Are you carrying out subsurface mapping on your upcoming project? If you want highly accurate results, and no costly mistakes, Ground Penetrating Radar (GPR) surveys could be the right solution for your project. 

Subsurface mapping is so important in creating a map of the underground of a work site. Whether you are a developer, an architect, or a planner, you can study the underground properties to determine utility infrastructure including piping, cabling, drains and sewers, etc. It is a crucial part of the process to ensure the building site can be prepared with this information in mind.

GPR surveys are particularly helpful in helping to detect non-metallic objects such as plastic pipes, concrete, or clay. Completing subsurface mapping can save time and money in the long run by preventing costly mistakes that could be difficult to reverse. 

So, let’s prevent any costly mistakes and discover the power of GPR surveys in subsurface mapping.

How does GPR technology work?

GPR technology sends a high-frequency electromagnetic pulse into the ground using a transmitter. The radar signals are then reflected and detected by the antenna.  

Next, the signals are processed and displayed on a graphic recorder. The transmitter and antenna move across the area of interest, and the graphic recorder will create a final radar image. 

This technique is standard in completing our underground utility surveys to ensure highly accurate results. 

A vital component of GPR technology is resolution. Our surveyors are experienced in using a combination of frequencies to produce accurate results. By using a combination of lower frequency and higher frequency antennas, our surveyors can ensure a high resolution but are also able to identify different features and smaller objects.

What are the benefits of using GPR Surveys in Subsurface Mapping? 

There are many advantages to using GPR surveys in subsurface mapping: 

  • Highly accurate results: through their ability to detect both metallic and non-metallic objects. 
  • Cost-effective solution: allows developers to prevent delays and structural damage through thorough planning. 
  • Fast data collection: the high-resolution image is created in a matter of minutes, making it cheaper and safer than radiography. 
  • Non-destructive and safe: you only need single-sided access, making it an ideal solution for public spaces.

How can GPR surveys help you?

There are various ways that GPR surveys are being used in the construction industry. Here are some common applications:

  • Construction details: to determine the general construction such as material, location, and thickness.
  • Concrete mapping: provides clear radar images on thin concrete floors, roads, pavements, walls, tunnels, and balconies to locate and map rebar tendons and conduits.
  • Floor slabs: to identify voids below the slabs to prevent structural damage.
  • Chimney flue location: detects the location of a chimney flue by detecting the change in the material of the masonry wall and flue void.
  • Locating embedded steel in masonry: due to its non-invasive nature it is effective for use on listed buildings.
  • Hazardous waste: detects any hazardous leaks or contamination.

GPR in practice on a level six service avoidance survey

On a large college field in Oxfordshire, we had to detect air raid shelters for a client with short turnaround times. We suggested the level six service avoidance survey due to the tight deadline. 

This project used the Cobra GPR unit to scan the grid at 1m intervals and detect each anomaly or service found. We also used on-site analysis of the RD10000 GPR unit to cross-reference the data collected by the Cobra GPR unit. 

We found the air raid shelters with both GPR units efficiently and accurately. Using GPR surveys in subsurface mapping improved the efficiency and success of the project. Moreover, we completed the project within the client’s deadline and budget.

Considering GPR Surveys for Subsurface Mapping in Your Next Project?

As we have discussed, GPR surveys can provide numerous capabilities and applications in subsurface mapping. From detecting plastic pipes to identifying voids, it is a highly accurate and efficient method. 

The technology is constantly evolving. Researchers and developers are working on novel antenna designs, signal processing algorithms, and advanced imaging techniques to improve the resolution without compromising the ability to penetrate the ground. AI is revolutionising GPR surveys, enabling faster and more accurate identification of subsurface features.

The demand for highly accurate and efficient subsurface mapping is driving the rapid development of Ground Penetrating Radar surveys. If you have an upcoming project you would like to unleash the power of GPR surveys in subsurface mapping, then get in touch with us and we will provide you with all of the information you need to execute your project with success.

Every local area will have utilities located underground beneath the surface, such as water, oil, and gas pipelines, electrical supply lines, telecommunication and data cabling, and more. Safety must be treated as a number one priority in all building projects. Underground utility surveys ensure that existing underground utilities are located, identified, and mapped out before any work commences.  

Underground utility surveys play a key role in ensuring site safety. After all, people’s lives can be put at risk if hazards are not flagged up appropriately beforehand. In addition, errors stemming from a failure to carry out underground utility surveys can affect local residents, and they won’t be best pleased with suddenly having their water or electricity cut off, for example. 


At Midland Survey, underground utility surveys are one of the specialist survey services we provide. We use cutting-edge technology such as electromagnetic locators and ground penetrating radar (GPR) to allow us to conduct underground surveys with pinpoint accuracy. 

Let’s go further into how they contribute to site safety.

Image of underground utilities.

