When you intend to build or make alterations to your home, you must ensure that the improvements are safe. For example, building new doors or windows is one of the most frequent alterations. Therefore, before beginning any work, you should get your property inspected to verify that the changes are safe.
You can’t just start tearing down walls without ensuring that the building site is ready for alterations. You call structures designed to sustain the original building load-bearing structures. You can jeopardize lintels, or load-bearing structures when you install a new door or window. If the structure is sufficiently weakened due to the alteration, the supporting structures may start to crack and even collapse.
Are you building a structure and don’t know what a steel lintel is? Then, let’s read further to discover the fundamentals and their significance.
What Is a Lintel
A lintel is a beam that spans openings in structures such as windows and doors and other openings to sustain the weight of the building above. The lintel beam’s width equals the wall’s width, and its ends are built into the wall. Lintels are categorized according to the material used in their construction.
In comparison to arches, horizontal lintels are simpler to build.
Lintels are most often made of wood, concrete or steel.
Timber is inexpensive, widely accessible, and quickly cut to size on site. It is, nevertheless, best suited to smaller gaps with modest load carrying.
Precast Concrete Lintels
Precast concrete lintels are cost-effective and offer enough support for brickwork above window and door openings. In addition, you can finish precast concrete lintels with a variety of surface treatments.
What Is a Steel Lintel?
Steel lintels are typically composed of pre-galvanized steel that has been cut and rolled or pressed into the desired shape.
Steel lintels have a benefit over concrete lintels in that they are often lighter and easier to handle at the site.
Steel is also adaptable, and it may be custom-made to fit a particular construction need, whether it’s arched, a corner, or creating a bay window, for example.
For every building project, it is essential to specify the right lintel. To help you better understand what kind of lintel you need with what project, we have described the correct application for each below.
Steel Lintel for Masonry Cavity Walls
Cavity wall building using masonry is the most prevalent kind of construction in the United Kingdom. An air cavity between the inner and outer leaves of brickwork may be completely or partly filled with thermal insulation depending on the use. Cavity walls need structural support for each brickwork leaf that is exposed via an opening.
The hollow wall’s build-up defines the specification for a cavity lintel, the size of the hole the lintel must bridge, and the load imposed by the building above. UKLintels offer a comprehensive line of steel lintels for ordinary and heavy-duty applications.
All cavity lintels have integrated insulation to assist minimize the steel’s thermally bridging effect. Cavity wall lintels are also available to suit Wide Inner Leaf and Wide Outer Leaf applications and are available from 50mm to 150mm cavity sizes.
Steel Lintels for Solid Outside Walls
The size of the opening that the lintel must span and the weight imposed by the building above define the lintel specifics. UKLintels provides two kinds of steel lintel for exterior solid walls, each with choices for normal and heavyweight loading situations.
1. Box Style Lintels
The hollowed rectangular shape of Box Lintels is placed as part of the masonry’s inner skin. A protruding toe lies over the outer ‘skin,’ supporting the wall build-up in that area. If thermal insulation is being used in the wall, a box lintel with integrated insulation may assist in minimizing the effect of the steel on the total loss of heat through the wall.
2. Inverted T-Shaped Lintels
They’re precisely what they sound like: a foundation plate that covers the whole width of the wall and holds the brickwork. A central plate provides the lintel strength and lies in the middle of the wall structure. It lies in between the 2 brickwork skins, perpendicular to the centre of the lintel’s bottom. UKLintels also offer a heavy duty version of this lintel which is two ‘C’ section lintels spot welded back to back that work in the same way. These lintels are mostly used for fairfaced brickwork with two separate leaved of a 215mm fairfaced brick wall. Insulation that is built into the structure is not a choice.
Steel Lintels for Inside Solid Walls
Steel lintels for solid interior walls are a low-cost option that offers a good combination of weight, strength, and resilience. There are various lintel designs available to meet diverse applications and load situations. These would be corrugated lintels, channel lintels and box lintels and are available to suit a 100mm wide wall or 140mm wide wall.
