U&M Group


Underpinning a House

Has anyone ever suggested that your house might need to be underpinned? The suggestion strikes fear in many people. Part of that is because it can be an expensive process, but there are also many misunderstandings about underpinning and what it means for a building.

What Is Underpinning?

Though the word underpinning is more often used in a figurative sense, it actually means adding to the foundations of a building in order to strengthen them. This may be because the original foundations are inadequate, which was quite common in older buildings.

Most commonly, however, the reason for underpinning a house is that it’s suffered subsidence. This may be because the ground beneath the building is weak or has become waterlogged. Alternatively, there may be excavations, such as old mine-workings, underneath.

Not all cases of subsidence require underpinning. For instance, the ground may have become waterlogged because of a fault in the drains, and fixing the drains could be enough. However, if the situation is permanent, there might be no alternative to strengthening the foundations.

How Is Underpinning Carried Out?

Broadly, there are two methods of underpinning a building — traditional underpinning and piling.

The traditional method, also known as mass concrete underpinning, involves excavating beneath the foundations, section by section, and filling the cavities with concrete. This is a longwinded process that’s far less common than it used to be, but it’s still an option where alternatives are unsuitable.

Piling, on the other hand, has grown in popularity, especially since the introduction of minipiling, which makes the process easier in a confined space. Essentially, piling involves either driving or boring below the foundations and inserting piles that rest on either stronger earth or the bedrock. This transfers the weight of the building down to a solid support.

What’s the Cost of Underpinning?

Most immediate, underpinning is an expensive process. Typically, underpinning an average-sized house is likely to cost between £10,000 and £15,000, although it may be more if the subsidence has made structural repairs necessary. However, it’s quite possible your building insurance policy will cover this, so you won’t have to pay out that amount.

A more long-term cost is that an underpinned house is often more difficult and more expensive to insure. This is because of insurers’ often baseless assumption that the problem is likely to recur. However, some insurers specialise in underpinned buildings or have dedicated underpinning teams. As long as you can provide evidence that your house is now secure, it should be possible to arrange insurance.

The more relevant question, though, is what it’s likely to cost you not to have underpinning done — and that could be losing your home. You can find out more about underpinning a house by getting in touch with us for a chat.


Here’s an article you might find interesting: Does It Affect Your Insurance if Your House Is Underpinned?

Piling is a way of securing the foundations of a building that rests on weak soil or other material, such as sand or silt.

What Is Piling and What Can It Do for Your Home?

If you hear about piles in the context of construction, you may think about major structures, such as bridges. While piling is certainly crucial in such projects, it can also be used for your home.

What Is Piling?

Piling is a way of securing the foundations of a building that rests on weak soil or other material, such as sand or silt. Building on this kind of material risks the structure shifting or collapsing due to subsidence, which makes piling especially valuable for a construction whose foundations are in the bed of the sea or a river.

The idea is that piles of concrete or grout are either driven or bored down through the weak soil down to a stronger level, sometimes the bedrock. This enables the weight of the building to be transferred down, by way of the piles, to a depth where it can be supported. Piles can be inserted in one of two ways:

  • Bored/drilled — This is where a hole is drilled down to the stronger level. The drilled flight supports the sides of the bore while the concrete or grout is poured in and can be removed once the pile is solid.
  • Driven — This is where the pile is driven directly into the ground, removing the need to support the hole while the pile is being formed.

What Can Piling Do for Your Home?

If your home has suffered subsidence, whether from saturated soil, excavations beneath it or any other cause, the foundations may need to be strengthened to prevent the building collapsing. This is known as underpinning, and the traditional method involves laboriously excavating the foundations section by section and laying extra concrete.

Increasingly, however, piling is taking the place of mass concrete underpinning. It has the advantage of being quicker and less disruptive, since there’s no need to dig under the house. Combined with relatively small and compact machinery that can work in confined spaces, piling can be the ideal solution.

Which Type of Piling Suits Your Home Best?

This depends entirely on the nature of the ground and the conditions in which the job needs to be done. In general, boring has the advantage of creating less vibration, but it isn’t usually suitable if the ground is too saturated. Driving, on the other hand, works for any kind of soil, and the machinery is fairly small and convenient to fit inside.

The best way to determine the ideal type of piling for your needs is to consult a specialist piling company. You can get in touch with us if you want to discuss what you require.

