New construction starts hint at demand for foundation piling
Foundation piling is an area of growing demand as activity picks up in the construction industry.
Newly published figures from Communities and Local Government show an increase in house-building activity, both in the private sector and by housing associations.
In the last three months of 2011, 1% more housing association construction projects began than in the previous quarter.
However, private construction saw a markedly higher increase in activity, at 6% when seasonal effects were taken into account.
Foundation piling is, of course, one of the first stages to take place on a new construction project, and suppliers are working hard to make sure we meet the growing demand as the number of new starts increase.
The official figures show that, with more than 25,000 house-building starts in the last quarter of 2011, we are now 74% higher than the industry’s lowest ebb in March 2009.
As activity continues to pick up, we will be here to help with the foundation piling that literally gives the sector the firm base it needs on which to build future success.
Foundation piling key for green communities
Foundation piling has a role to play in the future of sustainable and weather-resilient communities.
The Town and Country Planning Association has warned that, at present, many parts of England are not well prepared for future flood risks, despite investment in preventing flooding in some communities.
“While the funding for improving flood defences is imperative, we must also recognise the importance of planning and local authority cooperation in tackling challenges which operate above the local level,” says TCPA chief executive Kate Henderson.
In a TCPA guidance document, the potential role that foundation piling can play in preparing developed areas for weather events is spelled out.
The document recommends ensuring that foundation piling is deep enough during construction, so that any waterlogged soil in future does not reach the bottom of the structure’s supports.
Concrete piles’ ability to withstand variations in heat is also pointed out – making them preferable to ‘green’ alternatives such as timber-framed structures, which cannot cope as well with temperature changes.
For existing buildings, meanwhile, the document suggests underpinning foundations, so that they extend into more stable, deeper soils than was initially intended.
Underpinning foundations can help prevent heaving
Underpinning foundations can help deal with all kinds of soil conditions – and as the cold of winter gives way to the rainy days of spring, ‘heaving’ is one issue that you might encounter.
Soil is subject to a lot of weather-related effects, and we recently told you about expansive soils, which can become unpredictable in particularly dry conditions.
However, when it is especially wet, all types of soil can experience heaving – this is when the level of moisture in the ground becomes high enough that the soil expands significantly, and can literally push foundations upwards out of the earth.
By underpinning foundations, you can tackle this effect by strengthening the position of your structure within the topmost layers of soil.
Alternatively, if you are working on a new construction project, concrete piles can give support to your foundation or basement levels from deeper underground.
When weather conditions are less than favourable, there is the option of using pre-cast concrete piles delivered from off-site.
These offer the strength of reinforced concrete, but are not subject to the vagaries of the weather during their drying time, ensuring that the necessary chemical reactions can take place to make them strong and reliable.
CFA piles keep compact sites vibration-free
CFA piles are a good option on sites where existing structures are located close to the area where piling is taking place.
With many construction projects based on plots of land whose neighbouring units have already been developed, a non-invasive method of laying new foundations is increasingly important.
CFA piles – or Continuous Flight Auger piles, to use their full name – help to overcome this issue by cutting down on the vibration caused by downward drilling.
They are installed by drilling into the ground with a hollow auger, until the desired depth is reached.
Piling medium is then pumped into this hollow vertical pipe, while the auger is withdrawn – reinforcing cages can be inserted into the still-wet concrete once the auger itself is clear of the pile.
The process can be achieved with more compact piling rigs than some other methods, and causes relatively little disruption to the surrounding ground – this is good not only for nearby foundations, but also for underground infrastructure such as gas and water pipes.
If your project needs concrete piles, but you are short on room to manoeuvre, CFA piles could be the ideal option, as well as helping to ensure you stay within acceptable vibration limits if working on a site with occupied neighbouring premises.
Concrete piles are cancer-free
Concrete piles are still a strong support for any structure, despite recent reports to the contrary.
The Hammersmith Flyover was closed in late December 2011, due to structural concerns, leading to reports of ‘concrete cancer’ in its supports.
But the Mineral Products Association has pointed out that the problem was not in the concrete itself, but in the internal steel cables of the flyover.
These had corroded due to saltwater – which, in turn, had been created through gritting the road, instead of heating it from beneath as originally intended.
“It is regrettable that concrete, which is such an essential material for both existing and future infrastructure, has been misrepresented in such tabloid terms,” says MPA chief executive Nigel Jackson.
The story highlights the importance of understanding the materials used, in order to keep them in good condition for the long term.
However, it is also important to recognise that the problem was not as reported by some parts of the press – and concrete piles are still a strong and reliable option.
With pre-cast concrete piles available to bring in from off-site, construction projects can continue at a good pace, while ensuring the most important parts of the finished structure are made to a high standard by specialists.