Steel Lintels for Closed Eaves
Closed eaves lintels offer structural support above gaps above a brick cavity wall, where the pitched roof meets the brick cavity wall. It distributes the weight of the roof and ensures that it can withhold the roof’s total weight.
Closed eaves lintels vary from brick cavity wall lintels in that no outside leaf masonry is constructed from the front toe.
This enables the inside leaf bricks to continue, and the brickwork must be completed with a continuous wood wall plate. With the lintel, the last phase of blocks and the wall plate provide the stated strength properties.
Thermal bridging occurs when insulation is not continuous between exterior walls and pitched roofs. To maintain the thermal envelope, lintels for closed eaves applications have integrated insulation.
Steel Lintels for Timber Frame Building
External framed walls made of timber are becoming more common for lighter weight, watertight, and thermally efficient structures. Steel lintel systems for wood-framed walls are lightweight, practical, and strong.
Lintels attach to the frame structure using restraining clips and a batten. You either screw or nail the clips (supplied with the lintel). With this restriction, the frame and outside leaf will not flex during assembly, attaining the stated loading values.
Timber frame lintels must also be properly supported during installation.
Steel lintels for single skin external solid walls
Designed to support a single skin of masonry wall in either brickwork, blockwork or stone. These lintels are either 100mm, 120mm or 137mm wide and vary in height as the lintel lengths increases.
Extreme Load Lintel
Designed to be used for extreme loading conditions or when the permissible deflection on a lintel needs to be reduced or eliminated. This is why these lintels are often used for bi-folding doors or for larger clear span openings. The wide bottom plate manufactured from 6mm steel and galvanized to BS EN1461 gives this style of lintel complete flexibility as it can be used for cavity wall construction, wide inner leaf, wide outer leaf or solid wall openings such are wide span double or triple garage door openings.
Thermally efficient lintels
Catnic’s unique design enables a complete thermal break between the inner and outer leaf of the cavity wall construction. The Catnic TBL range offers a practical solution to the latest changes in Building Regulations offering the most thermally efficient steel lintel solution on the market. UKLintels are the largest stockist of Catnic’s pioneering lintel and stock every cavity size and profile available.
Give It the Support It Needs!
Steel lintels are all built to withstand a specified safe operating load. If you don’t know how to calculate these weights or proportions you must seek advise from a qualified structural engineer or your builder prior to purchase. Alternatively, contact us, and a member of our sales team will be happy to assist you!
Folding doors used to mean cheap MDF panels that constantly jumped the track. But today’s bi-fold doors provide an elegant and functional way to make your living space more flexible.
Because the door panels fold and stack as the doors are opened, you can turn a wall into a large opening. But since this means the wall goes away, proper support across the top of the opening is crucial to hold the doors in place when closed and keep the roof from falling in when open.
The horizontal beam or lintel running across the top of the door jam provides that structural support. While the lintel can have some give or flex for standard doors and windows, it needs to maintain its straight line for bi-fold doors to function properly.
Let’s take a look at what makes a lintel for a bi-fold door different and how to choose the proper one.
Types of Lintels
Lintels are found above all the doors and windows of a house, with different types called for depending on the size of the opening and the amount of load. They hold up the upper floors and roof where there is no wall to do so.
Here’s a quick look at your choices:
- Stone – used for openings up to 2m wide
- Brick – used for openings less than 1m wide with smaller loads
- Wood – usually found in older homes and used for openings with more length
- Reinforced concrete – appropriate for all loads and sizes
- Reinforced brick – used for heavy loads and openings at least 1m wide
- Steel – best for large openings that are subject to heavy loads
Which Lintel for Bi-fold Doors?
Normal structural loads in a building come from the roof trusses, exterior masonry, and floor joists. Your choice of lintel has to take into account the amount of load. For bi-fold doors, you have an additional load as the lintel has to be able to support the additional weight of the doors when they are closed.
Most exterior openings use lintels of concrete, wood, or steel. Because even a small bend can keep your doors from sliding open or shut. This is known as permissible deflection for lintels and most bi-fold door manufacturers would request that a lintel is installed with a maximum deflection of less than 5mm. A Lintel should not exceed a maximum vertical deflection of 0.003 x the effective span (effective span = distance between centre of bearings) when subjected to the safe working load (SWL). heavy-duty steel is recommended for bi-fold doors, especially for large openings.