Read more on piling services or learn about piling techniques.


A house that needs structural repair

Structural Repair and Strengthening

Buildings aren’t invulnerable, and a wide variety of factors can lead to structural damage. Whether your home has suffered from subsidence, has experienced traumatic damage or (if it’s an older building) is simply feeling its age, it may need to be repaired or strengthened.

So what might be needed to achieve this?

Masonry Repairs

Whether your home’s walls are made of brick, stone or concrete, the materials are likely to degrade over time, even if there’s been no specific damage.

With a brick building, for instance, the bricks may have crumbled or the mortar holding them together may have degraded. This means the bricks will need to be replaced, or refaced if the damage is only superficial, or that the brickwork has to be repointed.

In the case of a stone building, the stones may need to be repaired or refaced. Concrete may also need to be repaired, or perhaps it’s enough to recoat it.

Wall Tie Replacement

Walls are held up by more than just masonry and mortar. Crucial components of cavity walls are the wall ties that are hidden from view but hold the walls together.

Wall ties are traditionally made of metal, though now they can be made of synthetic materials. They generally last well but can eventually become corroded. They can also sometimes break, which will often be shown by horizontal cracking or bowing. In either case, they need to be replaced in order to stabilise the wall.

In addition to replacing wall ties, walls can be damaged, resulting in delamination of the masonry. To prevent further deterioration, extra ties need to be put into the wall.

Masonry Reinforcement

If masonry has been damaged by subsidence or other ground movement, it’s going to need more than just repair. You may need to have the building’s foundations underpinned, but there could be other options, as long as the structural survey considers them appropriate.

One option is to combine joint reinforcement to form ties and deep masonry beams to distribute the structural load more evenly. The process is completed with lateral and vertical restraints.

Listed Buildings

If your home is a listed building or in a conservation area, you won’t have as free a hand as normal to make repairs. For instance, you’ll need to ensure you match the type and colour of the original bricks or stones, and you may even need to use a type of mortar not common today.

In this case, it’s vital that your contractor understands these requirements and is equipped to meet them, as well as all your other needs. If you have concerns that your home may need structural repair or strengthening, you’re very welcome to get in touch with us.

COVID-19 News Update

COVID19 Pandemic

At the time of writing, The U&M Group is largely closed, following guidelines issued by the UK Government and Public Health England to help play our part in minimising the potential spread of the virus.

Our offices are operating with a skeleton staff and reduced hours.

Key staff in all departments have laptops and mobile devices and are home working.

Whilst our site activity has largely ceased, we have retained a limited number of operatives to undertake any emergency call out work, temporary propping, security etc that may be required during this partial lockdown. Please contact us through info@underpin.com.

As the advice is in a constant state of flux, we will be actively monitoring the situation and will implement any updated advice or guidelines.

We would also wish you all well during these very sad and disruptive times.

Kind regards and stay safe


David Gakhar

How Will I Know Which Type of Brick, Stone or Concrete is Required?

Whether you’re having major rebuilding done on your property, adding an extension or commissioning a new build, it’s vital to identify the appropriate materials to use. Where the main structure of the building is concerned, this is likely to be either brick, stone or concrete — but there are many types of all three. How do you know which is required?

Which Type of Brick Is Required?

Bricks are the most common material used for houses throughout the country. They have the advantage of being relatively cheap and versatile, and they can be used to create cavity walls for better insulation. On the other hand, the larger (and particularly higher) the building, the less efficient bricks will be.

Bricks are normally made of clay, but other materials can have certain advantages. For instance, sand lime bricks will give a smoother finish, while concrete bricks are perfect for above and below damp-proof courses. Mass-produced extruded bricks can be produced quickly and cheaply, whereas soft mudbricks can be more aesthetically pleasing but are more expensive.

One of the great advantages of bricks is that they can be made in any shape required. Specialist bricks are available for returns, capping, channels and curved structures, as well as many other uses. The bricks you require will depend largely on their place in the structure.

Which Type of Stone Is Required?

Stone was once the building material of choice for high-status buildings, from the marble temples of antiquity to mediaeval castles and cathedrals. It’s also found in traditional houses in areas where an appropriate stone is found, such as the Cotswolds or the Lake District, and new builds in these areas may use the same materials.