Underpinning foundations can tackle expansive soils
Underpinning foundations is a good way to create stability in soils that are not stable enough to support structures on their own.
Expansive soils are a particular cause for concern – these are where changes in moisture content can make the ground expand or contract by quite a large amount.
Following a fairly dry 2011, soils in many areas are likely to be much drier than they would ordinarily be, making some construction projects unpredictable.
In England, for example, Met Office estimates for the whole of 2011 are that rainfall was just 84% of its normal level.
Even in December, England’s rainfall was down, at 99% of its expected average for the month.
With this in mind, builders could find dry soils are unable to support foundations as well as they ordinarily would do – and some already-completed buildings may well develop foundation problems, too.
By underpinning foundations to help improve their stability, construction projects can be kept on track, and completed structures safeguarded.
With the Met Office forecasting a warmer-than-average year for 2012 as well, the need to underpin foundations could arise more often in the future, as soils dry out and offer less support than they have done in years gone by.
Sheet piling keeps construction sure-footed
Sheet piling has many applications, from hiding a construction site against prying eyes, to keeping trespassers out and controlling access points.
But another use for sheet piling is to protect the site against the elements, as interlocking piling can create a temporary or permanent wall around the edge.
With wet weather likely in the weeks and months leading up to the summer, keeping water off of the site can be a good first step towards maintaining safe underfoot conditions.
HSE guidance warns that, if surfaces below foot are allowed to become muddy, they may need covering or treating with stone to avoid slips and falls.
Sheet piling is a good first step towards preventing this from happening – and even if the ground does become muddy, you should be able to avoid the worst of any minor floods that take place when the spring rains arrive.
Choose your sheet piling based on how long it needs to remain in place.
Temporary sheet piling is perfect for building sites that need privacy against passers-by, but where the wall created is not a lasting part of the plans.
Permanent sheet piling, meanwhile, can quickly create a retaining wall during construction, which can then be left afterwards for architectural or safety reasons.
Mini piling helps in compact redevelopments
Mini piling can help in construction work on previously developed sites, which may be surrounded by other developments that make access an issue.
With compact mini piling rigs, tighter access routes can be made viable, while less room is needed on the site itself.
Suburban environments are one example of where properties can be constructed at relatively high densities, putting room at a premium for any future projects.
However, according to a report from Policy Exchange, almost one million people moved away from urban residential areas in the years from 2001 to 2008.
“There are more jobs and higher wages in cities and nearly two thirds of people would prefer to live in the suburbs of urban areas,” the report notes.
As more people move to the edges of cities, this in turn applies renewed pressure to the availability of suburban housing – particularly when developing greenfield sites is not an option due to planning constraints.
With mini piling, even compact plots can be developed to their fullest potential, minimising negative environmental impacts and delivering the maximum benefit to housing availability in the area.
Mini pile foundations perfect for green building
Mini pile foundations are the ideal option for construction where green and sustainable building standards must be met.
Analyst IBISWorld predicts that “revenue will soar” among the leading sustainable building specialists in the coming five years.
Regions with a higher concentration of residential properties are particularly expected to lead this resurgence in activity.
According to IBISWorld, a higher local population typically drives business activity higher, which in turn leads to demand for commercial and industrial properties in the area.
The forecast is based on performance in the US market, but might be expected to be repeated in the UK and elsewhere as growth returns to construction-related disciplines.
For companies keen to ride the green wave, mini pile foundations are one ideal option.
Mini pile foundations can be put in place with compact rigs, making them perfect for smaller projects such as those that might be available in an otherwise constrained market.
Their compact nature also makes them environmentally preferable, enhancing the sustainability of the structure from the moment its first foundations are put in place.
Foundation piling in cold weather
Foundation piling presents its own obstacles during the colder months, as the interaction between the foundations and the ground around them can change significantly – particularly during extended periods of sub-zero temperatures.
If using concrete piles, for instance, pre-cast piles delivered from off-site can help to avoid the issue of the water freezing in freshly poured concrete before it has chance to harden.
Meanwhile, foundation piling in permafrost ground allows the temperature itself to become a beneficial factor – the shear forces between the foundation piles and the frozen ground add to the strength of the structure.
It is therefore important to know from the outset what kind of foundation piling you need for a particular project – and how the changing weather conditions year-round might affect their strength.
We can supply pre-cast concrete piles or pour fresh concrete on-site, with underpinning an option where poor ground conditions complicate the installation of your foundations.
Similarly, we offer soil nailing to stabilise slopes and banks, which can help to ensure ground frozen in winter does not become unstable as the warmer weather arrives in the new year.