The Guide to Construction Pre-Task Planning (PTP)

SAFETY PLANNING

The Guide to Construction Pre-Task Planning (PTP)

Pre-Task Planning (PTP) helps identify hazards and implement safety measures before work begins, ensuring a safer, more efficient job site. By planning ahead, teams improve communication, reduce risks, and enhance productivity.

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What is Pre-Task Planning (PTP)?

Pre-Task Planning (PTP) is a proactive safety practice designed to identify potential hazards and mitigate risks before work begins. It’s an essential process for improving safety, ensuring compliance, and enhancing productivity on any construction site.

How Does PTP Work?

PTP involves assessing specific tasks and potential risks to create a comprehensive plan that prioritizes safety management. The process is broken down into three key steps:

1. Before the start of any task or job, the supervisor/employee (or whoever is in charge of the project) needs to identify three main things:

  • The task(s) that need to be completed that day.
  • The potential hazards that could be involved in the completion of those tasks.
  • The corrective measures that will be put in place to avoid/mitigate the identified hazards.

For example, let’s say the project task is to flat saw a six inch thick slab of concrete. One of the first things that need to be done is for the supervisor or person in charge of the project, to walk the site with the customer (and walk the site solo) to identify potential hazards, such as:

  • Underground services: Typically when cutting concrete, Penhall Company Concrete Cutting Professionals are continually exposed to gas lines, water lines or electrical lines that could be under the concrete or asphalt or embedded in the concrete.
  • Traffic: If the work is conducted on a street or near an area where people are driving, the crew needs to determine what kind of barriers or work area delineations need to be put in place to protect the safety of the workers and drivers.
  • Pedestrians: Work that is conducted in public areas can expose both workers and bystanders to harm (e.g. flying objects, slip/trip hazards, exhaust fumes, etc.).

2. Once all the potential hazards have been identified, measures must be put in place to control the hazards.

For example:

  • Underground services: Call 511 (number for dig alert) and have someone come out and identify what’s underground and where it’s at.
  • Traffic: Put a truck between worker and traffic; delineate the work area using cones, etc.
  • Pedestrians: Use spotters to keep unauthorized people out of the work area; vacuum slurry water immediately; etc.

3. Pre-Task Planning is also applied to the tools and equipment used on the job and the personal protective equipment (PPE) that the crew wears and uses.

It’s important to remember that PTP should also be applied to tools, machinery, and personal protection equipment (PPE). Identifying the potential hazards related to equipment and verifying that corrective measures are in place is an essential part of ensuring safety, productivity, and morale. This proactive safety approach helps mitigate potential risks and enhance compliance with safety standards.

For instance, if a blade is used, one of the corrective measures to prevent someone getting cut would be to use a blade guard and to inspect the structural integrity of the blade guard.

In addition, if a situation changes while the job is underway, all workers must take a “time-out and stop work,” to conduct a new PTP to evaluate the changing hazards and to assess whether the existing corrective measures will sufficiently mitigate the hazards, or if new corrective measures need to be implemented. This ensures that the job hazard analysis (JHA) remains relevant and effective.

Here are a few examples of questions that operators should ask themselves during their PTP process to validate that the equipment is in good condition and functioning properly before it gets to a customer’s location or job site.

Flat Saw:

  • Does the engine have oil?
  • What is the hydra drive fluid level? Is that sufficient?
  • Does it lift and lower smoothly?
  • Are the blade guards in place?

Small Gas Powered Equipment:

  • Is the oil level sufficient?
  • Is the On/Off switch working properly?
  • Is the battery and connections functioning properly?

Hydra Pack:

  • Is the engine oil level ok?
  • Are the remote and override switches ok?
  • Are there any leaks?
  • Is the GPM flow adjusted to match the tool?
  • Is the PSI adjusted to match the tool?

Core Drilling:

  • Is the carriage tight on the mast?
  • Does the carriage have all the handles and rack gear? Are they ok?
  • Are the base adjusters in place?

Trailers:

  • Is the tire pressure adequate?
  • Are the tires in good condition? What about the rims?
  • Do the springs have defects?
  • Is the pintle eye in good condition?
  • Is the ball/pintle hitch attached and locked?
  • Is the coupler in place?
  • Are the lights working?

Wall Saws:

  • Is the carriage tight on the track?
  • Are the output/blade shaft threads ok?
  • Are the factory guards in place and ok?
  • Are the blade flanges and keyway ok?
  • What is the condition of the hoses? Is it sufficient?
  • What is the condition of the electric cables and plugs?
  • Are there any cracked swivels?

Hand Saw/Chop Saw:

  • Are the factory blade guards in place?
  • Is the output/blade shaft ok?
  • Is the trigger clean and operating freely?

Diamond Tools:

  • Is the proper blade guard installed?
  • Is the blade/core free of cracks?
  • Is the blade flat and positioned to run at the selected RPM?
  • Does the saw/shaft speed match the blade specified RPM?
  • Is the blade rotation correct?
  • Is the core bit RPM set to match the diameter and application?