As a minimum we would recommend looking at our Extra Heavy Duty Range. In most circumstances we would recommend using our CXL Lintels (Extreme Load Lintel) (the links take you to a 50-65mm cavity lintel, please select the cavity size required from the dropdown box). CXL Extreme load lintels offer the minimum deflection in our lintel range. These are in stock up to 6.0m long in every cavity size (50,60,70,90,110,130,150mm).
Below is a table of loadings that these lintels can achieve. To achieve the loading figures shown, the lintel must be laterally restrained and have 200mm end bearing supports and inner to outer load ratios between 5:1 and 19:1. Please consult a structural engineer to check the product suitability and deflection for your project prior to ordering.
Bi-fold doors add dramatic flair to your space along with flexibility. Added to an exterior wall, these doors can extend a living room into the patio. Added to an internal wall, they allow separate rooms to turn into a single larger space when needed.
But adding a bi-fold door requires more considerations than a standard opening. The installation has to take into account the thickness of the walls and the size of the opening. Your choice of lintel must also consider the weight of the door, the type of masonry above the door, and how much masonry is on either side of the opening. Loading ratios should also be taken into consideration. Safe working loads (SWL) as defined by BS 5977:Part 2: 1983 for cavity wall lintels refer to uniform distributed loads applied in the inner to outer leaf ratios:
- 1:1 for lintels supporting masonry only
- 3:1 for lintels normally carrying timber floors
- 5:1 for lintels normally carrying concrete floors
- 19:1 for lintels normally carrying non standard or unusual load conditions.
Your choice of a door should also be taken into consideration. Top-running doors put more load on the lintel than bottom-running doors, which get more support from the floor.
For this reason, there can be a lot of math involved in choosing the right type and size for your new bi-fold door, which is where a structural engineer comes in. The larger the size or the more the new door will vary from the old, the more helpful it can be to have a professional work with you to ensure you have adequate structural support.
Size, load, and movement have the most impact on choice and installation. Size is simply figured by measuring the size of your opening and adding at least 150mm to each end for support (200mm for CXL profiles). Going beyond that delivers extra cost more than it does extra support.
Whether you plan to replace an existing door or add in a new feature, installation starts by calculating how much support your doors will need. A steel lintel is a safe bet to handle the weight of your door and the load of the above structure.
Bi-fold doors can be placed on an interior or exterior wall and even added to a load-bearing wall. Opening up a load-bearing wall to add a door can weaken it as there is less to support the weight of the upstairs floors and the roof. A rolled steel lintel can provide the extra support that ensures the wall won’t collapse under the weight.
Proper installation should involve bedding the lintel in the mortar and placed perfectly level. Both are important to ensure the load is evenly distributed. Mortar should be cured adequately to ensure the load is transferred through the lintel to the walls on either side of the door.
Installing a Bi-fold Door?
Bi-fold doors open your home to more light and add flexibility to your interior layout. Installing them requires adding a lintel across the top to provide structure to the opening and support the weight of the doors. For bi-fold doors, steel lintels make your best option as they have the strength for the job.
If you’re adding bi-fold doors for a client, contact us for a quotation. We offer the UK’s largest steel lintel range with fast track and next-day delivery nationwide.
Please always consult a structural engineer to check any product suitability prior to purchasing from our website as some items are non-returnable once purchased. A lack of due-diligence can result in an expensive mistake. We always recommend full due-diligence is taken prior to ordering.
We’ve been using lintels in the UK for thousands of years. You only need to take a trip to Stonehenge to see a perfect example of post-and-lintel construction that dates back as far as 2500 BC.
Today lintels are still an integral part of our buildings and homes.
When installing a lintel, you need to be sure that it’s done right. If not, it can lead to serious complications.
If you want to know how to start installing a lintel, read on as we look at the basic steps involved.
What Is a Lintel?
