Lintel Repair

What Causes Lintel Failure?

10 March 2021

Throughout every property in the UK you are going to find lintels are a heavily relied upon support structure and are a key part to a building’s structural strength.

So, it stands to reason that a lintel should be under constant observation for any kind of fault, issues or potential damage to keep them in top condition throughout the year. The thing about lintels though is that it can be hard to tell when they are under stress or in imminent danger. So, this article is designed to help you understand a little more about when a lintel is in danger, and what you can do to stop it.

What Is a Lintel?

Some reading this article might be a little confused as to exactly what a lintel is, and what purpose it holds within a home. So, first off is a quick introduction to lintels and what they do in any building.

Above any doorway or window in a property will be a beam, set across the top of the opening and resting on the brickwork either side. These lintels can be made of natural; or man-made materials but be aware that they are often composed of timber, which can present different problems to say a stone, concrete or steel lintel.

These lintels are designed to help offset the full load weight of the wall above and surrounding these openings, so that the doorway or window underneath isn’t bearing the brunt of the full weight. If this was the case, you might find windowsills become broken and damaged, and doorways becoming warped and unusable.

So, now you know what a lintel is, but what kind of problems can you face if you are the owner of a property that has a damaged lintel? And more importantly, how can you recognise and stop lintels from getting damaged?

What Causes Concrete Lintel Failure

Concrete lintels are fairly common in today’s world. Thanks to its application as a versatile and easy-to-use material, not to mention cheap, it’s going to be found in quite a lot of buildings around the country.

Typically, concrete lintels are made with another type of building material set in the centre so that the lintel can withstand high-pressure loads more comfortably. You will usually find that this takes the form of steel bars or mesh, which work well in reinforcing the concrete lintel itself.

Now, despite the fact that concrete lintels are made to comply with the British standard when it comes to their use within buildings, these concrete lintels are sometimes subject to failure.

This can happen when the lintel itself is made poorly, placed or installed wrongly, or not used correctly in a building. Typically, a concrete lintel will develop a fault because of these circumstances, but it wont exclusively be because of them. In fact, the main cause of a concrete lintel failure is much easier to understand, track and stop: damp.

If water or moisture manages to successfully make its way inside the concrete lintel, then it can easily reach the steel reinforcement that sits inside the lintel itself. If moisture were to corrode this steel, then it will expand, which can cause the concrete that it was supporting to warp, crack, and spall, which will ultimately lead to the lintel’s failure.

This is a simpler cause of lintel failure to spot. Look out for the signs of penetrating damp within the lintel itself, as well as for signs of damp in the wall surrounding the lintel itself. You can familiarise yourself with the signs of damp here, or you could always call one of our expert surveyors to check your property (including your lintels) for signs of damp.

What Causes Steel Lintel Failure?

Steel lintels, whilst less commonplace than concrete, are similar in the manner that they are both manmade materials being used as lintels and have been used since steel began to be manufactured en masse in the UK.

Typically, you will find steel lintels being used on larger and commercial properties thanks to its tensile strength being massive in relation to its cost, and the long sections of buildings that can be covered by a singular steel lintel.

This use across longer distances makes steel an attractive lintel material in modern construction projects, and thanks to the fact that they can be coated in both waterproof and fireproof solutions, the steel itself are well protected against elements that might be a bigger problem for other construction materials.

Whilst it’s unlikely that it might occur within a residential property, steel is most vulnerable to failure when it is within a moisture-rich environment. When used in marinas, in water, or even in generally humid or wet areas, steel is much more likely to corrode and lose its tensile strength, which can be a leading cause of lintel failure.

As mentioned, steel is often coated in a waterproof solution, making it reliable for many years after installation – but if you feel that moisture could be the root cause of a steel lintel failure in your property thanks to the environment you are in, then it is worth pursuing a fix immediately.

What Causes Timber Lintel Failure?

Timber is one of the most widely used construction materials when it comes to lintels, and has been for as long as humans have been building their own houses. It’s malleable, it’s cheap, it looks great and more importantly, it has a better rating when it comes to heat preservation than its man-made counterparts and stone do.

These are a lot of positives, but what is important to understand is that despite timbers many strengths as a lintel, it is also subject to a serious weakness in several forms.

Woodworm

The first would be from household pests like woodworm. Woodworm are wood-boring insects that can easily infest and compromise the integrity of a timber lintel thank to their life cycle being dependant on the consumption of timber beams.