4. Who is responsible for Pre-Task Planning?

Effective task planning involves all team members to ensure comprehensive safety management.

If the job is a contract job or a job that is managed by a supervisor, the supervisor will create his/her hazards list and corrective measures. Then, during the morning “Pre-Task Planning” meeting, the supervisor will review the day's plan, hazards and corrective measures and then seek input from the crew and ask if there’s anything on the PTP that they think has been left out or overlooked or needs to be added. This gives the employees the opportunity to contribute to the planning of the project that they will be working on.

However, if an hourly service employee is working independently on a job, they will create their own PTP documents.

Benefits of Pre-Task Planning

Pre-Task Planning offers numerous benefits beyond just keeping people safe. It significantly enhances project efficiency and overall success. By taking the time to plan ahead, teams can identify potential bottlenecks and address them proactively. This leads to smoother operations and fewer unexpected delays.

Moreover, PTP fosters better project coordination. When all team members are involved in the planning process, it ensures everyone is on the same page regarding tasks, potential risks, and mitigation strategies. This open communication builds a stronger, more cohesive team that can work together more effectively.

PRE-TASK PLANNER

Physical Hazards

  • Falling Objects
  • Sharp Objects
  • Walking and Working Surfaces
  • Impact From or By
  • Work Over or Near Water
  • Heavy Lifting
  • High Noise
  • Hot Surfaces

Task Specific Hazards

  • Fall from Height 6 Ft.
  • Scaffolding
  • Climbing Ladders
  • Electrical Energy
  • Excavations and Trenching
  • Confined Space Entry
  • Slips, Trips and Falls
  • Moving Machinery
  • Hand Power Tools
  • Raising and Lowering Materials
  • Floor or Wall Opening
  • Traffic
  • Pinch or Crush Points
  • Machinery Operations

Traffic and Pedestrian Control

  • Signage and Barricades
  • Flag Person
  • Arrow Boards
  • Delineations
  • Traffic Control Plan

Fall Protection and Prevention

  • Full Body Harness
  • Fall Plan
  • Vertical Life Line
  • Guard Rails
  • Retractable Lanyards
  • Lanyards
  • Hole Covers and Barricades
  • Control Access Zones

Excavation and Trenches

  • Competent Person
  • Escape Ladder
  • Barricades and Plating
  • Shoring, Sloping and Benching
  • Signage and Cones

Confined Space Entry

  • Permits Completed
  • Crew Trained
  • Ventilation
  • Atmosphere Monitored
  • Rescue Plan

Emergency and Medical

  • First Aid Kit
  • Call 911
  • Call Dispatch

Health and Housekeeping

  • Trash and Debris Contained
  • Liquids Available
  • Respirator Clean
  • Heat Stress

Preparing for the Unexpected

While thorough Pre-Task Planning significantly reduces risks, it's impossible to predict every scenario. That's why it's crucial to have backup plans in place. Consider potential delays or issues such as adverse weather conditions, equipment breakdowns, or absent employees.

By being proactive and having contingency plans, you can reduce stress and resume progress quickly if unexpected issues arise. This level of preparedness not only enhances safety but also demonstrates professionalism and commitment to project success.

Remember, the goal of Pre-Task Planning isn't just to complete paperwork—it's to create a safer, more efficient work environment for everyone involved. By consistently applying these principles and remaining vigilant, we can all contribute to a culture of safety in the construction industry.

Stay safe!

Our team is busy completing demolition work on the I-90 Bridge over Rainier Ave.

Stay tuned for the full story…

In the meantime, check out this short video highlighting our work thus far!

Are you wondering if you need to use private utility locating services? Here are the most common reasons why our clients hire us for their locating needs.

811 won’t do the utility location.

811 is a public utility locator. They can locate all utilities from the street to the meter. Any utilities in your private property would need to be located by a private utility locator, such as Penhall Technologies.

They already hit a utility.

Oftentimes, our customers will call us because they started excavating without scanning first and hit a utility line. Therefore, they want us to scan the rest of their property to prevent any further damage. Striking a utility line can be costly and can result in injury.

They called someone else and they were unsuccessful.

This scenario goes hand in hand with the reason previously mentioned. Sometimes our clients do scan. However, the company they selected didn’t provide accurate markings and the client struck a utility as a result. Our analysts complete extensive utility locating training. They are trained to properly mark your site, provide written reports, and to provide you with the best service.

Home improvements.

It is always important to locate all utilities before doing any projects that require digging or excavating. This includes, but is not limited to: landscaping, fencing, pool installation, installing a mailbox, deck installation, among others.

Water leaks.

A lot of our clients suspect that they are dealing with a water leak. While we can’t locate the water leak itself, we can help you locate the water line and look for signals of wet soil that may indicate the location of the leak.