A lintel is a beam that is used above the openings for doors or windows in order to support the weight of the structure above.
Without a lintel, the entire load of the brickwork about a door or window would have to be carried by the window or door frame itself. A lintel spreads that load into the masonry on either side of the door or window, ensuring that door and window frames aren’t placed under undue pressure.
A lintel must be properly installed in order to function correctly.
Steps to installing a Lintel
Proper lintel installation requires numerous steps. We’ll take a look at some of the basics below.
Minimum End Bearing
In order for a lintel to provide the correct support, it needs to extend far enough onto the brickwork at the side of the door or window.
The lintel should normally extend a minimum of 150mm beyond the opening on either side although down to 100mm is permissible under certain circumstances (check with the supplier or manufacturer if you need a reduced bearing). It’s not advisable to extend too far beyond this as you’ll be paying for more than you need.
Bedded on Mortar
You must bed your lintel on mortar.
By installing a lintel on a bed of mortar, it ensures that the loads are evenly distributed. The thickness of the mortar should be sufficient to accommodate any unevenness that there might be between the lintel and the support.
The lintel should be bedded on both leaves to ensure that load is spread symmetrically.
Make Sure the Lintel is Level
Once you’ve placed the lintel on the bed of mortar, you need to ensure that it’s perfectly level. If the lintel isn’t level, the load will not be evenly distributed and may place undue stress on parts of the supporting walls.
Use a spirit level to ensure that lintel is placed perfectly horizontally across the opening. You’ll also need to confirm that the lintel is level cross-wise too; in other words, you should confirm that neither leaf is higher than the other. If this is the case, it will put undue pressure on one of the leaves.
Allow Mortar to Cure Before Applying Loads
Once your lintel is level, you’ll need to allow the mortar to cure before applying any loads.
Until the mortar is completely cured, the load won’t be correctly transferred through the lintel and into the masonry on either side of the opening. If you’re in a rush and can’t wait for the mortar to cure, then you must ensure you place appropriate supports beneath the lintel before applying any loads.
Lay Bricks on Both Sides
Once the mortar is dry, or you have supports in place, you can start laying bricks.
You must ensure that you lay bricks on both sides simultaneously so that the load on each leaf does not get too far out of balance. In other words, once you’ve laid one or two rows of bricks on one side, you should stop and lay the same amount on the other side. You’ll need to repeat this process to ensure that the load is always the same or similar on each leaf.
If you put too much load on one side at once, you may damage the lintel or have an even worse problem. Don’t take the risk and always keep the loads on each leaf balanced.
Install a Damp Proof Course if Necessary
If the lintel is being installed as part of a cavity wall, then you should install a damp proof course.
Cavity walls are designed such that the outer leaf is intended to be damp, and the inner leaf dry, with the cavity ensuring that this remains the case. That’s why anything that bridges this cavity—such as a lintel—should be installed such that moisture doesn’t track between the two.
BS 8215 states that DPCs in masonry buildings should have a minimal fall of 150mm. This should be sufficient to prevent any moisture tracking inwards.
Some lintels will need to be propped until the mortar in the supported masonry has cured. This will normally be the case for “channel” lintels (those with a “C” shaped portion to one or both leaves) where the masonry built into the channel contributes to the strength of the lintel.
Where this is the case, the manufacturer will normally provide guidance in the form of a label applied to the lintel or give guidance within their technical literature. Please always check prior to installation if you are unsure.
Whilst not required, propping can also be beneficial for other lintels. Allowing the mortar to cure whilst propped will reduce the deflection of the lintel, which could be particularly noticeable for longer openings.
Key takeaways and guideance on installing a Lintel
Installation should always be in line with the manufacturer’s guidelines. If you are in doubt as to the structural performance or suitability of a lintel then please contact the manufacturers technical department before ordering/installation.
- Each lintel is different but most steel lintels should be propped at 1.2m ctrs and not removed until the mortar has cured.
- Minimum recommended end bearing = 150mm. The lintel should be bedded on mortar and levelled both along the lintel and across its width. Full bricks, blocks or padstonesshould be used as bearing areas. Do not bear onto cut blocks.
