Open Web Steel Joist (OWSJ) Reinforcement
We provide (OWSJ) open web steel joist reinforcement welding service prior HVAC contractors' heavy unit installation or solar panels installation. Joist and roof truss or open web steel joist (OWSJ) reinforcement projects occur when owners plan to add additional weight on the roof. Or plan to hang additional weigh off the joists or roof trusses. Adding a heavy HVAC unit installed by HVAC contractors will usually require joist reinforcement. Solar panels installation will also require such reinforcement. Recently we have been involved also in the other aspect of joist reinforcement which involved hanging additional weight off the OWSJ. Apparently, hanging a sliding security door off the OWSJs also requires their reinforcement.
CWB certified welder receives drawing approved by professional engineer
When CWB certified welder receives an approved by professional engineer drawing, it is a time to start quoting. Now is a time to visit the future construction site. And confirm dimensions and other details from the drawing with the reality on the ground. We always visit the construction site prior quoting in order to avoid unpleasant surprises.
Professional engineers are busy people, and they tend to send their young assistants to visit the construction site to confirm the details. Professional engineers usually have access to original drawings of buildings, and they produce joist reinforcement drawing of the original drawing. Unfortunately, the original drawings do not contain changes that could happen over the years, and definitely do not contain details that will affect the work of a CWB certified welder.
Initial welder’s inspection of OWSJ project
The welder should treat the initial inspection of OWSJ project very seriously. The inspection should cover:
- environmental factors, and
- approach to owsj reinforcement.
Having a chat with a site supervisor is not a bad idea since they will coordinate the work of contractors surrounding you. And they can help with some technical issues.
Obstacles affecting welder’s job reinforcing OWSJ
Any obstacles located on the ground or between joists will affect your OWSJ reinforcement welding work. Any gas piping, water piping, or electrical wires will form obstacles that you will have to be concerned with. What you want to see is clean OWSJs without any obstacles. Good site supervisors understand it and they have a cleaning crew stripping all obstacles.
When on the ground pay attention to machinery that can not be moved, openings in the floor, and a general congestion between the walls. These obstacles could make certain parts of OWSJs not accessible or very difficult to reach. Once again, what you want to see is open floor without any obstacles.
Any obstacles on the ground or between joist will slow you down and cost you lost time. You will have to go around these obstacles and you will spend time to communicate issues to a builder or a site supervisor. Therefore you have to quote higher when you see obstacles on the ground and between the joists.
Environmental factors affecting OWSJ reinforcement
OWSJs are close to the ceiling where temperatures are high, and dust is everywhere. Anybody who has ever worked under the ceiling knows how misleading these temperatures are. Even in winter, workers on the floor are wearing light jackets, whereas welders working close to the roof are experiencing warm temperatures.
Doing joist reinforcement jobs during beautiful Canadian summers could cause heat stroke. Welders should have lots of water on their lifts when working close to the roof. Welding in hot temperature is very difficult. You can ask any welder how inconvenient welding is when you are sweating profusely. And while your glasses are foggy, you can't see anything.
Removing paint from a metal surface prior welding is a normal procedure. Following this rule when doing OWSJs reinforcement is impractical on most of the projects. The thin layer of primer covers the steel and it burns out nicely when welding. However, sometimes steel joist is covered in heavy paint that contains lead and then the welding becomes more hazardous.
When our welder will face high temperature, heavy dust and lead contained paint, than our quote will go higher.
Technical approach to OWSJs reinforcement for heavy load on the roof
The reinforcement of OWSJs involves bottom chord, top chord and web reinforcement. The welding process involves stitch welding round rods to bottom chord and top chord and then welding angles to web. The round rods must be pushed to the corner of the chord angle and then welded. Sometimes, however, instead of round rods welded on the angles the professional engineer requires flat bars going at the bottom of the angle’s leg.
I personally prefer the flat bar’s approach since it makes welding more consistent to CWB rules. The joint shape when welding round rods to the angle is a rather flange than bevel or square which is unusual for structural welding. And many CWB welders have never experienced welding this joint. Additionally, when welding a thick round rod to thin angles most welders burn the angles through.
Another area of concern is to weld angles to the web. The web element is a rather thin round rod and the welder must make a semi-vertical weld between the rounded rod and the angle. This is the area prone to burn through. We were occasionally involved over the years in repairing the welding mistakes made by some welders who burn severely through the angles. Fortunately, for many of these welders who rushed through the project, the inspectors did not use the zoom booms or scissor lift to inspect their whole work.
Reinforcement of OWSJ for hanging sliding security door
The reinforcement of OWSJ’s for hanging sliding security door is not a standardized thing. Certainly, the approved drawing is provided but the contact with a sliding security door installer is paramount due to obstacles that are difficult to go around and required special modifications. The installer’s insistence to precise line where the sliding security door should go causes sometimes unexpected difficulties and his input is paramount to project success.
The market is full of part-time welders
The market is full of part-time welders that are CWB certified and work occasionally for contractors or run part-time businesses. These welders try to accomplish your projects on afternoons or on the weekends. Most of these welders work “full time” for one of the dominant unions in Ontario whether it is iron workers, millwrights, electricians, or labours. They offer low rates and they rush on the job. I think there are no “bad” welders among CWB certified welders, but there are plenty of “bad” low quotes and plenty of welds that must be closely inspected. Simply put there are plenty of people who rush through the project due to rather uncomfortable conditions.
Quoting OWSJ’s reinforcement project
When quoting properly OWSJ’s reinforcement project, one should consider labour, material, consumables, obstacles, environmental factors, and technical approach to OWSJ reinforcement.