If you would like to schedule private utility location, or need assistance determining if private utility location is right for your projcet, please give us a call at 1-800-736-4255 or fill out our contact form.

underground utility locating

Our South Carolina Analyst started the year with an interesting project, locating unmarked burial sites. A church wanted to know the location of all possible unmarked burials to update the information they have on available space.

Ground Penetrating Radar (GPR) is a method of inspection that is highly useful for this type of project. Using GPR utility locating equipment, any buried objects would reflect on the screen as a parabola as they were passed over above ground. Our analysts are expertly trained to interpret this data, which enabled South Carolina analyst to mark where the graves were with flags in real time.

Our analyst scanned one half of the small cemetery, this totaled to approximately a half acre of land. He used the GSSI SIR 4000 with a 400 MHz antenna to image the subsurface within the cemetery. The analyst found a total of 57 unmarked graves.

The analyst’s expertise is key in differentiating between old and new graves. Main components to look for is soil and reflections of the objects on the equipment’s’ screen. When looking at a newer grave, the soil appears to be collapsing. This suggests that its relatively young compared to the other burial sites.

ground penetrating radar

Additionally, the strength of the reflections would be the second clue; the newer burial sites reflect back with very high amplitude. On the other hand, the older sites do not reflect back as strongly. Perhaps, the reason for this is that different burial techniques were in practice between the times the bodies were buried.

Penhall Technologies has the expertise to complete any kind of project. From utilities to unmarked graves, we have the knowledge and equipment to complete an array of jobs. Contact us with information about your project and we will identify an approach on how best to assist you.

X-ray scanner setup on site

You are ready to inspect the concrete for your project using digital concrete x-ray. However, you may have heard or read some information about the service before. This could make you hesitant or not fully confident in this state of the art service. We want to clear up any doubts and address the most common misconceptions about digital concrete x-ray.

Digital Concrete X-ray is dangerous

This service isn’t dangerous when performed by expertly trained operators and executed in accordance with state regulations. Our operators receive extensive training that covers safety parameters, proper setup, and how to operate the digital x-ray machine. This ensures that only the safest levels of radiation are emitted. The levels emitted with proper operation are far below state-level allowances. Because radiation is involved, we perform job walks to determine safety parameter zones for trades, employees, or bystanders on site.

Digital Concrete X-ray is better than GPR

These two services have the same purpose, but they are used very differently. While digital concrete x-ray may be the best choice for your project, GPR could be better for someone else’s project. A couple of things to ask yourself before pursuing digital x-ray are:

  • Do I have access to both sides of the slab?
  • Do I need an exact picture of what lies within the concrete? Or am I okay with an analyst interpreting GPR data that is collected?
  • Is my slab less than 12” thick?
  • Can I vacate a safety parameter zone near the x-ray site for a short period of time?
  • Do I suspect the slab to be highly congested?

For highly congested areas or where there is no room for data interpretation, we do recommend digital concrete x-ray. In some cases, we have used GPR and found the area to be too congested. After this, we suggest x-ray to our clients. This is just an example, but it is not always the case. Both are dependable methods of concrete inspection.

Results delivery can take a while

This misconception is very common. With digital concrete x-ray, the truth is very far from this. This service delivers a real time image. Picture the whole process as taking a picture of a landscape. Here, we do the same, but we image the interior of the concrete instead of the landscape. With this service, it is possible to know what is inside the concrete in a very fast manner; 5-10 seconds.

Currently, Penhall Technologies offers Digital Concrete X-ray services in San Francisco-Bay Area, Los Angeles, San Diego, and Las Vegas. We have plans to expand into more areas soon.

Did we answer all your questions or concerns? If not, contact us at gpr@penhall.com, or give us a call at 707-363-9822.

concrete scanning for rebar

A lot of underground hazards lie beneath the surface you will be working on. It is essential to scan first to avoid all of the following scenarios we will touch on.

Hitting a utility line

Hitting a utility line during any type of excavation can result in great costs for those involved. To start, it can cut out the utility service for you and/or your community. According to a CBS News article, you could face fines from local regulators. Moreover, all repair costs, from fixing the damaged utility line to any damages done to neighboring homes or businesses, can fall on you.

You can also encounter physical injury costs for you or the workers performing the excavating. Some utilities can be dangerous for the person working, such as steam, gas, propane, and electricity, and communication lines.

Striking a post tension cable

If scanning is not performed before construction, you risk the chance of cutting into post tension cable. In a FLCAJ article, Richard Slider of Slider Engineering mentions that post tension cable release can cause structural damage to a building, as well as injury to workers. They also mentioned that the cost of a single cable repair ranges from $800 to $1,200. This does not include the cost of other repairs of areas affected by the release.

If a worker accidentally cuts into post tension cable, the cable reacts by snapping. In the past, workers have been badly injured or even killed due to this release.

