The demolition industry has a particular character for being a harsh atmosphere in which brute force takes precedence over calculated thinking; however this image is far from appropriate. There is a substantial amount of work that happens behind the scenes of the demolition and construction industry which is firmly grounded in the academic arena. Furthermore, this unseen work is critical to the success of the more visible procedures.
One branch of this unnoticed work is site surveying, or more precisely pre-demolition and post-demolition topographical surveying. This type of work calls for a good balance of specific technical know-how as well as experience of the industry and a genuine intuition for the intricacies of the job. This article explores the ins and outs of this work.
Topographical Surveys
A topographical survey is a report of the physical features of a given plot of land. The aim of a topographical survey is to map the naturally occurring and man-made features of a particular landscape to a high degree of precision.
Topographical surveys could be carried out on a very broad range of landscapes, from open countryside to urban areas and across a variety of elevations and land surfaces. Surveys can be developed to take into account a great number of factors, such as ground variables or vegetation, and as such can be used for a multitude of tasks. A few of the more common uses are discussed below.
Common Applications for Topographical Surveys
Probably the most widely used, and most commonly recognised application for topographical surveys is cartography, or map making. Modern day maps include a great amount of detail about the landscape they relate to, including waterways, reliefs 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 industry. When individuals or companies are looking to build any kind of structure they will need to undertake extensive surveys as part of the design phase of the project. These surveys are often an essential part of any application for planning permission too.
Surveys definitely play a key safety role in primary industries such as mining, or in other industrial sectors that interact with the land, such as demolition and infrastructure. Businesses in these industries will use surveys to prepare their projects, but also to make sure that they can ensure the safety of their workforce on site.
General topographical surveys are usually concerned with physical features of land although building demolition surveys concentrate on human buildings that are marked for destruction.
Types of Survey
The world of topography addresses a large number of physical characteristics so it is important to determine what type of topographical survey is appropriate for a particular situation.
“Lie of the land” Surveys
These types of topographical surveys are designed to create an overview of the physical properties of any given plot of land. Whilst the information gathered by the survey will be extremely accurate, and can be very extensive, the purpose of these surveys is to give a site summary. They will usually be the first type of topographical survey that is undertaken on a job.
These surveys will generally incorporate a boundary survey that sets out to define the extent of the site and highlight any particular restraints that are determined by the geography of the site. They may also include a level survey that will measure the elevation of the land and the various gradients that exist.
Building Surveys
Building surveys are more typically concerned with man-made constructions on a site, including the surveying of special apparatus and even infrastructure characteristics. This type of study 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 precise plan of the external and internal dimensions of a structure. Depending on the requirements of the job, a measured survey could provide basic building “footprint” dimensions, or might produce a highly detailed plan of the structure. This information can be used to generate internal floor plans and even roof plans.
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 needed so that the demolition firm can plan a demolition that is both adequate and safe. Often these surveys will also be legally required.
Surveys will often contain information about the energy services that are present on a site before any demolition or construction work happens. This is an essential safety factor because any unmonitored destruction to pipes and cables carrying water, gas and electricity could be very dangerous. The information could also be used to plan new structures, based upon the existing availability of these ammenities.
Another aspect of the site survey will often be an inventory of materials 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 timber. By taking an accurate audit of site materials the construction company can more accurately gauge the need to import building resources, or they can re-use the materials on a different project. These surveys can be made pre-demolition and post-demolition.
Project managers may discover financial benefits after topographical demolition surveys summarise supplies quantities available on-site that can be re-used.
Importance of Site Surveys
Possibly the most important reason to perform a topographical site survey is to ensure the health and safety of the individuals who will be doing work on the site. The industrial sectors that most frequently call for site surveys are dangerous enough as it is without having to be concerned about the condition of the ground on which they are working.
Another critical reason to get a suitable survey done is to highlight any potential difficulties that may arise because of the physical characteristics of the area. Particular things will not be evident on the surface of the site and will only be uncovered once digging or demolition has started.
The inventory of site materials, as previously mentioned, can be of great benefit to a demolition or construction company working on a project. Not only are construction materials themselves expensive, but importing them to the site may be a very expensive task in itself. Any time that material can be reused on site offers an opportunity to save development time and money. Only by taking an exact audit of these materials can a company correctly plan its imported material requirements.
Topographical surveys can also highlight other areas that will be of use to the project managers. For example, if the gradients on a site would be prohibitive to certain 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 construction project, the equipment required for the physical surveying of the site and control of the survey data will often be stored on-site. This is obviously a problem when it comes to the demolition period of a project since the equipment is both costly and sensitive. It is therefore sensible to move this equipment off-site during demolition.
Once the demolition has occurred and the site has been deemed safe for personnel to return to it, the surveying equipment can be restored to its initial position on site. This will allow for efficient data gathering to take place for a post-demolition survey, and keeps a single point of contact for anyone who requires the topographical survey information. Most surveying firms will oversee this redeployment.
Experience is often a determining variable when picking a buildings demolition service provider since each job has unique requirements and unique challenges.
Who can Perform Site Surveys?
Since topographical site surveys can play such a critical role in the success or failure of a construction or demolition project it is critical that they are undertaken carefully by the right people. There are different branches of site surveying and each one will have unique certificates associated with it.
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 previous projects.
Who will use the Survey Information?
When an adequate level of information has been accumulated by a site survey it must be handed out to the appropriate people on-site. Who gets which pieces of information will largely depend on the job roles being performed, but can also rely on the stage that a project is at. There will be less need for materials information half way through construction for example.
Project Planners
Project planners will usually require access to all of the information gathered by a topographical survey, though they will particularly need to use information concerning the physical relief of a site before the design phase, and a site materials record before they can prepare the construction phase.
Demolition Experts
Demolition organisations will want to know about the interior and external properties of any building or structures that they are arranged to take down. Whilst every project will have different requirements, demolition experts will typically need to know about the fundamental structure of a building and the materials it is made out of.
Site Engineers
Construction engineers on-site will be mainly interested in the survey statistics about the relief and topography of the site. It is usually the case that they will need to build on a flat surface, so they will use information about the natural lay of the land to calculate what work will be needed to create a stable foundation for any building. They will want this information prior to and in the course of the construction stage of a job.