Post-Demolition Site Surveys

The demolition trade has a certain character for being a tough atmosphere in which brute force takes priority over calculated thinking; however this image is far from correct. There is a substantial amount of work that happens behind the scenes of the demolition and construction industry that is firmly grounded in the academic arena.

One part of this unnoticed work is site surveying, or more precisely pre-demolition and post-demolition topographical surveying. This sort of work demands a good balance of specific technical knowledge as well as experience of the industry and a natural intuition for the complexities of the job.

Topographical Surveys

A topographical survey is a report of the actual features of a given plot of land. The purpose of a topographical survey is to chart the naturally occurring and man-made traits of a particular landscape to a high degree of precision. Whilst topography itself can refer to the surface of virtually any object, it is more commonly associated with the surface of the Earth.

Topographical surveys can be carried out on a very wide range of environments, from open countryside to urban areas and across a variety of elevations and land surfaces. Surveys can be designed to take into account a great many factors, such as ground variables or vegetation, and as such can be used for a multitude of tasks.

Common Applications for Topographical Surveys

Probably the most extensively used, and most generally recognised application for topographical surveys is cartography, or map making. Modern maps include a great deal of information about the terrain they relate to, including waterways, elevations and ground surface, all of which will have been obtained via a topographical survey. This information is also being provided online.

Topographical surveys also have a key role to play in the construction business. When people or organisations are looking to build any kind of structure they will need to perform extensive surveys as part of the design stage of the project. These surveys are often an important part of any application for planning permission too.

Surveys definitely play a key safety role in primary industries such as mining, or in other industries that interact with the terrain, such as demolition and infrastructure. Organisations in these fields will use surveys to prepare their projects, but also to make sure that they can guarantee the safety of their staff on site.

Under modern regulatory control, the specialists that perform demolition surveys must always be well qualified to guarantee the trustworthiness of the survey results.

Types of Survey

The world of topography covers a large number of physical features so it is beneficial to identify what form of topographical survey is suitable for a particular situation. A few of the more typical types of survey required for construction sites are reviewed below.

“Lie of the land” Surveys

These types of topographical surveys are fashioned to create a summary of the physical properties of any given plot of land. Although the information gathered by the survey will be very accurate, and might be very extensive, the purpose of these surveys is to give a site summary.

These surveys will generally incorporate a boundary survey that sets out to define the extent of the site and spotlight any particular restraints that are determined by the geography of the site. They can also include a level survey that will plot the elevation of the terrain and the various gradients that exist. A survey can be customised to specification though.

Building Surveys

Building surveys are more typically concerned with man-made structures on a site, including the surveying of special equipment and even infrastructure features. This type of survey is more commonly associated with the demolition sector since it can give a detailed plan of the building to be demolished.

A building survey will probably include a measured survey, which entails creating a comprehensive plan of the external and internal proportions of a building. Depending on the requirements of the project, a measured survey might provide simple building “footprint” measurements, or might produce a highly detailed plan of the structure.

Content of a Topographical Site Survey

A survey of a demolition site will almost always include the information gathered by the types of boundary and building surveys mentioned above. This information will be required so the demolition company can plan a demolition that is both adequate and safe.

Surveys will often contain information about the utility services that are present on a site prior to any demolition or construction work takes place. This is an essential safety aspect because any unmonitored destruction to pipes and cables carrying water, gas and electricity might be very dangerous.

Another aspect of the site survey will often be an inventory of resources on the site. This type of study will be a quantity survey of the various kinds of materials that can be found on site, for example, tiles and masonry, concrete that can be utilised as hardcore or even wood. By getting an accurate audit of site materials the construction firm can more precisely determine the need to import building resources, or they can re-use the materials on a different project.

Topographical surveys and material quantity reviews form one faction of demolition services provided by modern companies that conform with industry best practices.

Importance of Site Surveys

Perhaps the most significant reason to undertake a topographical site survey is to ensure the health and safety of the individuals who will be working on the site. The industrial sectors that most frequently call for site surveys are risky enough as it is without having to be concerned about the integrity of the ground on which they are working.

Another important reason to get a proper survey done is to highlight any potential difficulties that may arise because of the physical characteristics of the area. Particular things may not be evident on the surface of the site and will only be discovered once digging or demolition has begun. By then it may be too late to fix these problems, or at best they will be costly issues to solve.

The inventory of site supplies, as previously stated, can be of great benefit to a demolition or construction organisation working on a project. Not only are construction materials themselves costly, but importing them to the site may be a very expensive task in itself. Any time that material can be recycled on site offers an opportunity to save development time and funds.

Topographical surveys can also highlight other areas that will be of use to the project planners. For example, if the gradients on a site would be prohibitive to specific vehicles or equipment then a new access route or alternative equipment will need to be found.

Positioning of Survey Control

During the surveying and construction stages of a building project, the equipment required for the physical surveying of the site and control of the survey data will often be kept on-site. This is obviously a problem when it comes to the demolition phase of a project since the machinery is both expensive and sensitive. It is therefore wise to move this equipment off-site during demolition.

Once the demolition has occurred and the site has been deemed safe for workers to return to it, the surveying equipment can be restored to its original position on site. This will allow for effective data gathering to take place for a post-demolition study, and keeps a single point of contact for anyone who requires the topographical survey information. Most surveying firms will oversee this redeployment.

Many towns and urban centers up and down the country require home demolition earlier than building of modern housing estates can commence.

Who can Perform Site Surveys?

Because topographical site surveys can play such a critical role in the success or failure of a building or demolition project it is vital that they are carried out thoroughly by the right people. There are different branches of site surveying and each one will have specific certificates associated with it. Getting surveyors with these specific skills will certainly be beneficial.

When selecting a company to undertake the surveying work necessary for your project it will be sensible to choose a business with a good reputation and a proven track record. Ask to see reviews of their previous work and try to obtain feedback about their performance on past projects. It may also be worth thinking about how a company can deliver their survey data, i.e. in 3-D models or CAD ready formats, for ease of integration with other members of the project team.

Who will use the Survey Information?

When an adequate level of details has been accumulated by a site survey it must be passed out to the appropriate personnel on-site. Who gets what pieces of information will mostly depend on the job roles being executed, but can also rely on the stage that a project is at.

Project Planners

Project planners will generally need access to all of the information gathered by a topographical survey, although they will particularly need to use information about the physical relief of a site before the design phase, and a site materials inventory before they can plan the construction phase.

Demolition Experts

Demolition organisations will want to know about the internal and exterior characteristics of any building or structures that they are set to take down. Whilst every job will have different requirements, demolition workers will typically need to know about the fundamental structure of a building and the materials it is made out of. They will need this information before demolition can take place.

Site Engineers

Construction engineers on-site will be particularly interested in the survey statistics about the relief and topography of the site. It is normally the case that they will want to assemble on a flat surface, so they will use details about the natural lay of the land to calculate what work will be required to create a stable foundation for any structure. They will want this information before and in the course of the construction stage of a project.

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