Demolition Surveys

The demolition industry has a certain reputation for being a harsh atmosphere in which brute force takes precedence over calculated thinking; however this impression is far from correct. There is a huge amount of work that goes on behind the scenes of the demolition and construction sector which is firmly rooted in the academic arena.

One part of this unnoticed work is site surveying, or more specifically pre-demolition and post-demolition topographical surveying. This sort of work demands a great balance of specific technical know-how as well as experience of the industry and a genuine intuition for the intricacies of the job.

Topographical Surveys

A topographical survey is a report of the actual features of a given plot of land. The aim of a topographical survey is to chart the naturally occurring and man-made traits of a particular landscape to a high degree of precision.

Topographical surveys can be carried out on a very wide range of landscapes, 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 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 outlined below.

Common Applications for Topographical Surveys

Perhaps the most widely used, and most generally recognised application for topographical surveys is cartography, or map making. Modern maps include a great amount of information about the terrain they relate to, including waterways, elevations and ground surface, all of which will have been gathered via a topographical survey.

Topographical surveys also have a key role to play in the construction industry. When people or organisations are looking to build any kind of structure they will need to perform extensive surveys as part of the design phase of the project.

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

Though it is not always the best option, a demolition survey may always be performed whilst preparation work is occurring on-site.

Types of Survey

The world of topography addresses a large number of physical features so it is important to identify what type of topographical survey is suitable for a particular scenario. A few of the more typical types of survey necessary for construction sites are discussed 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. Whilst the data collected by the survey will be very accurate, and may be very extensive, the purpose of these surveys is to provide a site summary.

These surveys will usually include 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 measure the elevation of the land and the numerous gradients that exist. Any 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 machines and even infrastructure characteristics. This type of study is more regularly associated with the demolition industry because it can give a detailed plan of the structure to be demolished. It may be used for other projects as well.

A building survey will almost certainly include a measured survey, which involves creating a precise plan of the exterior and internal dimensions of a structure. Depending on the requirements of the project, a measured survey could provide simple building “footprint” measurements, or might produce a very detailed plan of the structure. This information can be used to produce internal floor plans and even roof plans.

Content of a Topographical Site Survey

A survey of a demolition site will almost always include the details gathered by the types of boundary and building surveys mentioned above. This information will be necessary so that the demolition firm can plan a demolition that is both satisfactory and safe. More often than not these surveys will also be legally requested.

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 factor since any unmonitored damage to pipes and cables carrying water, gas and electricity could be very dangerous.

Another aspect of the site survey will often be an audit of resources on the site. This type of survey will be a quantity survey of the various types of materials that can be found on site, for example, tiles and masonry, concrete that can be used as hardcore or even wood. By getting 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 job. These surveys could be made pre-demolition as well as post-demolition.

Undertaking a rigorous and comprehensive house demolition survey ensures the protection of people in the immediate vicinity of the work site.

Importance of Site Surveys

Perhaps the most significant reason to perform a topographical site survey is to ensure the safety of the people who will be doing work on the site. The industrial sectors that most commonly call for site surveys are risky 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 identify any potential difficulties that may arise because of the physical properties 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 started.

The inventory of site supplies, as previously stated, can be of great benefit to a demolition or construction company working on a project. Not only are construction materials themselves costly, but transporting them to the site may be a very expensive task in itself. Any time that material can be recycled on site provides 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 particular vehicles or machinery then a new entry route or alternative machinery will need to be found. Equally, an appropriate site will need to be found for the base of control operations for the project. Good site surveying can help out in these less tangible ways.

Positioning of Survey Control

During the surveying and construction phases of a construction project, the equipment required for the physical surveying of the site and control of the survey information will often be stored on-site. This is obviously a problem when it comes to the demolition stage of a project since the equipment is both costly and sensitive.

Once the demolition has taken place 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 effective data collecting to take place for a post-demolition study, and keeps a single point of contact for anyone who needs the topographical survey information.

The demand for strict control as well as preparing is critical in garage demolition projects given that houses and other buildings may be close by.

Who can Perform Site Surveys?

Since topographical site surveys can play such a crucial role in the success or failure of a building or demolition venture it is critical that they are undertaken thoroughly by the correct people. There are different divisions of site surveying and each one will have unique qualifications associated with it. Getting surveyors with these specific qualifications will certainly be advantageous.

When selecting a company to undertake the surveying work necessary for your project it will be sensible to choose a company with a good reputation and a proven track record. Ask to see examples of their previous work and try to get 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 personnel on-site. Who gets which 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 require access to all of the information gathered by a topographical survey, although they will particularly need to use information regarding 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 external characteristics of any building or structures that they are arranged to take down. Whilst every job will have different requirements, demolition experts will generally 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 particularly interested in the survey statistics about the relief and topography of the terrain. It is usually the case that they will want to build on a flat surface, so they will use details about the natural lay of the land to calculate what work will be needed to create a steady foundation for any building. They will want this information prior to and in the course of the construction stage of a job.