Typically, an egg is laid within a fault, hole, or fracture within the timber which, following pupation, hatches an adult beetle which then eats its way out of the timber itself so that they can start the process all over again. The result is a timber that looks riddled with tiny, circular holes which if left untreated can have serious ramifications on the ability of that timber to hold up under any kind of load.

You will easily be able to see when woodworm are present within timber that you use – and should you suspect they are within your property, then do not hesitate to call us so that their destructive cycle can be put to a halt as soon as possible.

Then you have the dangers of both wet and dry rot. Both of these conditions start in largely the same way, with water or moisture making its way within the timber itself, usually manifesting via damp – be it rising, penetrating or stemming from condensation.

Dry Rot

Dry rot occurs when dry rot spores (that are omnipresent)  land on the timber itself, finding the moisture-rich environment within the timber. This fungus is then capable of growing into a larger mass known as mycelium, which is capable of then producing new spores which can travel throughout your property, potentially causing more dry rot to spread throughout your home.

Naturally, this process will destroy the integrity of the timber itself and be a constant problem until it is treated. Luckily, our surveyors are entirely capable of not only identifying the dry rot itself, but also treating it and stopping it in its tracks before it causes serious structural damage not only to your lintel, but to the property.

Wet Rot

Then there is wet rot. In the simplest terms, it’s caused by excess moisture entering the timber and providing the ideal breeding ground for certain fungi that sustain themselves by breaking down and feeding on the wood cells in the timber, and in turn weakening the actual timber itself.

You might think that this sounds like dry rot, and the initial cause is indeed the same – however, wet rot (unlike dry rot) does not germinate and spread. Instead, it will be contained to the timber or wood that it has initially landed on, but this makes it no less a threat.

Again, if you suspect or notice wet rot taking hold in your lintel, then you need to contact our specialists immediately for the sake not only of your lintel, but of your property. You visit our timber repairs page you would like more information about techniques for repairing timber.

What Causes Stone Lintel Failure

Stone is another material that lintels have been constructed out of for centuries, and they (like timber) have several positives to them. They are cheap, structurally strong and easy to work into a variety of designs, not to mention good looking if done well.

The cause of lintel failure with stone though, isn’t as easy to control and monitor as it is with other building materials. True, the root cause (as with many other lintels) is moisture, but the process is a little different. Dependant on the type of stone, you could see chemical damage occurring within the lintel itself.

Limestone for example will corrode due to the acidic level present within rain. Weathering will have an effect on all types of rock – the unpredictable nature of the cracks and channels created in the installation of a stone lintel for example are the perfect place for moisture to collect, freeze and expand the lintel out, a form of physical weathering that will be hard to control.

Outside of these elements though, a stone lintel is a very reliable choice as a building material.

What Are the Other Causes of Lintel Failure?

It’s not always the intel itself that is the root cause of lintel failure. Sometimes, a property will experience lintel failure due to other factors even when the lintel itself is structurally sound.

One such cause is a change in a property’s windows or doors. PVC windows being installed in older properties is a good example of this, with older buildings (pre-1930) being designed to have the lintel take only a share of the weight around an opening, with a door frame or window frame providing the rest of the support.

PVC, being a lighter and less strong material than timber, is often incapable of sharing the load with the lintel as the building was originally designed. This can lead to more stress being put on the lintel itself, and in turn cracks or failure on the lintel.

You may also see structural movement in your property contributing towards lintel failure. Heave, listing or even foundation failure can a lintel failing. How? If the lintel were to drop out of alignment thanks to structural movement, then more pressure is going to be put on the side of the lintel that hasn’t dropped. The elevated side of the lintel will be subject to additional pressure and will lead to cracking, damage, and failure as a result.

Finally, you have the biggest cause of lintel failure: damp. Damp is the chief cause of lintel failure within all of the most common building materials used to make a lintel, and moisture will always have a large part to play in the routine degradation of a lintels ability to perform, culminating in total failure.

Getting In Touch With Our Team


Whilst damp is a big problem for lintels, it can have a wider and nastier effect on a property if left untreated. Luckily, our team our ready to help, with our damp experts on hand to advise and implement damp prevention measures, as well as lintel specialists who will be able to survey and carry out lintel repair on your property should you need it. Just call 0800 288 8660 today to learn more about how we can help your property.

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