30 Dock Leveler Pit Installation
Today we started excavating and framing 30 dock leveler pits for a warehouse bringing in a new tenant. If you are a commercial property manager, you are no stranger of doing full customization projects for new tenants.
With warehousing and logistic industry roaring, we are constantly installing new and improved dock levelers.
The current project we are taking on is a simple remove, widen, and replace of existing dock levelers into new and bigger dock levelers.
There are two different approaches we are taking for this project because we are also adding dock pits where there once was only flat floor.
The first approach includes reusing the dock pit floor, while the second approach entails much more excavation and installation of a new dock floor.
The beginning of both approaches start with an extensive array of saw cutting, concrete chain saws, and slurry removal.
Laying out the desired cut marks is your first vital step to successfully removing and replacing dock pits. If our marks are too small or off center, it may end up costing over double for saw cutting and removal of the existing concrete.
We always double check the project specifications as well as the measurements we make on the slab before the concrete saws even make it to the job site.
Whatever size of the new dock pit is going to be, we give ourselves a minimum of 8inches around the exterior of the angle irons.
IMPORTANT: You must check to make sure the new corners are square to the outside of the building. If the cut out is off square, you could introduce a number of headaches when looking to install the new concrete and dock levelers.
For this project, the interior dimensions of the dock pit are 7’1” wide and 7’7” long.
Mark for Concrete Cutting
The door openings where the dock pits will be installed are 9’ wide. So first I made a mark at 4’6” off of either of the door openings to find center. From center I made a mark at both sides at 4’3” giving me an 8’6” opening on center.
An 8’6” opening gives me plenty of space to install a 7’1” dock frame with at least 8” of concrete on either side of the pit being tied into the existing slab.
From our outside marks I now needed to find square coming off the face of the building. To do this I used a string line, square, 10 foot straight edge, tape measure, and pencil.
I pulled a string line across the face of the exterior of the building, laid the 10 foot straight edge on the existing concrete touching my exterior marks, then used my square to adjust the 10 foot straight edge perpendicular to the string line.
Once the straight edge was square with the string, I quickly made a mark on the opposite end of the straight edge so I did not lose my square.
Next, I measured 8’6” out from the string line directed inside of the building and made a mark crossing the square mark. Do this on both sides and you will have all four points of your future dock pit.
CHECK SQUARE. Take a tape measure and measure the diagonal dimensions. If the measurements are within a quarter of an inch you are pretty much square for cutting concrete.
If your measurements are not square, start the process over and make adjustments to get square on the cross measurements.
DOUBLE CHECK YOUR WORK and give the okay for the concrete cutters to start working.
Start Saw Cutting
The number one concern with all of our contractors is time and cleanliness. Even if the building is not occupied there are most likely other tradesmen working that cannot be breathing in dust, as well as our own guys.
We use Husqvarna saws to go down as far as necessary to pop out the concrete easily, instead of breaking the concrete out with a machine.
In the past we would cut down 8” and use the skid steer to break out the concrete, but we have found it more efficient and cleaner to do most of the work with the saws.
By cutting down below the bottom of the slab we are able to pop out the concrete and slide it right out saving us an immense amount of time and mess to clean up.
With the existing dock pits, we were able to take the existing concrete, throw it on the dump truck and haul it away, leaving the new pit ready for rebar installation and framing for the new pit itself.
For the dock pits that did not exist, we used a small excavator to dig out the stone base to its proper elevation ready to pour for the base of the new dock pit.
Install Rebar Reinforcements
Every new installation of concrete demands some sort of rebar reinforcement. For dock pits we install #5 rebar every 12” on center tying in the pit base to the warehouse floor.
In our case of this job, we used hammer drills to create openings for the rebar in both the pit base and warehouse floor, installed the rebar, tied it together and sealed the rebar to the concrete with epoxy.
Some villages require the addition of epoxy to each rebar attachment while others do not make it mandatory.
With the cages installed in each pit, its time to frame.
Framing (Pit to New Size Pit)
With the old dock levelers removed, pit opening widened, and old base untouched; we are ready to install rebar reinforcement and frame up the new dock levelers. Precision is vital for this phase of our project.
#1 focus of framing these new pits is to make sure they are square.
If what we frame is off square by more than 1/2”, then the new dock levelers will not fit and we will need to start the job all over again.
It’s like trying to fit a square into a rhombus, it just wont happen and its going to cost you a boat load of money.
#2 is to make sure you have the correct heights for the new pit.
This is another measurement that is mandated by the size of the dock leveler being installed.
If the pit is too deep or too shallow it will create a failure of welding point and you will have to go in and fix the problem which is not an easy fix.
Pour and Finish
You are ready to pour concrete and get these docks ready for leveler installations.
We used regular 6 bag mix with half air to help reduce the amount of pinholes in the hard trowel finish.
Using a vibrator may be a bit too much for these pits because you do not want to risk any blow outs, so we tap our forms with hammers and jitterbug the concrete with shovels to make sure all holes are filled with concrete.
When the time is right, grab your trowels and get to work. Most warehouse slabs are a hard trowel finish, so we finish to match the existing slab.
I hope this article helped, if you need any guidance or someone to install your new dock levelers, reach out and I will connect you with someone who can help!