Only a few of the thousands of types of stone found in the UK are suitable for the primary material of a building, including granite, sandstone and limestone. Marble can be used, but is likely to be too expensive to be practical.

However, these and other stones, such as quartzite, basalt and travertine, are often used for floor tiles, cladding and various interior features. Slate is also excellent for floor tiles, but its most familiar use is as a roofing material.

Which Type of Concrete Is Required?

Concrete is a man-made material, created by mixing cement, water and aggregate. Although used by the ancient Romans (for the Colosseum, for example), the secret was lost until modern times. Today, however, concrete is used for everything from garden paths to skyscrapers.

At least a dozen types of concrete are available, but the most common are:

  • Plain concrete — used for paving or for smaller buildings that don’t require high tensile strength.
  • Lightweight concrete — most often used for floors, window panels and roofs.
  • Reinforced concrete — has steel embedded in it during manufacture, giving an extremely strong material that’s used extensively for major buildings.
  • Precast concrete — moulded in advance for use in a wide variety of structural components.

While this may give you an idea of which materials you may need, the best advice would be to consult an expert building firm, who’ll be able to give you suggestions for your specific project. You’re very welcome to get in touch with us for advice.

Construction Surveys — How Are They Done?


Whenever you’ve bought a house, the chances are you’ll have had a survey done to ensure you’re not buying a property that will give you problems further down the line. This is the most common reason for having a survey done, but not the only one.

What Is a Construction Survey?

A survey is simply a professional examination of a building, usually by either a Chartered Surveyor or a Structural Engineer, to determine whether its construction is sound. Though not obligatory, it’s common sense to have one done before buying a property. This is usually a fairly straightforward affair unless the building is older or shows signs of dilapidation.

In this case, or if your home shows signs of subsidence or structural damage, a more detailed structural survey might be required. This is normally done by a Structural Engineer, who’ll carry out a full internal and external survey to discover any defects that might not be obvious.

What Does a Structural Survey Involve?

The Structural Engineer will examine the exterior of the building for damage. This will include the roof, along with the chimneys and gutters, as well as the walls, doors and windows for cracks or frames pulling away from the masonry. They’ll also check that your drainage is functioning properly — correcting this could make more substantial work unnecessary.

Additionally, they’ll look at the interior, including the roof space. This will include examining all the walls, floors and ceilings for warping or cracks, as well as woodwork for signs of rot or woodworm. They’ll be on the lookout for signs of damp or condensation, too.

Why Might You Need a Structural Survey?

The most common reason for arranging a structural survey is if you suspect your home has suffered from subsidence. The symptoms are likely to be substantial internal or external cracks in the walls or the frames of the doors and windows pulling away from the masonry.

It’s vital to have a survey done in these cases since subsidence can be caused by a variety of conditions. If the problem is weak soil or a cavity under the building (old mine workings, for instance), you’ll probably need your foundations underpinned. Sometimes, though, the subsidence can be stopped more cheaply by fixing your drains or removing tree roots.

The Structural Engineer is likely to spend between four and eight hours surveying your home, with the report delivered within ten working days. Once you have the report, you’ll be able to discuss with a construction firm what needs to be done.

You’re very welcome to get in touch with us if you want to know more about Construction Surveys.

What Are the Different Types of Brick Around?

What Are the Different Types of Brick Around?

Although modern buildings can be constructed from a wide variety of materials, brick is the traditional material of choice in most parts of the UK. There’s something reassuring about a brick-build home, with its bond left clearly visible.

But is a brick simply a brick? Not at all.

Materials for Bricks

Clay is the most common material for bricks, but this can vary according to where it comes from. The most obvious difference is the colour, indicating the type of clay, which tends to reflect the part of the country it comes from. Broadly, red bricks are characteristic of the north, for instance, while London and the Home Counties are more likely to have yellow or cream bricks.

However, a number of other materials are available for bricks:

  • Sand lime bricks, consisting of a mixture of sand, fly ash and lime, make a smoother finish possible.
  • Fly ash clay bricks are made from a mixture of fly ash, cement, sand and water.
  • Concrete bricks are ideal to go immediately above and below a damp-proof course.

