Pump Jack Scaffolding
As mentioned in our Part 1 Scaffolding Toolbox Talk, there are many varieties of working platforms that fall into the category of “Scaffolding”. Another very common type of scaffolding found on a residential construction site is called Pump Jack Scaffolding.
Typically used by Siding installers, Pump Jacks are an exterior use system made up of 2 vertical poles with adjustable brackets that hold up the working surface.
Poles and Brackets
- Pump jack brackets, braces, and accessories shall be fabricated from metal plates and angles. Each bracket shall have 2 positive gripping mechanisms to prevent any failure or slippage.
- Most Poles are aluminum with a rubber face, this makes it easier to move around the jobsite and comply with the strength and grip requirements.
- If poles are made of wood, then the pole lumber shall be straight-grained and free of shakes, large loose or dead knots, and other defects that might impair strength.
- Be secured to the structure by rigid triangular bracing, or equivalent, at the bottom, top, and other points necessary to provide a maximum vertical spacing of not more than 10 feet between braces. Each Brace shall be capable of supporting not less than 225 pounds of tension or compression.
- Be made of 2, 2 by 4s of Douglas fir, or the equivalent. Shall not exceed 30 ft in height. No more than 2 employees shall be on one set of pump jacks at one time.
Manufacturers set the load ratings as Light, Medium, and Heavy Duty. Careful consideration should be taken to calculate the total weight being applied to the system to prevent failure. The weight of the individuals on the plank, the weight of the plank, the tools and materials all need to be taken into account.
- Light Duty – 25 lbs per sq/ft applied uniformly over the entire span
- One Person placed at the center span (250 lbs)
- Medium Duty – 50 lbs per sq/ft applied uniformly over the entire span
- Two People, 250 lbs placed at least 18” from center span
- Heavy Duty – 75 lbs per sq/ft applied uniformly over the entire span
- Three People, 250 lbs spaced in thirds over the span
Guard Rails – 1926.451(g)(4)
Under Subpart L all scaffolding requires guardrails along the open edges. Many people set up Pump Jacks with a work bench which doubles as the Top Rail. A mesh net system also doubles as toe board and falling object protection.
The working side of the scaffolding shall remain open as to allow the installation of materials. However, the open side cannot be more than 14” from the building face to the leading edge of the working surface.
Don’t leave the ends open! The left and right sides of this scaffold are often forgotten about, they too must be guarded to prevent the user from walking off the edge.
In a typical use case of Pump Jacks, the most dangerous overhead danger will be making contact with electrical power lines while moving/setting up the poles. Always do a thorough walk around the building to complete a Job Hazard Assessment before taking the first piece of equipment off the truck.
During the set up, if electrical lines are present you must maintain a safe distance from them. A standard residential power line carries 240 volts, so a minimum distance of 3’ is required.
Set Up and Training
The actual regulation for this type of scaffolding is relatively short considering the dangers involved. The standards for Scaffolding and Fall Protection are quite extensive. It takes a competent person to understand all of the risks involved and to see the importance of proper set up and use of the equipment. Do not let un-trained, or inexperienced people to set up and use any type of scaffolding.
You might also find this Toolbox Talk helpful: Fall Protection