When it comes to the job site, few tasks call for raw, unbridled power quite like concrete demolition.
To take on the tough task of breaking up aged concrete, contractors and extreme DIYer's are faced with a dizzying array of choices, all of which claim to be the best choice.
From handheld rotary hammers to mounted breaker hammers, there are a bewildering number of tools that all drive metal against concrete in a variety of ways. Where the jack hammer shines, though, is in their simplicity and versatility.
There are no rotation modes or drill bits to mess around with, all you get with the jackhammer is a range of solid hammer-driven chisels that efficiently chip away and break up concrete and tile.
How Jack Hammers Work
Jack hammers are also often referred to as pneumatic drills or demolition hammers, depending on the type of the power tool. The classic jack hammer is the one you might be familiar with from roadwork scenes – the larger in-line tools powered by compressed air.
There are also smaller demo hammers under 30 pounds that are used in interior work to chip away at walls to open up spaces for conduits and other things, as well.
Most jack hammers use a spinning gear that drives a piston inside its cylinder. The faster the gear rotates, the more power the piston receives as it flies down in the cylinder, until it slams down into a cushion of air at the end of the cylinder.
The pressure drives another piston that rams into the business end of the tool, resulting in the trademark blast of air that gets sent out of the vents of the tool with each strike.
Some jack hammers skip the air pocket entirely, with models that feature direct metal-to-metal strike designs.
Choosing the Right Type of Jack Hammer for The Job...
When it comes to the choice of the right jack hammer for the job, the decision usually comes down to size. Size and power are paramount when it comes to demolition tasks, and you need to make sure that your tool will deliver.
On the other hand, you would appreciate a lighter demo hammer for horizontal applications like chipping out grooves at waist height or higher.
It’s not uncommon to have different types of jack hammers doing different roles in the same jobsite.
Jack hammers are often classified in the industry by grouping them into three basic weight categories.
Lighter models under 30 pounds are often referred to as chipping hammers or demo hammers, while heavy duty models start at around 35 pounds and are usually called breaker hammers or pavement breakers.
Then there are the construction-grade models that weigh 60 pounds and up.
When it comes to handheld jack hammers or demo hammers, you also have a choice between electrical pneumatic types, the air-driven pneumatic type and the industrial-grade hydraulic hammers.
Light Jack Hammers / Demolition Hammers
Light jack hammer models comprise those in the 20 to 30 pound class and include chipping hammers, and these jack hammers are generally considered to be equivalent to rotary drills in hammer mode in terms of power.
In general, lighter jack hammers are almost always the electric pneumatic type.
Many light jack hammers come in the pistol grip L-shaped form factor, making them especially suited for horizontal work. Light jack hammers under 25 pounds shine for wall and ceiling work, and are useful for renovation jobs and indoor demolition work.
They are useful for cleaning up edges left by rougher demolition work, and in chipping out concrete around pipes, conduits, chases and finishes.
Very small demolition hammers are also called chipping hammers, and they can be really compact indeed.
Some corded chipping hammers weigh less than 7 pounds and are more practical for small, precise jobs around light masonry material. The air hammer would also be a great substitute for some of the lighter work.
Medium Jack Hammers
Jack hammer models that run about 35 to 40 pounds fill in the gap between light jack hammers and massive pavement breakers.
At this weight range, the jack hammer models begin to feature a hybrid inline and pistol grip design which lets you use them horizontally or vertically.
These jack hammers are versatile tools that can do the job of breaking up heavy concrete as well as a bit of detailed chipping work, and it reflects in the wide array of chisels and shanks available for them.
They are built for heavy-duty applications, but they can also do chiseling work with the right flat or scraping chisel attachments.
Many of these medium-sized heavy duty jack hammers are of the electric pneumatic variety, and they have their place in roadwork construction, too.
Contractors can only run so many large breakers off their air compressors, so heavy duty electrics fill in the gap by floating around the jobsite to take care of smaller tasks and clean up rough edges.
Heavy Jack Hammers
These jack hammers rely on their weight for vertical applications, and starting at 60 pounds, these tools are hefty indeed. This class of jack hammers is also known as pavement breakers, due to the usual job that they do on the jobsite.
At this weight range, you begin to see pneumatic jack hammers and portable hydraulic tools.
A pneumatic jack hammer is also known as pneumatic hammer or pneumatic drill, and they use compressed air as their power source – hence the need for a portable air compressor.
Hydraulic jack hammer technology have progressed to the point that you can use one of these in handheld form. Some hydraulic jack hammers are connected by hydraulic hoses to a portable hydraulic compressor or even a worn power pack.
Other types have a small gas or diesel powered engine driving a hydraulic pump mounted on the tool itself.
Mounted Jack Hammers
No guide to jack hammers is complete without a mention of mechanically mounted jack hammers. These huge tools can only be used with excavators or backhoes, and are widely used for heavy duty construction groundwork, roadwork, quarrying and large scale demolition.
Some of the largest hydraulic jack hammers can rival blasting in the amount of rock that they can take out in a day.
Pneumatic Jack Hammers
A pneumatic jack hammer, also known as a pneumatic drill, is the classic form of the jack hammer dating all the way back from when it was first invented in the 1800s.
The basic principle has remained the same throughout the decades – a line of compressed air supplies power to the jack hammer, which drives an internal hammer that strikes the shaft.
The explosive air exhaust of pneumatic jack hammers adds a lot of force to the already dangerously loud noise that the classic pneumatic jack hammer makes. To deal with this hazard, most pneumatic jack hammers now feature a silencer sleeve around the barrel of the tool.