Ways of Making Bricks

Bricks can be manufactured in different ways, which affect how they’re best used. The main methods are:

  • Extruded or wire-cut bricks, where the clay is extruded into a column and wire-cut into individual bricks. This is usually done by machine, keeping costs down, and produces smooth bricks.
  • Soft mud bricks, where the clay is dropped into individual moulds, producing creased faces. This can be done either by machine or by hand, though of course handmade bricks tend to be more expensive.

Alternatively, you can reuse bricks from demolished properties, which will reduce the carbon footprint of your project.

Shapes of Brick

The most common shape is the facing brick, which is the one normally found in the brickwork of a straight wall. However, bricks need to be used for the angles and corners on a building, too, and specialist bricks are available to suit all of these.

For example, angle and cant bricks are used to create returns and chamfers, while coping or capping bricks cap freestanding walls. There are also channel bricks, used to form channels and gutters, and curved sector bricks can be used for chimneys, pillars or columns.

Hollow bricks, around a third the weight of normal ones, are suitable for partitions, while the perforations in airbricks help with the circulation of air. There are many other specialist bricks available, and they can be custom made for specific uses. You’re very welcome to get in touch with us to find out more about what’s available.


So What Actually Is Underpinning?

Terms like underpinning are thrown about in the construction industry, but it’s not always easy to be clear what they really mean. So what exactly is underpinning, and what implications does it have if you need to have your home underpinned?

What Is Underpinning?

Underpinning simply means strengthening the foundations of an existing building. This is usually because there’s subsidence underneath, caused by weak or saturated soil or cavities such as old mine-workings. Some causes of subsidence, like tree roots interfering with the foundations, can be dealt with simply, but often underpinning will be required.

There are two main types of underpinning:

  • Mass concrete underpinning is the older method, which involves excavating beneath the foundations, section by section, and filling with concrete. This is a longwinded and fairly disruptive method, but there are cases where it still offers the best option.
  • Minipiling is a newer technique, in which piles are driven or bored through the weaker soil to a level of bedrock or stronger soil, allowing them to support the weight of the building. This technique has the advantages of being relatively quick and non-disruptive.


What Does Underpinning Cost?

The cost of underpinning jobs can vary considerably, according to a number of factors. Obviously, the extent of the work required will be a major issue, but the cost may also be affected by any specific difficulties encountered. It can also depend on what part of the country you live in.

For an average house, you could expect to spend between £10,000 and £15,000, though it could be more if you also require structural repairs. While this might seem expensive, it may be covered by your building insurance. In any case, the alternative of ignoring the problem is likely to cost a good deal more in the long run.

You should always get at least three quotes, but remember that the cheapest won’t always be the best. Find out whether the company specialises in underpinning, and whether it has a track record of satisfied customers.

Will Underpinning Affect My Insurance?

One of the concerns often raised with underpinning is that it might be difficult to insure your home once it’s been underpinned. It’s true that insurance companies tend to be cautious, assuming the problems that caused the subsidence haven’t gone away.

However, there are specialist firms that will insure underpinned properties. This may cost a little more than average, but it shouldn’t be difficult to insure your home.

You’re very welcome to get in touch with us if you want to know more about underpinning.

The History of Construction

The construction industry is one of the foundations on which the modern world is built, so it’s not surprising this has always been so. The history of construction is not only as old as human civilisation, but even older.


Ancient Construction

The earliest forms of construction were merely temporary shelters made by weaving grass or stretching animal skins. As long ago as 11,000 years, though, more permanent structures were being built in a few areas, and this gradually spread through the ancient world.

A wide variety of materials were used, depending on what was easily available and what the building was used for. In Egypt and Mesopotamia, for instance, clay bricks were favoured, while timber-framed constructions were preferred elsewhere, such as China.

Besides dwelling places, most civilisations built massive monuments, and these were usually of stone. The Egyptian pyramids and the great Greek temples are examples, and the challenges of creating these often advanced knowledge of construction techniques.


Pre-Modern Construction

These trends continued through the middle ages and beyond, both in Europe and throughout the world. The technical achievements of the great European castles and cathedrals were more than matched by the great Islamic mosques with their magnificent domes and the temples of southern and eastern Asia.

At the same time, the growth of urban living (which saw Asian cities with populations of over a million) required new solutions. In Europe, the traditional wattle and daub gradually gave way to the brick buildings that are still familiar.