Cutting into rebar

During construction, you also run the risk of damaging rebar. According to BNProducts, cutting into rebar can have serious consequences for your project. First of all, you can expect injuries for your workers. Sometimes, when you drill and hit into rebar, pieces of debris can fly out and strike workers. In addition, cutting into rebar can lead to extensive repairs that can keep your project behind schedule.

It is also important to be aware that cutting into rebar can cause serious damage to the structural integrity of the concrete. This can make your site too unstable to work on and further delay the completion date.

“Now many industry experts recognize that cutting into these hazard types can be devastating if people do not scan first. GPR technology is a real game-changer for safety,” said Penhall Technologies President, Simon James. If you want a safe and timely construction project, contact us for our concrete scanning and underground utility locating services.

scanning concrete on boom lift

Our Santa Clara office performed concrete scanning services for a local overpass project. The bridge needed a new water pipe installed. This pipe had to be installed on the side of the bridge due to seismic regulations. To ensure safety for everyone involved, the client requested Penhall Technologies to scan the concrete beforehand.

The scanning was done from a vehicle mounted boom lift. This type of boom lift is not commonly available, the one used on this project was brought in from Oregon. The vehicle was set on the bridge. With the boom lift on it, our analysts performed the scanning overhead.

concrete scanningThis system worked in a very particular way. The truck had a camera and a microphone that allowed the analysts and the driver to communicate. Depending on the required scan areas, the driver moved the boom lift accordingly. The entire scan job was done using this unique mobile system.

Our Santa Clara analysts scanned 18″ × 24″ areas in two phases. For phase one, they scanned 26 areas. For the following phase, they scanned 20 areas. The concrete scanning itself took a week to complete. Our analysts found rebar in the slab, but no conduits or cables were present.

For Penhall, as well as for our client, safety was the main priority. Our analysts regularly attend safety trainings that involve boom lifts. This particular project was done over water. Our analysts had morning and evenings safety briefings, as well as very thorough walk out inspections. Moreover, the vehicle mounted boom lift was inspected both in the morning and after their regular lunch break. As a result, the analysts completed the scan safely.

After the scanning was completed, Penhall Company performed the core drilling without striking any rebar. This confirms our analysts’ accurate findings and markings done on this project.

Our analysts are expertly trained to handle any construction project, such as this one, and bring you precise results that will keep your project safe.

Anaheim demolition

Construction has begun for a new luxury Westin hotel in Anaheim, CA. The project is taking place at the previous location of the Anabella Hotel, which Penhall took down to make room for the $245 million project. The project is expected to be completed by 2020.

Penhall Company worked in the early stages of demolition for the Anabella Hotel. In addition, we are performing hazardous material abatement, structural demolition, removal of all of the pools and flatwork, and clearing and grubbing the site for trees, roots, etc. Essentially, we are clearing the entire 10 acre site down to dirt for the new hotel.

Once completed, the hotel will meet all requirements for a four diamond rating. Currently, Anaheim only has two luxury hotels – both in Disney’s property

Anaheim demolition

The hotel totals 42,000 square feet, including 613 rooms, 101 suites, three restaurants, a pool, roof-top lounge, and 11 meeting rooms. The hotel will generate jobs for 600 people, 450 of those will be full-time positions.

Demolition has always been a core competency of Penhall. We make it our business to supply safe, scalable demolition services for a wide variety of applications. With every structural demolition project, Penhall’s priorities are to minimize risks, maximize productivity, and ensure zero lost time.

concrete scanning terms

Concrete scanning and underground utility locating are a must when performing any excavating, coring, drilling on concrete or on any other surface. If you are still deciding whether or not to utilize this service, this list will help you understand our blogs and information easily.

GPR: This stands for Ground Penetrating Radar. GPR is a method that uses radar pulses to image the subsurface. A GPR system is made up of three main components: a control unit, an antenna, and a power supply.

Subsurface object: These are objects that the GPR system can find. For example, rebar, post tension cable, wire mesh, utility lines, among others.

Conductivity: Conductivity defines a material’s ability to conduct electricity. The differences in the conductivity of materials determines what shows on the equipment screen.

Hyperbola: When an analysts is scanning and he/she finds a buried object in the ground or concrete, it will show up as a hyperbola on the equipment’s screen.

Antenna: Component of the GPR system. The antenna captures the pulses emitted into the ground to reveal a real time image of subsurface objects found.

Electromagnetic field: Used for utility locating, an electromagnetic field occurs when a current is running through a transmitting line. This could be an electrical cable or communication line. The analyst could artificially create an electromagnetic field by using the equipment if the utility does not have an active current.

Public utility locator: 811 is a locating company that identifies all public utilities (utilities that go from the street to the meter). They are the federally designated call before you dig company that helps homeowners and professionals avoid damaging vital utilities when digging or excavating.

Private utility locator: Contrary to 811, a private utility locator will scan all underground utilities on private property. For example, a backyard or a driveway. Penhall Technologies is a private utility locator.

