How To Install In-Ground Bollards
Bollards are Everywhere
Look around town and you will see there are bollards all over the place. Yet, the average person doesn’t even know what the word “bollard” means. I explain them as, “They are the steel pipes in parking lots that you don’t want to hit with your car!” And they say, “Ahhh, yeah, I know what you mean!”
Being that bollards are seemingly everywhere, there exists a lot of opportunities in any city or town for the installation and maintenance of bollards. Just about any construction company is capable of installing bollards, but installing them correctly without cutting corners is a way to establish your company as the ones to go to.
Of course, there are many types of bollards for various applications and many ways to install them. Here, we layout the steps we take when we are installing common in-ground bollards.
General Planning
In many cases, an engineer has drawn up the specifications for the project. In other cases, the customer just tells you what they want and/or asks your advice. Be sure you’ve thought through the project and how it will affect vehicle traffic flow, pedestrian movement and if it has proper clearances for crowds, ADA, forklifts, pallet jacks, carts etc. But this is beyond the scope of this article.
Safety on the Jobsite
The safety of you, your workers and others is critical and you should be conciencious of all potential hazards. Use cones, barriers and caution tape to divert people and cars from entering construction area. Always cover holes when unattended. Use steel plate if vehicles may drive over holes. For foot traffic, use 3/4″ plywood and sandbag it and put up cones/tape to divert people away.
Definitely, never leave open holes uncovered overnight or unattended.
Finally, it goes without saying that heavy machinery should be operated by qualified, experienced individuals only.
Insurance
As a contractor or subcontractor, you should certainly have liability insurance with adequate coverage. Most commercial customers will request a Certificate of Insurance (COI) from you that shows your coverage amounts.
Busy Job Site
The picture above shows a worksite in a parking lot for a liquor store that is open and is quite busy. Cones and tape are used with signage to route customers around work area. An “accordion” style plywood wall stands between the bollards and business entrance, keeping customers out of work area while protecting them from potential flying debris.
Bollard Pipe Diameter
Most of the time, we are installing 6″ bollards. These are the most common bollard size. 4″ shouldn’t be used to stop a car, but may help deter vehicles and protect building corners or machinery. 5″ SCH80 (thicker walled) is similar in performance to 6″ SCH40 and is used sometimes for budgetary reasons. Rarely, 8″ pipes are used where greater security is desired, around building entrances for instance.
Bollard Pipe Wall Thickness
For standard common bollards, Schedule 40 (SCH40) pipe is used. Some customers opt for the heavier walled SCH80 for greater security.
-> Browse around our Steel Pipe to see SCH40 and SCH80 differences.
-> Get a Quote on Bollard Pipe
Bollard Foundation Diameter
Typically, a bollard foundation should have 3 times the diameter of the pipe. For 4″ pipe use a 12″ auger bit. For 6″ pipe use an 18″ auger bit. And so on.
Foundation Depth and Bollard Height
The deeper the sturdier. Our in-ground bollards are usually 36″ to 48″ deep. 48″ deep will give you more stopping power in the event a car hits the bollard. 36″ may be adequate. Mostly this has to do with budget. For visibility in a parking lot, we suggest going 48″ high. So, in an ideal world, you’d install 8′ (96″) bollards so they are 48″ high and 48″ deep. Don’t put a 36″ high bollard in a parking lot… they can be hard to see over the hood, especially with how high pickup trucks are these days.
84″ is Stock Bollard Pipe Length
Since bollards are cut from 21′ and 42′ pipes, steel yards tend to stock 7′ (84″) bollards, since you can get 3 out of a 21′ pipe with no waste. For budget reasons, most customers will opt for these.
If visibility is crucial and often is, you’d put these 36″ in the ground. If you definitely need maximum vehicle stopping capability, then you’ll want to go 48″ deep which leaves only 36″ above ground. 36″ above ground is only advised above a curb and not in direct vehicle traffic.
Going for the 96″ Bollard Pipe
If you need both a deep foundation and high visibility, you should probably use 96″ or greater bollard pipe.
- Bollard Pipes -> Get a Quote
- Sign Posts – If you are embedding sign posts into pipe.
- Use 1 1/2″ or 2″ Galvanized Perforated Square Steel Tubing for sign posts.