Modern Construction

Following key 18th century developments, such as the use of iron and glass in construction, two of the most important breakthroughs that heralded modern construction were concrete and steel frames. Concrete had been used by the Romans (for the Coliseum, for instance), but the technique had been lost.

These enabled the development of high-rise buildings, which were also aided by the introduction of cranes to make their construction possible and the invention of the lift, which made them practical to use. During the 20th century, prefabrication techniques created a revolution in fast, cheap construction.

The construction industry is still evolving. Perhaps one of the most significant directions of evolution in the 21st century is the quest to find designs and materials that are ecologically friendly. This could make the buildings of the future as different from those we’re used to as a Tudor house is from a modern skyscraper.


On the other hand, the essential principles of good construction have altered very little over thousands of years, however much the methods, tools and materials have changed. If you want to know more about great construction today, feel free to get in touch with us.

What Are the Signs of Structural Damage to a House?

As a house ages, faults are likely to appear. Some will be minor issues caused by settling, but sometimes there will be signs of genuine structural damage. These require prompt action.

Signs of Structural Damage to the Foundations

The foundations of a house are crucial to the entire structure, and when they’re damaged, the symptoms may show up all over the house. This is because damage to the foundations will result in the building’s overall structure becoming uneven and extra pressure being put on some elements.

Typically, the signs to look out for include:

  • Substantial cracks appearing in the internal walls, especially above doors or windows, or where the wall meets the ceiling.
  • Doors or windows begin sticking.
  • The frames for doors or windows are pulling away from the wall.

All these may be due to causes other than damage to the foundations, while very small cracks are probably just due to settling. However, if you’re in any doubt, it’s important to have the foundations checked.

The best way of doing this is to inspect where the foundation meets the crawlspace walls with a flashlight. Hairline cracks are no problem, but more substantial cracks may indicate that your foundations need repairs. This is especially true for vertical cracks that are wider at the top, or any large horizontal cracks.


Repairing Structural Damage to the Foundations

The first and most important step in repairing damaged foundations is to restore their stability. If the damage has been caused by an external factor, such as tree roots or damaged drainage, removing the problem may be enough.

If the problem can’t be easily removed, however, you may need to have your foundations underpinned. This can be done by excavating below them and putting in extra concrete, but in most cases a better option is mini-piling. In this case, piles are either driven or bored through the weak soil to a stronger level, where they can hold the structure secure.


Structural Repairs of Buildings

Securing the foundations is vital, but damage done still needs to be repaired. Typically, this may involve:

  • Stitching substantial cracks in walls, using helical wires.
  • Repairing and resealing door and window frames that have pulled away from the wall.
  • Repairing or replacing worn masonry.
  • Replacing worn or rotten timbers.
  • Repairs to a sagging roof.

However, the precise repairs that your house may need will depend on the damage done, and that requires professional assessment. If you think your house may need underpinning or other structural repairs, you’re very welcome to get in touch with us.

Can You Build a House Without a Foundation?

We assume that any building needs a foundation. It’s so obvious that we use it widely as a metaphor — the foundation of arguments, beliefs, organisations and so on. The foundation is what makes anything safe and secure.

So can you really build a house without a foundation?

What Is the Foundation For?

The simple answer is that of course, you can — as long as you don’t need it to stand for long. Historically, houses without foundations have tended to be simple affairs, built around an earth floor, which weren’t designed to last.

Although a building may be able to support the downward thrust of its load without a foundation, it’s the sideways motion that creates the problem. As the ground changes temperature with the seasons, it expands and contracts, causing instabilities that make the building lurch.

This means that, unless it’s built on a rock so solid that there’s no variation, stability depends on having the structure’s base resting on a level deep enough to maintain a constant temperature. This should ensure that lateral movement is kept to a minimum.

Are There Houses Without Foundations?

Substantial buildings have been successfully constructed without what might be thought adequate foundations. Perhaps the best known is Salisbury Cathedral, built on marshy ground, which supports a spire on foundations of just four feet depth. This can be achieved by building on a “raft” in soft ground, which acts in a similar way to traditional foundations, but it’s not an easy technique to get right.

Other types of buildings that can be created without foundations are those built on piles or stilts. This usually happens on flood plains or marshy coastal areas, but these homes do actually have foundations, if not traditional ones. Here, the weight is distributed down through the piles to a stable level, essentially doing the same job as a more standard foundation, with the added load capacity created by ‘skin friction’.