Using a pneumatic jack hammer also exposes the user to excess vibration, which may accumulate to the point that blood circulation in the hands may be affected.
Protective hand gloves can take out some of the discomfort, and manufacturers have begun to offer vibration reduction systems as well.
Hydraulic Jack Hammers
Hydraulic jack hammer systems are usually reserved for mechanical excavators and backhoes for outdoor work, but the size of these machines make them impractical for working inside buildings or when surrounded by built spaces.
The need for hydraulic powered jack hammers have given a rise to portable hydraulic jack hammers, and some of them can be more compact than the usual pneumatic hammer and air compressor combo.
These power packs can be powered by small gas or diesel engines, and most portable hydraulic jack hammers are more efficient and more powerful than a comparable pneumatic model.
Portable hydraulic jack hammers have found a niche as a standard piece of equipment used by emergency teams.
The small 2-stroke engines can make them bulky, but with no compressors, hoses or cables to set up, this is a tool you can take just about anywhere.
Electric Jack Hammers
There are electric jack hammer models for almost all weight class hammers nowadays, starting from compact 6-pound chipper hammers to 60-pound vertical jack hammers.
With no emissions and little in the way of maintenance required, electric jack hammers have become popular with rental outlets.
Many manufacturers have also started adding features to their electric jack hammers that you would normally expect from the more refined consumer power tool models.
Vibration control, auxiliary handles, LED maintenance indicators and dust control are quickly becoming standard in electric jack hammers, along with new tips and better attachment systems.
That said, electric jack hammers still have some way to go when it comes to raw power. Heavier pneumatic jack hammers still outperform the heaviest of electric models for a wide margin.
With your typical compressor-powered jack hammer providing double the impact power compared to your electric.
Features to Look For in Jackhammers
- Noise level control features not only help preserve your hearing, they also ensure that your tool and your jobsite are compliant to noise emission standards as well. Mufflers and silencers go a long way in reducing noise levels.
- Vibration control features help you avoid white finger and carpal tunnel, and they can range from vibration dampening handles to internal shock absorbers.
- Accessible power controls and dials lets you use them easily without having to take your hands off the tool, and sensible layout lets you operate the jack hammer easily even with gloves.
- Boxes and tool cases are especially important to keep you from losing the wide variety of bits and attachments for your jack hammer.
- Insulated plugs lets you run corded electric jack hammers even in less clear weather.
- LED service and power lights alert you to the need to replace electric motor brushes, or cord problems that may damage the motor.
- Soft start and variable speed controls lets you gently start up the demolition hammer for better control and accuracy near pipes, conduits and other breakables.
- Lock-on button controls lets you focus on gripping the tool for extended use.
Comparing Jack Hammers, Chipper Hammers or Demolition Hammers
Ultimately, your choice of jack hammer is often decided by the nature of your demolition job. If you will be doing a lot of wall and ceiling work indoors, a lighter electric demo hammer is the tool for you.
For breaking age-hardened pavement slabs or for breaking up long stretches of asphalt, you will appreciate having the right air jack hammer at your disposal.
When choosing a jack hammer versus the application, it usually comes down to power and weight. When faced with a tough decision, the available features on the tools can make a difference, however.
Weight
Weight is one very important consideration when it comes to jack hammers, so much that these tools are grouped into weight classes that neatly sort them out for the jobs they are best suited for.
Weight is usually cited in terms of pounds, and for handheld models, you have a bewildering range of weights to choose from.
Six pounds is about the minimum for a compact chipper hammer, and it goes up from there to 90 pounds or more for air and gas powered models.
Power and Speed
You need power for demolition jobs, and for jack hammers, the effective power of your tool can depend on several factors – weight, impact energy, beats per minute, and even the balance of the tool.
Impact energy or impact force is usually given in terms of foot-pounds. The higher the figure the more punch the jack hammer can deliver – especially with a lot of weight behind it.
Speed is usually given in beats per minute (BPM), and manufacturers will often cite a “no-load” BPM rating. The higher the rating, the faster the tool will cycle between hits, which can lead to shorter demolition sessions. There is the increased vibration to consider, though.
Manufacturers will also cite motor power or air pressure figures to give you an idea of the potential power of the tool.
For electric jack hammers, this will be in Amps (A) while pneumatics will have their figures in cubic feet per minute (CFM) and pounds per square inch (PSI), all handy information to have when matching them with an air compressor.
Portable gas powered hydraulics have their own mini-engines, with their displacement and power ratings. These are usually given in terms of cubic centimeters (cc) and horsepower (hp)
Bit Holder System
The bit holder system is important if you will be standardizing your tool collection. Most demolition hammers take the SDS shank bit standard developed by Hilti and Bosch, which has since branched out to several types.
Nowadays, SDS Max is the more common adapter for demo hammers, aside from Hilti’s own TE-S system, while hex shanks are still popular for pavement breaker chisels.
Common Types of Jack Hammer Chisels
- Flat Tip Chisels allow you to cut edges and control the direction of your breaks
- Stake Driver Tips lets you drive stakes into concrete for starting break spots
- Spade Tips also lets you add flat edges, and work well in dirt or clay
- Flex Chisel Tips are slightly flexible to let you get under tiles and pavers
- Point Tips are for general-purpose concrete and masonry demolition
- Brushing Tools and Scrabblers are useful for rounding down rough spots on concrete and putting a cleaner finish on a surface before bonding.
