A Brief Introduction to Concrete Sawing

Are you interested in learning about successful concrete sawing techniques? Let’s start by looking at the two basic saw types ideal for concrete sawing:

  • Handheld saws
  • Walk behind saws

Difference between Handheld and Walk Behind Saws

Handheld saws as the name implies are handheld tools, which are relatively easy to use. A good handheld saw should be lightweight, portable and flexible.

You can use them for cutting wall openings or for small surface jobs, such as, access to holes, or curbing. Proper access to holes allows you to place posts in existing slabs.

Walk behind saws, on the other hand, are much larger than handheld saws. To use them, you have to walk with them. With this kind of saw, you have to remain standing throughout the sawing process.

Walk behind saws also pack more horsepower. Their cutting rate is also considerably faster than the handheld varieties.

The size, weight and power of walk behind saws combine to allow greater force during the cutting process.

However, due to their size, walk behind saws require more room for maneuvering. For cutting of short runs however, handheld saws are a better option. The single side blade mounting in walk behind saws allows close wall cuts.

Gasoline powered concrete saws emit harmful fumes, making them unsuitable for confined spaces such as basements. In cases where high windows are present in the project space, even the presence of a fan will not be of any help.

However, in garage areas, and factories with ventilation at floor level, the use of fans seems a practical choice for controlling exhaust fumes.

With electric hand held saws, however, the need for proper exhaust isn’t so critical because no fumes are emitted.

Due to being electric powered, these saws only lend themselves to dry cutting. This, however, poses hazards related to dust that emanate from the cutting process. You will not be able to use it in the basement.

The best saw for enclosed spaces is however, the pneumatic saw. These utilize compressed air for operation and can be of walk behind or handheld varieties.

In addition, these also offer flexibility of use for dry or wet cutting, leading to better dust control. Rental costs of pneumatic saws are high because of the need for a large portable air compressor.

The unit itself sits outdoors with a big hose reaching the places you require for proper cutting. Chain saws are your best choice when you want to make a small cut into a wall.

Pneumatic powered chain saws, equipped with diamond chain for concrete cutting are also available. These are so powerful they’re able to cut through a 15-inch wall effortlessly in one pass.

Saw Blades

Concrete cutting involves grinding using blades designed for the purpose. Eventually, the blade will wear out during the grinding process.

One of the most cost efficient options for such projects is of course the aggressive blades and these are ideal for short jobs. One can use it until it completely wears down.

Diamond blades have the ability to resist wear and tear, making them a popular choice for cutting and grinding jobs. These remain laser welded to segments with steel hub.

As they wear with use, they will drop off within the cut, allowing a new row to emerge to take its place.

Compared to the abrasive variety of blades the diamond ones are quite expensive and for good reasons too. They signify enhanced durability, resistibility, and faster cutting besides a host of other benefits, which makes the extra expenses easier to bear.

The narrow swath related to these blades signifies a narrower cut with less dust emanating from the process.

Hints for Optimizing Cutting Results

When cutting concrete, how deep you want to go is an extremely important consideration. In most cases, these cuts are mostly 2 to 4 inches deep.

As a result, the cement considerably weakens; leaving the smooth joints on surface visible. After this, you can break off the concrete pieces easily using an air hammer or an electrical breaker.

Asphalt Cutting

It is important to remember that asphalt saws are different from those intended for cutting concrete. Asphalt saw blades are usually more aggressive yet softer than concrete blades and yield to both dry and wet cutting methods.

Aggressive blades are the best for short jobs. General blades work well with asphalt over concrete, but you require extra care when cutting asphalt over gravel.

How to Control Noise and Dust When Cutting Concrete

Anyone who’s ever tried cutting concrete will tell you that dust and noise are two of the biggest deterrents to the job.

Concrete dust containing silica and a variety of other hazardous materials can lead to severe breathing issues, and the high noise levels can damage hearing.

Fortunately, there are effective ways to control noise and dust associated with concrete cutting.

So what methods work best for controlling noise and dust? Dry cutting as everyone knows gives rise to large amounts of dust laden with silica, which is the single most health-damaging component of concrete dust. These abrasive tiny particles,

  • Damage the lungs of a person
  • Reduce the capacity to breath
  • Leads to chronic breathing trouble

Continuous exposure to silica may lead to lung cancer, tuberculosis, and COPD.

Dust and noise associated with concrete cutting at construction sites are a serious health hazard leading to respiratory illness and hearing loss to the workers.

One of the crucial engineering controls for minimizing the damage and developing a healthy environment for workers is the application of the wet method of cutting concrete. Studies indicate that the use of water in relation to concrete cutting can reduce the concentration of hazardous dust to a staggering 85%.

“The wetter the better” seems to be the motto when it comes to concrete cutting. This is an evidence-based finding, so it is completely dependable.

According to a recent research, respirable geometric mean concentration of dust through dry cutting is approximately 14.396 mg/cubic meter, which is 10 times more than wet cutting projects.
The use of water hose during concrete cutting reduces the amount of silica dust to just under 1.1 mg/cubic meter. Spray control on the other hand, allows only 1.2 mg/cubic meter of silica dust to escape to air.

Studies undertaken in relation to various tools for concrete cutting have thrown up startling results, but all seem to indicate towards one thing.

Based on OSHA regulations, one should never use concrete gas powered saws for dry cutting.
The only exception can be made in cases where the construction firm is ready to take the onus for a sampling to ensure that dust exposure never increases above the allowed limits.

However, by knowing the exposure levels related to various concrete cutting projects as well as in relation to two different types of equipment used, it is possible to take the necessary precautions.
Through the use of the right respirators, it is possible to keep dust and noise exposure levels to a minimum. Regularly using water controls with concrete gas powered saws is an effective and proven way to reduce respirable dust levels significantly.

Aside from ensuring the safety of the workers, firms also need to ensure the well-being of the onlookers and other people present on-site.

In addition to using the right methods for concrete cutting, preferably the wet one, it is important to use the right precautions to ensure complete protection from dust and high decibels.

Here are some protective measures approved by OSHA for ensuring the best results related to concrete cutting projects without compromising the workers health:

A. Use of respirators: Respirators offer the best protection against dust laden with hazardous silica. Proper training related to this protective equipment is necessary to ensure optimal benefits. It is the job of the project manager to ensure effective training.

B. Use of safety glasses: Use of proper safety glasses is extremely necessary to keep the eyes protected throughout the cutting process.

C. Good quality headgear: When you are protecting all the parts of your body during concrete cutting, it is important to consider a good quality headgear too. A hard hat forms a barrier against falling objects, so its importance should never be underestimated.

D. Proper hearing protection: Proper hearing protection, such as earmuffs and earplugs are another must have when it comes to concrete cutting sites. However, it is important to replace them on a regular basis to avoid chances of getting ear infection. Also, proper training in this regard is necessary.

E. Use of proper foot protection: The wearing of proper footgear is extremely necessary for protection against twisted ankles or abrasions of any kind. Over-the-ankle leather solid boots are a good choice.

Studies indicate that the use of wet cutting methods for concrete is the best way to keep workers safe from the hazardous dust.

However, for ensuring better control of noise, it is important to use high-quality equipment and maintain them in good order. This, along with the use of the right protection is a surefire way to maintain optimal construction place conditions.