What If My Home Doesn’t Have Adequate Foundations?

Although you’re unlikely to have a home today without any support, some older houses were built with shallow foundations. Other houses may have had what seemed adequate foundations, but subsidence or other movement has weakened them.

In these cases, the foundations of an existing building can be extended down to a more stable level. This is known as underpinning and can be done either by excavating below the existing foundations or by sinking piles to transfer the weight to a safe level.

If you have any concerns about whether the foundations of your home are adequate to support its weight, you’re very welcome to get in touch with us.

Most Popular Basement Design Ideas for 2019

If your home has a basement, or if you’re thinking of adding a basement, you already have an advantage over most properties. What are you going to do with space, though?

Traditionally, basements have tended to be relegated to marginal uses such as storage or utility rooms, but that doesn’t have to be the limit of your imagination. Here are a few currently popular ideas for using your basement.

Home Office

There’s a revolution in working methods, with more and more people working from home, and the basement is a perfect location. Cut off from the living areas, but still only a staircase away from home comforts, it can be effectively soundproofed and fitted out with office furniture — or even a comfy chair to curl up with your laptop.

Guest Suite

If you regularly have guests coming to visit, your basement could make an ideal guest suite, especially if it features a light well to bring in the daylight. Besides a bedroom, the suite can include a bathroom, and more if there’s room, such as a lounge and a kitchenette.

Home Gym

Do you love to keep fit? But do you have the choice between constantly heading to the gym and trying to exercise in the middle of everything going on at home? Your basement could be a dedicated gym, with the equipment kept out of the way and space where nothing matters but reaching your targets.

Games Room

Even if you’re not dedicated enough for a home gym to be worthwhile, your basement offers the perfect space for games such as pool, table-tennis or air-hockey. Whether you want to play with family or friends, a games room in your basement means you can dive straight into it without having to set up the tables.

Home Cinema

Watching TV casually in the living room is fine, but for a more immersive experience for watching films, how about a dedicated home cinema space in your basement? Depending on how far you want to go, you could set the room up with rows of seating — and even have popcorn on tap.

Extra Lounge

Your basement doesn’t have to be for unique use. If there are competing claims on the main reception rooms upstairs, you could simply set it up as an extra lounge for members of the family who want a little quiet.

These are just a few of the many popular basement designs. You’re very welcome to get in touch with us for more ideas.

Which Soil Is Best Suited to a Pile Foundation?

Pile foundations are most commonly associated with strengthening a building’s existing foundations through underpinning, but this isn’t its only use. Piling is also sometimes the most suitable technique for new-build foundations. The crucial factor is frequently the type of soil below the structure.

Soil Quality and Pile Foundations

The reason soil quality often determines the need for pile foundations is that weak soil or soil that’s saturated with water may be unable to support traditional foundations. The soil is likely to give way, resulting in the foundations — and therefore the structure they’re supporting — sinking further down.

If these conditions persist to a depth of over 2m, piling can be the answer. This solves the problem by taking the weight down through the weak soil to a firmer layer of soil or rock below, allowing the weight to be distributed down to a secure basis that can support the building.

Which Soils Are Weak?

The types of soil that most often require piling are those with high clay or silt content since these are fine-grained soils. They tend to collapse more easily, or else cause more uplift when they freeze.

Sandy soils are stronger but can still cause problems, while soils with high organic content can also be too weak to support traditional foundations. This is most likely to be on land previously used for agriculture or horticulture, but it can be found elsewhere.

Clay and silt are especially vulnerable if they’re saturated since they liquefy easily. However, anywhere that has a high water table or shows signs of being marshy are potentially vulnerable, and piling should be considered.

New-Build Foundations and Underpinning

If you’re planning a new build, it’s vital to commission a thorough survey of the soil quality before deciding on how to proceed. If the survey shows the soil as very weak, it may be necessary to abandon the project altogether, but piling can be used to take advantage of stronger levels deeper below the surface.

On the other hand, an older property that’s suffered from subsidence can benefit from being underpinned by piling. The soil may not have been properly surveyed at the time of building, or conditions may have changed — a rise in the water table, for example. Quite apart from often being a more cost-effective technique than traditional underpinning, piling becomes a must if the soil is weak.