- 5/16″ Threaded Rod, washers and nuts – explained below.
- Signs
- 5/16″ Hardware for signs – bolts, nuts, washers, nylon washers for use against sign faces.
- Concrete – We always use a ready-mix concrete truck (unless it’s Sunday).
- 3500 PSI or higher with some aggregate
- full air (air entrained) is suggested
- up to 2% chloride accelerator if it’s cold out.
- Asphalt – If customer doesn’t want a concrete square around the bollards in an asphalt lot, you’ll leave foundation shy and patch asphalt. Find an asphalt company unless you happen to do asphalt.
- Gravel – Is helpful to line hole bottoms to adjust pipe height – especially when aligning many. 50 lb gravel bags work well for this.
- White Spray Paint for Marking
- Ground Protection: Ram Board, Cardboard, Tarps or Plywood – For keeping existing concrete/asphalt clean while doing concrete work and painting.
- Paint: Enamel, Primer and Solvents
- Lacquer Thinner or Acetone – Clean Pipe if Bare Steel.
- Mineral Spirits – Cleaning paint brush etc.
- Spray Automotive or Metal Primer if not already primed. Often Red-Oxide.
- Paint – use Rustoleum Oil with a roller. Usually Safety Yellow.
- DO NOT PAINT GALVANIZED – Paint won’t stick worth a dang.
- Rags
- Gloves: Nitrile Gloves – nice for shaping concrete dome on bollard and painting.
- Garbage Bags or Demo Bags
- Bollard Covers – These pay for themselves after year or two because you won’t have to paint and repaint. Steel Bollards do rust, especially at the bottom where they meet the ground.
- Machine: Skid Steer, Track Loader and/or Excavator
- Machine Accessories:
- Bucket – for debris removal
- Forks – to unload pipe from truck and move around.
- Auger Head with Bit(s)
- Breaker – if you have one, otherwise use a jackhammer.
- Concrete Saw – Handheld or Walk-Behind
- Garden Hose – if wet sawing and also useful for clean up.
- Water Tank with hose spigot – at least 50 gal. If no water spigot source is available.
- Debris Removal: Dump truck, dump trailer or dumpster – for asphalt, concrete and dirt debris.
- Long Handled Tools: Shovels, Post hole digger, brooms
- 2x4s, 2x6s, 2x8s – for shoring up bollards
- Stakes – for shoring up bollards – wood or Steel Stakes aka Rebar Pins
- Small Sledge Hammer – for driving stakes.
- Masonry Tools – float, edger, brush, 5 gal bucket
- Funnel and Scoop for filling bollard pipes.
- Concrete Vibrator – if specified
- Hole Covering: Heavy steel road plate or plywood for covering open holes – use heavy steel road crossing plate (may be rented) if vehicles might drive over hole(s), or simply don’t leave open holes without pipe in them. Sandbagged and coned off, 3/4″ plywood will keep people from falling in a hole.
- Traffic Safety: Traffic Barrels, pylons, cones, signs and caution tape
- Measuring/Marking: Tape measures, Level(s), string line, chalk line, crayon, markers
- Duct Tape – of course.
- Impact Driver with T-25 Torx bit – for shoring up bollards with stakes and 2x4s
- T-25 Torx screws – 2″ – 3″ for shoring work
- Angle Grinder with flap disks and cutoff disks
- Metal Band Saw – Portable preferred – for cutting of sign posts.
- Generator – If no power is present and you have corded tools.
- Extension Cords as needed.
- Common Tools: utility knife, pliers, channel locks, wrenches, screwdrivers etc.
- Garbage Bags or Demo Bags
Before opening a ticket for Utility Locating, you need to mark where you will be excavating. You may as well do a good job marking now so the layout is completed for tasks that will soon follow.
Mark with White Spray Paint
In Minnesota, we are asked to use white for excavation markings. Your state may or may not be the same. When the snow is flying, sometimes we have to be creative and use another color so it can be seen. Avoid common utility marking colors like orange, red and blue. There are exceptions if the markings are obvious.
Marking on Asphalt and Concrete
Since you will be cutting and removing material, you will save time by marking your cut lines now. We like to use a square stencil. For a 6″ bollard, we use an 18″ auger bit. So we cut a 22″ x 22″ square out of a 3′ x 3′ larger square of masonite hardboard or cardboard (any flat stock will work).