Utility markings: After scanning, the analyst will mark the utilities found with chalk, tape, or keel. These are utility markings and serve as a guideline for your project.

APWA color chart: Each utility marking has a designated color. This depends on what type of line the analyst is marking. This is the official color chart from the American Public Works Association.

 

Want to learn more about concrete scanning and underground utility locating? Review our in depth slides on LinkedIn’s Slideshare.

Texas utility locating
The Use of Utility Locating Services in Hurricane Harvey’s Relief Efforts

Last week, Penhall Technologies had the opportunity to participate in the efforts for those affected by Hurricane Harvey. We performed our services at the NRG Center in Houston, which hosts the largest emergency shelter in the city.

First of all, the FDNY Incident Management Team called our Houston office for utility locating services. The New York Fire Department hired them to set up a 40’ x 100’ tent. This tent would function as the main location to serve meals to truck drivers delivering supplies for the emergency shelter itself. The NRG stadium expected over 250 truck drivers coming into Houston to deliver these supplies.

Before installing the tent, they decided to scan the proposed location for it. This was about 85,000 square feet. The scan would ensure that the client could install the tent safely, without striking any subsurface hazards. The location for the scanning took place in the parking lot.

Two of our local Houston analysts scanned for all utilities under the asphalt. They used Ground Penetrating Radar with the SIR 4000 antenna and electromagnetic detection technology through the use of the RD 7100 wand. Then, they found and marked out two utility lines. These were a sewer line and a power line.

These lines did not present any issues for the client. The analysts advised to stay a minimum of 3 feet away from the marked utilities. Due to this, the client had plenty of room left to drive the tent’s posts into the ground away from the marked lines.

Harvey utility locating

“Being able to help my community here in Houston is beyond rewarding. Helping with the utility locate at NRG makes me feel as if I’m having a direct effect on the city that I grew up in. The fact that I can give back and aid my fellow Houstonians in a time of adversity is indescribable,” said GPR analyst Jacob Paddock.

The FDNY Incident Management Team was pleased with the locating services. Since then, we have performed another locate for them in Rosharon, Texas before the installation of more tents. Their needs change daily. Therefore, they have been in constant contact with Penhall Technologies.

As a team, we are proud that our services played a role in the relief efforts. In addition, Penhall will continue to assist in any efforts that aid Texas’ recovery. To donate to those affected by Hurricane Harvey, click here.

concrete scanning

Concrete scanning is a method that finds subsurface hazards through the use of GPR (Ground Penetrating Radar). Some of the objects that GPR detects during scanning include: pipes, conduits, post tension cables, utilities, live wires, rebar, and voids, among others. But, why is it important to find and identify these objects?

Safety

When cutting into concrete without scanning first, there is a possibility that you will encounter a subsurface object or hazard. In some incidents, hitting an object can injure the workers at the jobsite. For example, cutting into a post tension cable. The released tension after the cut can cause the cable to snap or expand, causing a blowout. In addition, your workers could be electrocuted by striking a live conduit.

Time

Striking any subsurface objects can result in delays for your project. Quite often, clients call us after they have hit an object in the concrete. Unfortunately, they have learned the hard way. Now they have decided to scan the rest of their project to ensure that it doesn’t happen again. Other times, the repairs needed to fix the damage that has occurred can cause delays. Avoiding these incidents will help to ensure that you can complete your project on time.

concrete scanning markings

Money

Without hiring scanning services before, one may assume concrete scanning is simply an additional cost to a project. In reality, scanning offers a significant cost savings! By having a clear picture of a proposed cut, core, or trench area, you are no longer playing a guessing game. This provides a tremendous financial benefit by preventing repairs and additional services that result from striking a subsurface object. As mentioned before, concrete scanning helps your projects stay on time. Whereas a project that encounters delays can cost more money.

Accuracy

One of the most significant benefits of concrete scanning is accuracy. You can proceed with your project knowing that the proposed layout areas for any drilling, coring, or cutting are safe. On many projects, our analysts find hazards in the layout proposed by the client. If the client hadn’t decided to scan, there is a possibility they would have encountered many of the problems mentioned.

For these four reasons, concrete scanning is a vital method for your project. At Penhall Technologies, we value your time and safety, so we make sure that our services convey that to your project.

concrete scanning

Deciding to scan concrete for your project was a smart decision for many reasons. It saves you time by knowing where to exactly cut, drill, or core. It saves money by preventing damages. And, most importantly, it keeps your project safe. Now that you want to move forward with our scanning services, here is what you should expect.

One of our expertly trained GPR analysts will arrive at the jobsite. Before they start scanning, they will meet with you to discuss the areas that you want scanned. You would need to provide a layout for the analyst to scan.

After this, the analyst is ready to scan. GPR (Ground Penetrating Radar) is safe to use during regular business hours. This means that any trades on the jobsite can continue with their job while the scanning takes place.