If you want to know more about which soil is best suited to a pile foundation, feel free to get in touch with us.

What Is the Work of a Piling Contractor?

Few buildings will last without solid strong foundations, and various foundation types are best suited to different situations. Increasingly in recent decades, the technique of choice has tended to be piled foundations, largely driven by innovation as well as increased costs in spoil removal and concrete (as well as the environmental considerations).

What Is Piling?

Piling is a very old construction method, but recent improvements in techniques and equipment have made it the most popular approach to foundations. It involves inserting long columns, either in situ or pre-cast, usually of steel or concrete, into the ground. These reach a strong layer of either soil or bedrock, allowing the weight of the building to be securely distributed down to this solid level.

Piling can be used for large structures, particularly when they’re built in water (wind turbines, for instance), but one of the most common uses is for strengthening existing foundations. For this process, known as underpinning, mini-piling is often used. This technique is also very suited to new house foundations or extensions where access for larger CFA rigs is an issue.

What Are the Types of Mini-Piles?

There are broadly two types of mini-piles — bored and driven. For the bored type, the machinery removes the earth and inserts sections to support the side of the hole, if required. When this is complete, steel reinforcement cages are inserted (dependent upon the design) and grout is poured or injected to form the permanent pile.

Alternatively, ready-made piles can be driven straight into the earth, displacing the soil around them. This has the advantage of compacting the soil surrounding the pile, making it stronger. The method used will depend on issues like the quality and type of ground conditions and working conditions on the surface.

What Does the Piling Contractor Do?

Before anything else can happen, it’s essential to examine and assess both the site in general and the soil in particular. Issues like the strength and type of soil, the level of the water table, headroom if the piling will take place in a confined space and access to the site will all affect the type of pile best suited and the machinery that can be used.

After detailed plans have been made, the contractor will bring in their piling experts and machinery. This is one of many reasons why using a specialist piling contractor is important since they will have these resources available, rather than having to hire them in.

The piles will then be inserted, by whichever method has been chosen as the most appropriate. For mini-piling, this will often mean restricted access piling rigs, that have remote power packs considerably reducing the amount of site space required. A professional piling contractor will clear up and make good the site when finished. If you want to know more about piling, feel free to get in touch with us.

Does It Affect Your Insurance if Your House Is Underpinned?

If you’re thinking of buying a house that’s been underpinned due to subsidence, people may suggest you’ll find insuring it difficult and expensive. You may even be advised by well-meaning friends not to have your existing house subsidised, for much the same reasons.

The second case flies in the face of reason since even if the warnings were true, the property will still be far safer after underpinning. But is it really true that an underpinned home is harder to insure?

What Is Underpinning?

Underpinning can describe various techniques of strengthening a building’s foundations. This could be done for a number of reasons — subsidence (where the structure is slipping into the weak ground) is the most common, but a building might also be underpinned to provide extra support for a substantial extension.

The two most common methods are mass concrete underpinning and piling. The mass concrete method, also known as traditional underpinning, involves trenches being dug out under the building and filled with concrete.

While this is still the best solution in some cases, it’s being largely replaced by mini-piling, where piles are drilled or driven down to a level where the ground is stronger. The piles then transfer the building’s weight down to the strong soil or bedrock.

Will Underpinning Affect My Insurance?

Insurers tend to be wary of any structure that has ever suffered from subsidence. While underpinning should be seen as a problem solved, they can still be nervous that the subsidence could return.

In the past, that has tended to mean insurance for an underpinned home has been hard to get and more expensive. However, the situation has improved in recent years.

While many mainstream insurance companies are still reluctant to touch an underpinned property, an increasing number recognise that it’s not always bad. Some companies have dedicated underpinning teams, while there are also specialist brokers.

You may need to get specified work done, such as having your drains tested to ensure they’re watertight. However, if you can demonstrate that the underpinning has done its job, you can often find insurance at a reasonable price.

A Good Job Is Essential

This depends, of course, on the insurer being satisfied that the underpinning is secure, making the further risk to the building acceptably low. Consequently, it’s essential that you’ve had an expert job done, not a fix-up by a general builder.

If you want to know more about how specialist underpinning can make your home secure and keep your insurance costs down, feel free to get in touch with us.