Line of Bollards
If there are a line of bollards, we’ll pull a string or chalk line that will be one side of the squares. Then we measure out bollards on that line and place the stencil along the line for each bollard and spray paint the edges. This makes for straight cutting lines.
Core Drilling
A note about Core Drilling: If instead you are core-drilling concrete, make the appropriate size square or circle stencil that will help the cutter operator center the core cutter.
Marking on Landscape
Simply put an “X” marks the spot for each bollard and a circle approximately the diameter of your future hole.
Take Pictures
If your state has an online utility locate website, you may be able to upload the pics which helps a ton. Otherwise, they may come in handy for describing markings, or you may end up sending pic(s) to one of the locators if they call you with questions.
Either way, you will be either mapping out excavations on a map online, or describing the excavation locations online or on the phone.
Open a Utility Locate Ticket
Usually, the excavator who is digging must be the one to open a public Utility Locate Ticket.
Every state has their own utility locate service. If you do not know yours, you can call 811 to find it. Or you can go to their website here: www.call811.com
Those in Canada can also call 811 or go to the 811 website.
Wait to Dig
Usually, there is a 72 hour wait until all locating is done. Some utilities know there is nothing on property so they won’t visit. Some utilities will mark “clear, no conflict” on the ground. Most or all will mark lines that are close to your digging locations. Often, if there is a conflict or they are unsure, they will call you. You will be notified via phone call or email about the status of the locate at the end. Then you will know if there are no conflicts.
Private Lines Underground
IMPORTANT!: Often times there exists private electrical, water, propane, low voltage etc. lines underground that the utility locate ticket WILL NOT LOCATE. The property owner MUST locate these themselves. They may have to contact those involved in the construction of the building, their electrician, their water sprinkler company (the list goes on) in order to find out if there are any conflicts with your digging locations.
If there are Conflicts
If there are conflicts, either public or private, you will have to modify some digging locations or your entire project. Be safe, not sorry.
Cutting Asphalt and Concrete with a Flatsaw
Asphalt is typically 4-6 inches thick, and concrete can be 4, 6, 8 or more inches thick. In any case, your going to be cutting with a concrete saw, handheld or walk behind. The walk behind saw may have water fed to it to keep the dust down and the blade cooler.
There are many types of blades out there to be aware of. Some are all purpose, and some cut one material better than the other.
The walk behind style is a lot easier on the back, but the handheld is quicker if you don’t have too much to cut. The handheld also enables you to get into tighter spaces.
Core Drilling Concrete
Core drilling is done with a large drill on a sort of cart and cuts a hole in the concrete. Core drilling takes longer, requires more specialty equipment and is more expensive. It is most often done where appearance is more important. It’s not typical to be done in asphalt.
When the customer wants core drilling, we subcontract that out. For us, the request is rare enough that it doesn’t pay to own all the equipment.
Cut Squares in Asphalt – note the Plywood Accordion Wall
Ye Olde Target Portocut III
Remove Asphalt and Concrete
Use a jackhammer or breaker attachment to break up concrete or asphalt enough to remove it. If you find concrete was thicker than anticipated, this can take longer than expected, and you’ll wish you had a bobcat with a breaker.
Keep Debris Types Separate
A lot of disposal places won’t take mixed up dirt, asphalt and concrete. Instead of learning the hard way, keep them all separate. Often, you can keep them pretty separated in a dump trailer, enough to unload the asphalt and/or concrete by hand first and then dump the dirt.
Almost always, and whenever possible, we use a bobcat with an auger head and bit to dig holes.
Mark your depth on a 2×4 and have a second person assist the bobcat operator. When near the bottom of the hole, use the 2×4 to judge depth.
Line the Bottom with Gravel or Debris
Especially when installing a line of bollards, you’ll want them even in height. In this case, it can be helpful to dig a couple inches too deep, then fill the bottom with a couple inches of gravel. This keeps the bollard from sinking too deep and allows you to adjust the height by spinning the bollard into the gravel to drop it, and lifting it back out to raise it. If you need to raise a bollard even more, throw some larger rocks or broken concrete/asphalt down and position it with a 2×4, lifting the bollard on top of it.