The analyst might use different types of equipment depending on the job itself. Our analysts carry the GSSI Mini XT. This equipment is ideal for locating rebar, conduits, post-tension cables, voids, and real time determination of concrete slab thickness. They also use the GSSI 2000 MHz palm antenna. This equipment works in small spaces, approximately 2” from the wall. In addition to the GPR equipment used, all analysts are also equipped with an RD 7100 unit. This unit is ideal for locating live conduits within walls, slabs, or ceilings.

concrete scanning marks

While the scan takes place, the data shows up in real time. Our analysts can interpret the data and from there he/she can mark any objects directly on the concrete surface with tape, chalk, keel, or markers (as pictured above). Then, the analyst would communicate their findings with you.

Sometimes, the proposed layouts are clear and ready for coring or drilling. Some other times, the analyst finds post tension cable, rebar, or other objects in the area where the coring or drilling is proposed. If this is the case for your project, you can propose a second layout location. The analyst will then proceed to scan that area to make sure that it is clear and safe.

After the scanning, a summarized written field report of the findings will be provided you. With this piece of information, in addition to your field markings, you can make decisions as to where to cut, core, or drill. Additional electronic reports are also available upon request, including pictures and 3D scans. These reports take additional time and will be completed off-site and will be emailed to you.

Now you know what to expect when hiring Penhall Technologies for our concrete scanning services. When our analysts arrive on site, you will find that you have gained a trusted partner who will undoubtedly add value to your project. Regardless of the project scale, our analysts always come prepared and ready.

private utility locator
GPR analyst using the RD-7000 for utility locating

When conducting underground utility locating services, Penhall Technologies uses two types of technology: Ground penetrating radar (GPR) and electromagnetic detection (EM). Both of these are great resources for locating underground utilities.

GPR locates underground utilities by emitting radar waves into the ground. These waves pass through the substrate and reflect off of objects that vary in dielectric from that of the surrounding earth. Ground penetrating radar works best when you need to locate: buried pipes, cables, underground storage tanks, etc.

On the other hand, electromagnetic induction detects electromagnetic fields. A magnetic field occurs when a current is running through a transmitting line such as an electrical cable or communication line. The EM unit can detect both passive and active signals.

A passive signal is when a utility, such as an electrical line, is currently turned on and is generating an electromagnetic field. An active signal is when a line is not turned on, and a temporary tone is induced into it. This creates a temporary electromagnetic field. The, the EM unit can detect this field.

Recently, our analyst put to use both technologies for a utility locating job. An electrical company contacted us for a project at a medical facility in the city of Seattle, Washington. The electrical company was in charge of rerouting electrical lines through the parking lot of the medical facility.

utility locating
Analyst marking underground utilities

The analyst initiated the scanning and set a dielectric based on the known soil conditions of the area. He conducted GPR first, utilizing the GSSI SIR3000/400MHz antenna combo. The analyst knew that once he completed the locate , the cut and excavation performed by Penhall Company would not go any deeper than three feet. The survey covered not only the requested area, but a much larger area as well to confirm the location of all subsurface hazards.

The analyst marked out several suspected utilities and an area of shallow root systems, despite needing to work around parked vehicles, tight quarters, and raised landscaping beds.

The analyst used electromagnetic detection equipment after the scan. He swept the area with the RD-7000 to ensure maximum accuracy. From this, the analyst located one additional electrical utility. This particular utility was either too small or too deep to see with the GPR equipment. This is why we provide our analysts with both technologies. It makes us the ideal private utility locator.

Penhall Technologies employs multiple technologies for your utility locating needs, making sure that you finish your projects safely and on time.

Additional Links:
https://electricalschool.org/

GPR - ground penetrating radar service
GPR analyst on a concrete scanning job

 

Now that you have decided to scan first, you might be wondering what suits your project’s needs: Ground Penetrating Radar (GPR) or digital X-Ray? Penhall Technologies offers GPR services nationwide, and X-Ray services in Seattle, San Diego, and Los Angeles. Both concrete scanning methods help you locate subsurface objects and hazards. However, they are both unique, and have different uses.

More often than not, GPR would be the first step to locate any subsurface objects in concrete. GPR analysts start by marking the desired area, which the customer provides a layout of. Then, the analyst proceeds to scan with a handheld device (see picture above). Based on the collected and analyzed data, the analyst would mark the objects found with chalk, keel, or tape. This process goes smoothly under ideal concrete circumstances.

There are a few factors to consider when seeking GPR or digital X-ray services. First, what concrete structure or structural components are being scanned. Digital x-ray is not an adequate option for your project when you are looking to identify objects or hazards in a slab on grade. Digital X-ray requires both sides of the location in question, such as a slab, column, or beam.

The second factor to consider is the location of the project.  If patrons, occupants, or employees are present at the jobsite, GPR scanning can be done during regular business hours. People don’t need to vacate the area. This is ideal for projects and renovations in sites such as hospitals or hotels, where people may be regularly coming and going.

