Construction Site Health Precautions
By Kristof Irwin and M. Walker
Travis County Cumulative Cases (Log) and New Daily Cases (Linear) + 14 Day Moving Average as of July 5th, courtesy of Reddit user u/RationalAnarchy
Back in March, we wrote about ways to improve indoor air quality in our houses and buildings as much of society shifted to working from home. Here we are nearly 4 months later; commerce has re-opened and COVID-19 infection rates are skyrocketing. Just take a look at Travis County data from July 4th weekend and you can see our curve growing rapidly the last few weeks. Austin is certainly not alone showing such trends and at the time this post was written, there is a state-wide mask ordinance issued via executive order by the Texas governor.
But houses and buildings can't be built over a Zoom call and construction continues on. We all need to do all we can to end this period of uncontrolled community spread, particularly on construction jobsites, since construction workers have been so hard hit by infections. Like any construction project, there are both quantitative and qualitative requirements of a team to bring a building to life. With these facts in mind, Positive Energy offers the following list of ideas to support the health of your construction team on the jobsite.
Be Realistic
We understand the realities of construction. It’s not easy even in favorable conditions. Expect downside impacts from this pandemic and know you’re not the only one out there who is slowed down. It will take longer to get the same work done while also maintaining safe practices. Help clients and design team members understand the reality on the jobsite as the constraints of the pandemic challenge pre-COVID-19 expectations.
Be Professional & Cooperative
Company culture on the jobsite has never been more important. Now is the time for the individual, personal exertion in the sense of maintaining the discipline to maintain safe practices even when it’s inconvenient and uncomfortable and impedes productivity. Teamwork and a shared mission of safety are crucial to keeping everyone on site safe and keeping the project on track. Keeping teams safe in a pandemic should be a badge of honor.
Be Responsible
Know the rules and follow them. The basics must include health checks, sign-in/out for contact tracing, masks/PPE, frequent hand washing/sanitizing, and strict distancing. Of course specifics vary from jurisdiction to jurisdiction, but most cities have made the resources readily available to start the conversation.
Be Accountable
If the rules are not posted or enforced or you're not clear on them, speak up. Leave the jobsite if COVID safety precautions are not being followed.
Remember that power dynamics between client and GC / GC and sub contractor set the tone for accountability. Without transparency and good communication, the folks at the bottom of the power structure will ultimately be the ones who suffer. Use your leverage in the situation to keep yourself and others safe.
Minimize Speaking Inside
Go outside for planning and coordination, particularly for group conversations (remember that distance and masks are still necessary outside).
Take breaks and bio-breaks safely. Regularly disinfect the toilets and wash/sterilize your hands after using them.
Keep It Extra Clean
Regularly wipe and disinfect surfaces and HEPA vacuum the jobsite to prevent dust and debris build up. Do this on a schedule not to exceed once every 4 hours. Even better is to designate someone to perform continuous jobsite cleaning and dusting throughout the occupied period.
Ventilate Working Environments
Air exchange is important. Use fans to move outside air in and inside air out. CO2 levels can be used as a guiding metric. Measure CO2 levels to maintain at less than 1000ppm. Unless the jobsite is basically wide open, target a minimum of 3 air changes per house (ACH). This mean both fans for moving the air in and then back out. For closed/indoor construction ventilation will decrease thermal comfort and impair the ability to maintain dry air conditions needed for many interior surface installations and finishes (more on that later).
Filter The Air In The Workspace
Image courtesy of Greyson Joralemon
Use portable room air filters rated at a minimum of MERV-13. Construction sites produce lots of dust and particles so HEPA grade portable filtration will rapidly load and become ineffective. DIY portable air filters can be made by taping a MERV-13 filter cartridge to the back (suction side) of a simple box fan. Keeping the ordinary airborne jobsite pollution down will aid in the respiratory health of the team and the same filtration system can also prevent viral shedding in the air.
Use UV-C Air and Surface Disinfection Systems
UV-C is the portion of the UV spectrum used for ultraviolet germicidal irradiation (UVGI). While the topic is complex, these systems can be safely used with some basic understanding. Typically UVGI applications are:
In-duct systems - Titanium doped UV-C lamps emitting at 254nm is recommended for in-duct UVGI systems. Broad spectrum UV from residential grade systems such as Reme-Halo can also be effective. Be sure that these systems do not emit radiation into occupied spaces. This is not a recommendation for Reme-Halo or other UV lamps in home duct systems. Only for construction sites with intermittent occupancy. Except for COVID, the general recommendation is not to do indoor air chemistry in occupied spaces.
Upper air systems - These are fixed UV-C lamps that can operate with/without ozone production and are appropriate for use in unoccupied/occupied spaces.
UV Robots - These are portable high output UV-C air and surface treatment units. These can be used after hours or periodically during the day, while the site is unoccupied, to rapidly and effectively sterilize air and surfaces.
Recognize & Deal With The Elevated Risks Of Unventilated Jobsites
When ventilation causes elevated temperature and humidity that it interferes with construction, for example installing hardwood flooring or drying paint/sheetrock, be more conservative with jobsite access. Limit the number of workers within each contiguous indoor air volume. No more than one person per 150SF of floor area. This will increase in confined areas such as attics, crawl spaces or other confined areas.
Of course these ideas are subject to change and we’ll keep them up-to-date as the situation evolves. If you’ve seen some great examples of jobsite safety to prevent virus spread, let us know. We want to hear about the good work being done. Similarly, if you have ideas for how we can improve this resource for more teams, we’d love to hear from you. Use the button below to submit your feedback. These submissions will be kept private unless we speak with you about publishing first.