Underground utility surveys protect site workers and local residents from the risk of injuries and fatalities 

Site accidents can easily lead to serious injuries or fatalities. Therefore, one of the principal purposes of performing underground utility surveys is to protect site workers and local residents from the risk of injuries and fatalities. Gas explosions and electrical shocks are examples of two underground risks that come with harmful consequences.  

Under the Health and Safety at Work Act (HSWA) 1974 and the Management of Health and Safety at Work Regulations 1999, construction firms have a duty to ensure the health, safety and welfare of their employees at work. Carrying out an underground utility survey is part and parcel of ensuring everyone’s safety on site. 

Avoiding accidental damage to underground utilities 

Underground utility surveys help to equip everyone working at the site with detailed accurate information regarding where important pipelines, water supplies, sewage, and electrical wiring are located. So, another significant contribution of underground utility surveys to site safety is preventing accidental water main breaks, power outages, and more during the excavation process. 

At Midland Survey, we use the latest technology to deliver GPR Surveys (Ground Penetrating Radar Surveys) for customers. The wonder of GPR technology is that it is a non-invasive method, therefore it doesn’t require any digging or excavation on the site. 

How much do GPR surveys cost?

You may be wondering about the cost of ground penetrating radar surveys. In summary, a GPR survey carried out by industry experts on a simple site could cost approximately £500 – £700 per day, but a larger more complex site could cost up to £10,000. 

Image of GPR survey machine.

Cutting down on delays and Costs

Alongside enhancing site safety, they can help to reduce the potential for delays and costs on a project. 

Time is money in the construction industry, and you don’t want projects being delayed when the situation could have been easily avoided. 

Fixing damaged utilities can gobble into your time and prove expensive. Construction companies can also incur harsh fines and penalties from governing agencies for any utility damage. 

Having access to detailed data from in-depth underground utility surveys will help to prevent the risk of a project being marred by delays and increased costs. At Midland Survey, we offer competitive rates for bespoke underground utility surveys. Get a quote from us today to find out more. 

Improving project design and Planning

Underground utility surveys can lead to improved project design and planning by helping architects and engineers to create better quality more accurate designs. This in turn can make things more efficient by decreasing the need for a long string of design modifications and alterations down the line. 

Are you interested in getting an underground utility survey? If so, reach out to our friendly knowledgeable team today by calling our head office on 01926 810 811 or sending an email to mail@mslsurveys.co.uk

The accuracy of a ground penetrating radar survey is second to none when identifying metallic and nonmetallic utilities and structures without disturbing or digging into the ground. 

Considering the sophistication of the radar technology, what is the actual cost of having a GPR survey carried out? 

What is a GPR survey?

Ground penetrating radar surveys are ideal for avoiding solid and ground disturbance. Using radio waves this geophysical locating technique pin points matter and objects under the surface of the soil. 

Surveyors can use a GPR survey to determine the change in soil profile, pockets of air, the layout of underground pipelines, groundwater tables, rocks, drained water pockets which commonly cause sinkholes and other geological features. 

How much does a ground penetrating radar survey cost in the UK?

If you’ve chosen to have your GPR survey conducted by industry experts in surveying you’ll be looking at spending £500-£10,000 a day

An average price of a complete GPR survey can vary depending on the size and complexity of the site. A simple site such as an open playing field could cost around £500 – £700 whereas a more complex site such as a large industrial site could range up to £10,000. A complicated example would be something like a hospital site where there is likely to be a vast network of services and plenty of anomalies in the ground to discover.

Your project budget is incredibly important to us. That’s why we will always provide you with the right level of survey for your site. 

Get in touch today to receive a GPR survey quote. With Midland Survey you’ll receive prime accuracy with your survey reading which is carried out by a highly experienced surveyor.

How does a GPR survey work? 

By sending high-frequency (50-1500MHz) electromagnetic pulses into the ground, the GPR machine can assess the matter below and create images based on the waves bouncing between the changing materials. 

There are two key elements of the GPR which enable it to give effective and accurate results.

  1. The transmitter  – Responsible for actually transmitting the radar signals into the ground. The transmitter of the GPR is physically held close to the ground when sending the signals.
  2. The antenna  – Responsible for receiving the radar signals back from the ground and configuring the information.

The transmitter and the antenna work alongside each other as they are passed over the site area. The radar signals which are collected through the antenna are then processed through a graphic recorder. 

As the ground is being surveyed, the graphic recorder will generate a 3D cross-section image of the earth showing the inconsistencies of soil and change of density. 

What are the benefits of a GPR survey? 

Our ground penetrating radar (GPR) surveys can aid in identifying previously invisible plastic water and gas pipes, fibre optics and drainage pipes. Here are some additional benefits as to why we use a GPR survey on every site we visit at no extra cost. 

  • Provides a clean sectional view of the earth’s subsurface.
  • Can capture images of concrete, plastic, metal, natural materials. 
  • Is self-contained.
  • Is non-hazardous to the environment or employees.
  • Is quiet and does not disturb workflow.