Penhall's GPR analysts
Penhall Technologies’ analysts demonstrating digital x-ray

Sometimes, after completing GPR concrete scanning, the results may show a highly congested area. This means that the analyst collected data that may be extremely difficult to interpret. This leads to inconclusive labels for field markings. This is when digital X-Ray comes in.

Digital X-ray shows a clearer depiction when it comes to imaging the interior contents of an area that’s congested. For this reason, this method is preferred under these circumstances.

Digital X-Ray is not always a service that follows GPR concrete scanning. We recommend pursing digital x-ray as an option when the jobsite in question is highly congested with structural components such as rebar, wire mesh, and tension cables. Or when you simply want a clear precise image of the area.

Both GPR and X-ray can provide valuable information prior to cutting, sawing, or drilling. It will also keep your project on time, on budget, and most importantly- safe! For more information regarding GPR and digital x-ray scanning services, give us a call at 844-211-5300.

Penhall analyst conducting concrete scanning
Concrete Scanning Using Ground Penetrating Radar (GPR)

Ground Penetrating Radar (GPR) is a very effective scanning method to ensure safety when coring or cutting into concrete. However, there are still a lot of misconceptions about what GPR can and cannot do. This list will help you understand GPR before you hire a concrete scanning service for your project.

I can scan myself if I buy the equipment

While setting up and using the GPR equipment is easy, interpreting the data is complicated. A major misconception is that GPR shows a clear image of what is in the concrete. Actually, the screen reflects a black and white image resembling TV static. When the antenna picks up on an object, it reflects as a hyperbola on the screen. GPR analysts go through extensive training to be able to interpret the data, and to know how to differentiate between objects on the screen.

GPR can be successful under any surface condition

Moisture in concrete plays a huge role in the success of concrete scanning. Moisture raises conductivity, meaning the equipment’s signal bounces right back, making it difficult to get good data readings. Concrete that is less than three months old has a higher moisture content than concrete that has had more time to cure so it’s best to wait before scanning. Other difficult surfaces can include insulation, marble, granite floors, among others.

underground wire locating
Analyst performing underground wire locating

GPR can scan at any depth

The GPR equipment in concrete scanning applications is only able to scan up to 20 inches. If we have access to both sides of the slab, then the analyst would be able to scan thicker concrete.

The GPR equipment can differentiate between objects

As mentioned before, the screen of the equipment shows data in a very general state. Different objects, such as post tension cable or rebar, aren’t displayed in a distinctive way, nor do they show a difference in the hyperbola. Thanks to the expertise of the analyst, he/she can distinguish between the different lines and patterns to read the data.

GPR is 100% precise

While GPR is considered to be one of the most effective forms of non-destructive testing, it is not perfect. GPR is as accurate as one-fourth of an inch from the center of the target and less than half-inch in depth under ideal circumstances (for example, well-aged concrete). Some of the variables in the concrete that affect accuracy can be: wire mesh, pan decking, and multiple layers of rebar.

We hope that this list gave you a better understanding of GPR concrete scanning. By deciding to scan the concrete at your jobsite, you are reducing safety and financial costs for your construction project.

worker running ground penetrating radar rig
Our analyst performing underground utility locating services

When you started your home project, you didn’t imagine that you would need our private underground utility locating services. To ensure that you don’t hit any utility lines, it is important to scan the area first. Damaging utility lines can result in loss of that particular utility. It can also cause injuries for you or the workers hired to do the cutting, trenching, or digging.

Homeowners need private utility locating where 811’s utility locating services don’t apply.

For home owners, utility locating can be a first and only experience. This means that it can be hard to know exactly how to proceed. The first step would be to contact 811‘s Call Before You Dig service, the nationwide public utility locating service. They can locate all public utility lines, from the street to the meter only. If they can’t locate what you need, that’s when we, a private utility locator, come in.

Other reasons for needing private utility location include:

  • Already hit a utility. 811 is a public utility locator. They can locate all utilities from the street to the meter. Any utilities in your private property would need to be located by a private utility locator.
  • Previous scan attempt was unsuccessful. This scenario goes hand in hand with the reason previously mentioned. Sometimes our clients do scan. However, the company they selected didn’t provide accurate markings and the client struck a utility as a result. Our analysts complete extensive utility locating training. They are trained to properly mark your site, provide written reports, and to provide you with the best service.
  • Home improvements. It is always important to locate all utilities before doing any projects that require digging or excavating. This includes, but is not limited to: landscaping, fencing, pool installation, installing a mailbox, deck installation, among others.
  • Water leaks. A lot of our clients suspect that they are dealing with a water leak. While we can’t locate the water leak itself, we can help you locate the water line and look for signals of wet soil that may indicate the location of the leak.

What should you expect when you call a private utility location service?

