-turn windows place different demands on E-type gaskets.

Sliding patio doors – gaskets may be subject to more movement and potential contamination from debris in the track. Ensure the seal runs continuously and does not catch in corners or on any interlocks.

Tilt-and-turn windows – the sash moves in two planes (tilt and turn). Gasket compression must be sufficient in both modes, so use care when selecting replacement profiles, and always test both operations thoroughly after fitting.

In both cases, keep the track and sealing surfaces clean and free of grit, as abrasion can quickly damage the gasket lips and bulbs.

Adhesive fixing (where appropriate)

Most modern E gaskets are designed to be mechanically held in a groove without adhesive. However, in some refurbishment situations (especially on older timber or non-standard frames), you may need to secure the gasket with a suitable adhesive.

Use only adhesives that are compatible with EPDM or TPE rubber and with the frame material

Apply sparingly within the groove; excess adhesive can squeeze out and interfere with gasket compression

Do not use solvent-based adhesives that may dissolve or swell the gasket or PVCu frame

Always check manufacturer guidance; if in doubt, seek advice before gluing any door gasket or window rubber seal in place.

Maintenance tips

Routine inspection

Even high-quality E-type gaskets will slowly age over time. Regular inspection helps identify minor issues before they become major problems.

Check seals annually at a minimum; twice a year is ideal (spring and autumn)

Look for cracks, splits or hardening of the rubber

Check for gaps at the corners where gasket shrinkage may have occurred

Inspect areas of heavy use, such as at handle height on doors and windows

On commercial premises, where doors may be used hundreds of times a day, more frequent checks are advisable, especially on main entrance doors with heavy closers and strong compression.

Cleaning E gaskets

Keeping the gasket and surrounding frame surfaces clean helps preserve the material and maintain sealing performance.

Use a mild detergent solution (e.g. diluted washing-up liquid) and a soft cloth or sponge

Rinse with clean water and dry with a lint-free cloth

Avoid abrasive pads or harsh solvents, which can damage the EPDM surface

For PVCu and aluminium frames, general window frame cleaners are usually safe, but always test on a small, inconspicuous area first. Do not allow strong solvents (like cellulose thinners or acetone) to come into prolonged contact with the gasket, as they may cause swelling or softening.

Lubrication and conditioning

In high-use locations or harsh climates, applying a suitable conditioning product can extend the life of an E-type seal.

Use a silicone-based spray or wipe specifically intended for rubber seals

Apply sparingly along the length of the gasket

Wipe away any excess with a clean cloth

This helps to:

Maintain flexibility, particularly in cold weather

Reduce sticking between gasket and frame/sash surfaces

Prevent squeaking or “stiction” when opening doors and windows

On sliding patio doors, a periodic application of silicone to the gasket and interlock seals can help maintain smooth operation.

Dealing with common problems

The most frequent issues associated with E-type gaskets can usually be traced to ageing, incorrect selection, poor fitting, or frame/hardware movement over time.

Draughts and air leakage

If you feel cold draughts around windows or doors:

Check gasket continuity – look for gaps, particularly in corners and at mid-joints

Inspect for flattening of the bulb, especially on the bottom of doors and windows

Examine hinge and lock adjustment – a poorly aligned sash may not compress the gasket sufficiently

Solutions include:

Replacing worn or flattened gaskets with new E-type seals from our E-type gaskets collection

Re-adjusting hinges (Mila, Avocet, etc.) and keeps to improve compression

Fitting a slightly larger bulb profile if the gap has increased due to frame movement – but avoid over-compression

Water ingress and staining

Water leaks around frames may appear as:

Damp patches or staining on internal reveals

Water collecting on cills or thresholds

Drips from the head of the frame during heavy rain

Check:

That the gasket is continuous and fully seated

Weep holes and drainage channels are clear of debris

External seals and mastic joints are intact

If the E gasket has perished, cracked or shrunk, replacing it is often the quickest and most effective remedy. Always ensure that any new gasket is compatible with the window or door system and provides appropriate compression under BS 6375-1 style weather conditions (exposure to wind-driven rain).

Sticking or difficult-to-close doors

After fitting a new door gasket, or on doors where the seal has swollen due to moisture or incompatible chemicals, you might find the door difficult to close or lock.

Check for over-sized gasket – confirm the bulb height relative to the actual gap

Ensure the gasket is not doubled over or twisted in any sections

Adjust hinges and keeps to relieve excessive pressure, especially around the lock points

If the problem persists, consider using a slightly smaller bulb E-type seal from our E gasket selection. It is better to have a slightly softer, smaller gasket that allows the door to close properly than a large bulb that prevents proper locking and may stress the hardware (Yale or ERA locks, for example).

Noise and acoustic issues

Where external noise is a problem, a well-fitted, continuous E-type gasket is crucial to achieving good acoustic performance.

Check for any visible gaps around the frame

Look for inconsistent compression, where parts of the gasket are not fully in contact with the sash or door leaf

Verify that trickle vents and other intentional ventilation openings are correctly closed when noise reduction is required

In some cases, upgrading to a slightly larger or denser gasket profile can improve acoustic sealing, provided it does not adversely affect operation. A balanced approach is necessary to comply with Approved Document F ventilation requirements while improving comfort.

Mould or discolouration

Black spots or mould on gaskets usually indicate prolonged moisture or condensation, sometimes combined with poor ventilation.

Clean the gasket and frame thoroughly with a mild detergent

If necessary, use a gentle mould remover suitable for rubber and PVCu (test first)

Review room ventilation – ensure extract fans and trickle vents are used appropriately

Long-term exposure to mould can degrade gasket materials. If the seal has become sticky, brittle or degraded in areas affected by mould, replacement is advisable.

When to replace E-type gaskets

No gasket lasts forever. Typical lifespans vary depending on:

Material (EPDM usually outperforms basic TPE in harsh conditions)

Exposure (south-facing, coastal or industrial environments are more demanding)

Usage frequency (main entrance doors vs rarely used windows)

As a general guide, consider replacement when:

The gasket is visibly cracked, split, or severely flattened

There are persistent draughts or leaks even after hinge and keep adjustments

The gasket has shrunk away from corners, leaving visible gaps

The rubber feels hard, brittle or sticky to the touch

Replacing E-type gaskets is relatively quick and inexpensive compared with full window or door replacement, and can restore much of the original performance of the installation. Many trade users schedule gasket replacement as part of larger refurbishment projects, combining it with hardware upgrades (e.g. new ERA or Yale locks) for a comprehensive improvement.

Stocking and handling for trade users

For installers, maintenance contractors and fabricators, managing gasket stock correctly ensures consistent results on site.

Store gasket coils in a cool, dry place away from direct sunlight

Avoid kinking or sharply bending the gasket, which can cause permanent deformation

Label coils clearly with profile code, manufacturer reference and typical applications

Keep sample boards or labelled offcuts to aid in identifying compatible replacement profiles

When transporting gaskets to site:

Protect them from sharp edges or tools that might cut or nick the sealing surface

Do not store heavy items on top of gasket coils

Good handling practice will keep E-type gaskets in optimal condition until they are installed, ensuring the best possible long-term sealing performance for your customers.

For specific profile identification, technical data, and trade pricing, visit our E gasket category or contact Window Hardware Store for assistance in selecting the right E-type seal for your windows and doors.