Hand Digging Bollard Holes
Hand digging is not fun, but sometimes it is necessary. If you have a situation where you think there may be some private utility lines (e.g. sprinkler system lines), you may need to be more careful digging around these lines, so an auger may be too much. IMPORTANT: If you suspect public utility lines, you shouldn’t be digging at all unless you’ve discussed this with the utility locator and they’ve given you direction.
Fun tip: If you don’t have too many bollards (or if youd do…haha), and you have the energy or the labor, you can surely dig as many bollard holes by hand as you want!
Fun
Funner
Standalone Bollards
Bollards that standalone and don’t need careful alignment can be leveled for plumb on the fly. Just make sure it’s seated at the correct depth and the pipe is centered a the hole bottom. Lean the pipe on the edge of the hole until you are pouring concrete.
Use 2x4s to Shore Up Bollard Pipes
On landscape, you can stake a couple 2x4s next to pipe to plumb it square to the 2x4s and stake them and screw the 2x4s to the stakes. Next, plumb it the other way and screw chunks of wood to the 2x4s. See Pic.
On asphalt or concrete, you can use chunks of 2x material to shore up pipe against cut-away asphalt/concrete edge. It helps to have a bunch of different length scraps. Just wedge them in there till bollard pipe is relatively stable.
Set the End Bollards First
For a line of bollards, set the end bollards first, then draw a line between them to set the in-between bollards. This will give you a consistent height and alignment. Since these end bollards are critical, make sure they are shored up sturdy. You can even put a bag or two of quickset concrete at the bottom.
Keeping Signs Straight
If you are embedding sign posts into bollards, keeping signs straight and plumb can be tricky. Here is a method that works well.
Use Xs to Center Sign Posts
As long as your bollards are plumb, your sign posts will be plumb with this method.
- Use your choice size of galvanized perforated steel tubing (e.g. 1 1/2″, 2″).
- Determine how high you want these to extend above the bollard for the sign(s) (call this length A). Unless you are confident you know the exact sign sizes and target height, you may want to keep the posts longer, then cut them off afterwards. But at worst, if you’re post ends up too short, sleeve it inside and add more tubing above.
- Add 12″-24″ to that length (call this length B). This is how far down the posts will be embedded.
- Cut your post length L = A + B.
- Cut 5/16″ threaded rod the size of the inner diameter (ID) of pipe. Use a grinder with flap disk to fashion the length until it fits fairly snugly.
- Make a threaded rod “X” at the bottom of the post. Center rods and screw on nuts with washers.
- Make a threaded rod “X” a hole or two below what would be length B from the bottom. Center rods and screw on nuts with washers.
- Above the top “X”, mark with tape where the top of the concrete dome will be.
- When filling the bollard with concrete almost full, you will stick this contraption in, drop it down to where the top threaded rod is just under the rim of the bollard pipe.
- Make sure sign post is oriented correctly so sign will be facing correct direction.
- As you fashion concrete dome to the post and as concrete begins setting, be sure the post hasn’t sunken and remains square and plumb.
Threaded Rod X
In the pic, these posts actually extended to the bottom of the bollard foundation, so the bottom X was set up higher. We found this method to be unnecessarily expensive because sign posts had to be 13′ to 15′ long. And it was a PITA: you had to fill concrete around the post the whole time without a funnel, rather than just near the top, which was difficult. Having learned, now we just have the post extend 12″ to 24″ into the bollard and leave it out until we have mostly filled the pipe.
Estimating Concrete Yardage
You can use our Concrete Yardage Estimator to figure out how much concrete you need. Always get extra, because it’s expensive to get an additional truck. Do estimates for both (1) the foundation as if the pipe wasn’t there and (2) the pipe from the foundation up. Then add these together. Finally, multiply this by the number of bollards you’re installing.
Order Ready-Mix Concrete
Usually, you want to order the truck a day or two in advance. Larger town and cities probably have Saturday Service except in off-season in the cold north.
Concrete Specifications
For bollards, you may want to use a higher PSI like 3500 or greater. You’ll want some aggregate in the mix.
Air in the Concrete
It is advisable to do “full air” (air entrainment) if you are finishing the concrete at grade level as opposed to topping it with asphalt or dirt. The primary purpose of air entrainment is to increase the durability of the hardened concrete, especially in climates subject to freeze-thaw; the secondary purpose is to increase workability of the concrete while in a plastic state in concrete.