When you call Penhall Technologies or request to quote, it is best to be prepared with essential information regarding the project. This will allow us to provide the best service and accurate pricing. It is important to know the measurements of the area, the type of surface (dirt, asphalt, concrete), and the location (indoors or outdoors). If possible, provide the utilities we may be looking for (water, gas, electrical, sewer) and how many utilities may be running through the area. We will also ask how many locations you need scanned, and what is the private line locating in preparation for.

North Carolina GPR project
Example of utility markings at a home

Once the analyst arrives at your home, they will be up to date with the needs and specifications of your project. They will bring two types of equipment to offer you the most accurate reading. A benefit of choosing Penhall Technologies as your private utility locator is that we carry various types of equipment. This is in case one method is not enough to find underground lines. In rare cases, the reading can be inconclusive and show highly congested results.

After the analyst completes the scan, he/she will mark the approximate utility locations with varying colors of spray paint, flags, or both to highlight that location.

GSSI
Equipment screen showing utility locating data

Before the analyst marks the utilities, the display screen of the equipment won’t mean much to the common eye. Our expert analysts will be able to identify lines and to differentiate between them based on the data and on physical cues, such as a meter. Now with the analyst’s markings and field report, you can make an informed decision of where to cut, trench, or dig. By deciding to scan first, you will safeguard that your home project is completed safely.

GPR equipment

At Penhall Technologies, our analysts use several types of equipment for optimum accuracy for our underground utility locating services.  The following are a couple of the tools that an analyst may use on any given jobsite.

 

RD 7000 Series – Electromagnetic Detection

GPR scanner The RD 7000+ Pipe and Utility Locator is the backbone of utility locating services.  It can transmit multiple frequencies, has several power modes, and possesses both passive and active systems.  This makes the RD system the most appropriate tool to start locating underground utilities.

Simply put, the RD system works by sending a signal or electromagnetic frequency through the transmitter to the metal pipe, valve, or tracer wire. Then, the system uses the receiver to trace that signal down the length of the pipe or wire.How Electromagnetic Detection Works

There are several ways to obtain a signal from a line.  The two most common ways are to connect directly to the wire within the line, or to connect the wire or meter of the line to surround it with the signal.  These are the ideal approaches to ensure that we are attaching to the correct line when there are several in the area.

 

GSSI Cart with 400MHz Antenna – Ground Penetrating Radar

Utility Locating Device with GPR technoloy Unlike traditional technologies such as electromagnetic detection, GPR can detect plastic, concrete, and metal pipes. This makes it an ideal system to locate underground utilities of any kind and more. This is a great partner to our electromagnetic systems to ensure that we are covering all bases in our utility locating services.

GPR technology works by sending a flash of energy into a surface, such as concrete or ground soil, via a special antenna.  Each unit is equipped with both an antenna and a receiver, as well as a computer system. The computer, also known as the brain unit, can register any reflected signal into an image. This is done by measuring the time and strength it takes for the signal to be transmitted and returned.  These reflections are produced by several objects, such as conduit or pipes.

 

How GPR Helps with Underground Utility Locating

The GSSI utility cart with the 400 MHz antenna can locate utilities to a maximum depth of about 9 feet.  The GPR penetration and resolution of images depends on soil conditions.  To learn more about the factors that affect GPR findings, read here.

Despite the limitations, GPR is often the best way to detect abandoned lines, utilities with no surface valves, PVC, clay pipe, or similar non-metallic utilities.  It is also a good way to determine the approximate depth of the utilities.

Overall, at Penhall Technologies, we stay up to date with the latest and greatest technologies to better serve our customers. Our analysts are not only equipped with top of the line equipment, but have the experience and training necessary to interpret the data methodically and efficiently.

 

For further questions or to receive a quote:

Call or email us at:

844-211-5300

gpr@penhall.com

Or visit our website:

https://www.penhall.com/utility-locating/

At Penhall, safety is our #1 priority. So we didn’t hesitate to help when a general contractor called us to help out with an investigation of a potentially hazardous project. He suspected of safety issues in the construction of a high rise hotel in the booming city of Austin, TX.

Penhall assisted with locating structural reinforcement in 49 poured-in-place columns on the first floor of the building, which would go up to 30 stories.  The goal of this project was to locate the placement of the vertical pieces of rebar along with the horizontal bands. If columns are not properly poured and installed, it can be detrimental to the integrity of the building as a whole.

gpr identifies improper rebar spacing in concrete columns
Austin GPR Analysts worked diligently to scan and mark the columns to verify the reinforcements.  The results, as you can see in the image sequence above, were very telling.  48 of the 49 columns had improper spacing of the rebar. In other words, they lacked the structural integrity to withstand the weight of a multilevel building.

Following the analysts’ findings, the general contractors made the decision to fix all 48 columns. This allowed the general contractor to resume the project and to complete it safely.  Penhall walked away from this project knowing that our work minimized the threat of a potentially hazardous situation.

For further questions or to receive a quote:

Call or email us at:

844-211-5300

gpr@penhall.com

Or visit our website:

https://www.penhall.com/concrete-scanning/