- All external wall lintels MUST be installed with a flexible damp proof course (DPC) or cavity tray. In the case of cavity walls the cavity tray should extend not less than 50mm beyond the cavity return.
- Inner and outer leaves supported by lintels should be raised together to avoid excessive eccentricity of loading.
- Masonry must not overhand any flange by more than 25mm.
- Masonry above the lintel should be allowed to cure before applying floor or roof loads.
Further guidance can be found in the manufacturer’s literature at Catnic or Stressline.
Are You Looking for High-Quality Lintels?
If you’re looking to purchase Stressline galvanized or Catnic lintels, then you’re in the right place.
We offer a wide range of products, with every cavity size in standard duty, heavy-duty, and extra-heavy-duty profiles. If you’re looking for an extreme load lintel, we’ve got you covered too. We are the only UK stockist to carry a full range of extreme load lintels from all the major brands.
Check out our range of products today.
Catnic has increased its prices for the second time in 2021 after its initial 15% price increase on 1st April. Their full price list is available to view here.
The new price list sees an 18% increase in prices due to constrained supplies which we wrote about in our recent article. All steel lintel manufacturers have also moved to very similar amounts which significantly increases the cost of lintels to the end-user for 2021 and beyond.
With demand at an all time high, and supply being limited by the reduction in availability of raw materials we could even see an unprecedented 3rd increase later in 2021.
Stay updated on market changes
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For anyone working in the construction sector, the global shortage of construction supplies (steel included) has proved challenging over the last few months. The continued supply constraints have seen manufacturers introduce quotas, effectively rationing the available supply of lintels to UK construction firms and DIY buyers.
The BBC reported just this week the Office for National Statistics projection of an 8% increase in material prices and a global shortage of steel as demand exceeds supply.
Continued supply available to our customers
At UK Lintels, we’re fortunate to be the UK’s largest single site stockists of Catnic and galvanized lintels and were well prepared for the shortages. With a generous stock holding and our two acre Bristol depot, we have been able to continue serving our customers despite the challenges.
Even as material shortages persist in our industry, we have over 5000 Catnic and Stressline steel lintels in stock with a value of over £4m at current list prices.
Planning for future lintel supply constraints
In order to continue serving our customers, we are recieving two artic lorry deliveries per week, with 87 tonnes of Stressline and Catnic steel lintels secured in forward orders which are due in stock over the next four weeks.
Between August and October we plan on adding an additional £1m in stock and our buyers are working tirelessly to secure additional contracts with our supply partners.
With continued uncertainty and volatility in supply likely to continue for a time to come, subscribe to our mailing list to receive regular updates on availability, offers and sector news and information.
For our range of steel lintels, click here or speak to our team for more information on equivalent products that can meet your requirements and specification.
We’re excited to announce that we are changing our online name to UK Lintels. From today you’ll notice our new domain, logo and some changes throughout our website and online presence.
For over 30 years, we’ve been Catnic lintel and steel lintel distributors. Over this time we have developed considerable infrastructure to distribute lintels across the whole of the UK via our delivery partners and our own fleet vehicles.
Why are we changing to UK Lintels?
As the UK’s largest single site stockists for lintels and our expertise in the sector, we felt that the name change was appropriate and demonstrates our focus and expertise in the space.
UK Lintels Managing Director, Grant Morris said, “Given the huge stock holding we offer our customers along with the expertise and focus we have in this space, it felt like the right time and a natural fit. We’re excited about the change and look forward to serving our customers with excellent service under the new brand for years to come.”
What is changing?
In short – just the name. Everything you know about our service is staying the same. The level of service, delivery options, bespoke cut lengths and online ordering system all stay the same.
Whether it’s a next day order to London or an overnight to Aberdeen – you can continue to rely on UK Lintels to deliver on-time and to your specification.
A note for our customers
While UK Lintels will become our new online trading name, the website remains operated by A.L. Lintels (Batavon) Limited, so you will continue to see this company name referenced on invoices, card statements and documentation issued by us. For any customer queries relating to this change and transition, please contact firstname.lastname@example.org
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