Concrete Slump
You’ll want a slump of about 4″. With slump, the higher the number, the wetter the concrete. You can also order a 3″ slump and have them add water if it seems to dry, but you can’t take water out obviously. Some ready-mix companies are more arbitrary, and the concrete shows up much wetter than expected. If that happens, you can let it sit for 30 mins to an hour before doing final finishing.
Chloride Accelerator
You can use some accelerator if it’s cold out – 1% to 2% max for chloride.
Ask your ready-mix concrete company what they suggest if you are unsure.
Pouring Concrete
Keeping Mess to a Minimum
If you are working over existing asphalt or concrete, you probably don’t want concrete splattered around. Some of it is unavoidable. At least right around bollards, it’s nice to have something on the ground like Ram Board, plywood, masonite, cardboard or tarps. Generally, you can resuse this stuff down the line or on the next job, but you don’t want to blow too much money here.
Also, be careful if there are cars parked close by. Especially when filling bollard pipe, the concrete can really splash up high in the air sometimes.
Pour Slow at First
The truck operator will back up to a bollard and get the chute on and start pouring the concrete. Start with the foundation, and do the pipe only after you have at least half the hole filled. Make sure to go slow at first filling the foundation hole because the concrete can shift the bottom of the pipe and it will be virtually impossible to shift back. While it’s filling, you can distribute concrete around the pipe with a shovel or 2×4.
Filling the Pipe
It helps to use a funnel and a big scoop, like a feed scoop. A funnel is easily made from a traffic cone by cutting off the top. Have the operator fill a wheelbarrow about 1/2 way to work out of. Alternatively, if you aren’t worried about mess, have the chute pour straight into the top of the pipe. You just have to wipe down the pipe then.
Vibrating Concrete
Vibrating concrete is always a good idea as it makes it stronger and reduces voids, especially on the surface. It will help concrete fill out inside the pipe too. Even so, it isn’t typically done in bollard installation, but may be specified by engineers or project managers.
Finishing Concrete
Doming the Concrete
The simplest way is to just wear some gloves and form the dome by hand. If you want to get fancy, you can cut an old basketball in half and use that to form the dome. If it’s too wet, just wait.
Finishing at Grade
Be sure you’ve got the dome pretty much under control so you don’t screw up your finishing work below at grade.
Begin floating the concrete at the grade level and add or remove some as needed. Get it floated out nice and smooth. If specified or desired, you can slope the concrete a bit so it’s higher at the pipe and encourages water run-off. Now use an edger to put a nice consistent rounded finish edge around the square. After floating and edging, let it sit for 15 minutes or so, then brush it to give it a nice even texture. Go around the pipe first, then pick a direction and try to make the brushing straight.
Pipe Cleanup
Wipe down bollards with rags to remove concrete splatters and drips. Don’t worry about the thin layer of concrete film at this time.
Never Leave Bollards Bare Steel
Even if you are covering with a Bollard Cover, you’ll want to at least have primed bollards, but we often paint them as if they were being left uncovered. This will increase the longevity of the pipe. Bare steel will rust, no doubt.
Painting Preparation
If the bollards are not smooth, or have concrete spatter or mild surface rust, it is good to run a sanding sponge over them first. Then, wipe down bollards quickly with a solvent like lacquer thinner or acetone. You can do this even if they are pre-primed. This will remove the dust and oils from the pipe.
Priming and Primer Touch Up
If you need to prime bare steel or touch up pre-primed bollards, use an automotive primer spray. Most commonly, we use the red-oxide primer spray.
Painting Bollards
The best all around performing coating I believe is the rustoleum oil out of the can. Most common is the Safety Yellow color. Use a 4 inch roller and a small brush to cut-in around the bottom. Do 2 coats if you can still see through and aren’t getting full coverage. If you are going to cover the bollards, you might find a good spray enamel works just fine. Do lighter coats to avoid dripping.
Installing Bollard Covers
If you painted bollards, of course, wait til they are dry. For enamel, this could take a day.
See our page on How to Install Bollard Covers for the specifics.
Never Paint Galvanized Bollards
Paint does not stick to Galvanized Steel for very long. A quick solution here however, is to install bollard covers.
For comments on this article, please email sales@stpaulsign.com.