In addition, it will detect the depth and give an indication of location of the identified items. 

Can a GPR survey work on concrete? 

Yes, a GPR does work on concrete. Construction companies commonly use the system on concrete. A GPR can even be used on reinforced concrete. The purpose of surveying concrete in this precise way is to detect any rebar which may affect any further works.  

How reliable is ground penetrating radar?

Readings can be up to 90% accurate with a highly skilled operator and surveyor. Midland Survey provides an expert team of underground utility surveyors. 

We believe that radio detection equipment and GPR should always be used to give you the most accurate results. For this reason, GPR is used on every site when you choose to have a survey with us. We are also proud to be a part of the European GPR Association.

How can I get a quote on a GPR survey?

Understanding the depth of survey you’ll need requires expert advice and will ultimately affect the cost. Make sure you’re putting your budget to good use and seek the help of experienced industry professionals.

At Midland Survey we are ready to give a quick quote whenever you are. If you have an upcoming project in mind, get in touch. We can advise you on the type of survey you need and execute it with complete precision.

You need to know what’s going on beneath the surface before you embark on a building or construction project. There’s a world right under your feet. Otherwise, the project could interfere with or damage below-ground pipes used to transport water, power, gas or sewage. Arranging an underground utility survey could lower the risks builders, developers, engineers, and utility owners face.

Surveying underground utilities can save both time and money in the long run. Underground utility surveys protect the safety of workers and the public and minimise project delays. In this article, we address how you could benefit from an underground utility survey.

Work man using a spirit level on foundations.

What is an underground utility survey?

An underground utility survey is meant to create a map of precisely which services are underground and where. Developers can familiarise themselves with the whereabouts of subsurface utility infrastructures like piping, cabling, ducts, sewers and drains.

New building or construction work projected for the site can be planned with this information in mind. When developers know the environmental constraints for the project, an array of potential hindrances can be avoided.

How could this kind of underground survey benefit you?

At Midland Survey, our surveyors are trained in creating comprehensive maps of underground utilities located in and nearby clients’ sites. These maps can also be paired with topographical maps indicating the layout of above-ground features on the same site.

Once you have an accurate drawing, you can easily avoid making mistakes that would require a lot of time and money to reverse. For example, you could avert running into legal issues or needing to reschedule any of the work

What is ground penetrating radar (GPR)?

This revolutionary technology works by emitting energy pulses into the ground, where they bounce off buried materials and indicate their locations to the GPR user, who will be moving a transducer or antenna along the ground.

When surveying underground utilities, GPR technology is reserved for detecting non-metallic objects, like plastic pipes, concrete or clay. For locating metal pieces, radio frequency location (RFL) technology achieves more accurate results.

Equipment used in a ground penetrating radar survey.

What are CAT locators?

No, they aren’t quite devices designed to help people find their cats. The ‘CAT’ here is an acronym standing for Cable Avoidance Tool and used in reference to RFL technology that traces signals emitted by targets located beneath the ground.

As RFL only works on targets that emit signals, it can only be used for determining the locations and dimensions of metal objects. CAT tools can thus assist in collecting information about metallic fuel, vent, water and gas pipes as well as metallic telecommunication and TV cables.

What are Genny (signal generator) tools?

These are meant to be operated in conjunction with CAT locators. By passing signals into the ground, a Genny tool can assist the user in more quickly and precisely tracing a range of utilities. Using a CAT and Genny can prove much more effective than using a CAT alone.

This is why, for the task of surveying underground utilities, we use CATs and Genny tools together as standard. However, we also combine them with use of the earlier-mentioned GPR technology so that, for our clients, we map out underground utilities as efficiently as possible.

How can you ascertain the condition of drainage pipes? 

As we have established, an underground utility survey undertaken by our team can help you to discern what and where drainage pipes are. However, you would need a different service to find out about their condition. Fortunately, we offer this service in the form of CCTV drainage surveying.

This would entail inserting a CCTV camera down piping so that, on a monitor, we can see inside the drainage system without any ground being dug up beforehand. This is important because above-ground building work could adversely affect subterranean pipes already in unsatisfactory condition.

Underground drainage pipe system.

What risks could your construction project pose to underground utilities?

As acknowledged earlier in this article, building work above ground can accidentally cause damage to utilities. Even if this work follows suitable protocols, it could compromise any nearby piping that has deteriorated.
The use of heavy machinery can lead to ground subsidence damaging such pipes. You could therefore counter this risk by having affected piping relined — one kind of drainage repair work Midland Survey can complete in a non-intrusive fashion.

Are you intent on a building or construction project?

It is essential that you organise an underground utility survey in advance. The mere presence of underground utilities can have major implications for the planning and design stages of a project.
From surveying underground utilities on behalf of clients, we accurately record the locations of gas pipes, fibre optic cables, communications cables, and subsurface infrastructure. Clients can easily contact us to book an underground survey. Get in touch today to find out more about how we can help you.