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!
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.