What Keeps Me Up at Night: Know Your Choices When Considering Cell Construction Materials
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Offner |
When I think about my experiences and my career path in corrections design and construction, it often seems like I have represented professional design and construction management firms while performing public-sector therapy with my clients. All of my clients have one thing in common — they want to make the right choice.
There are several types of cells to choose from with many variables. Gone are the days of only three choices — steel bars, poured-in-place concrete cells or cells constructed with concrete masonry units. Today, we have the old methods of cell construction and newer methods of construction, such as modular precast concrete cells, modular steel cells and pre-engineered steel panel cells.
Cells can be delivered partially furnished or fully furnished with wall-mounted bunks and desks. Some cells have the ability to sanitize or arrive negative-pressure prepped. Some cells use seamless surfaces, or epoxy coating. Cells can be padded, lightweight, stackable, no maintenance or low maintenance, with or without showers, and outfitted with stainless steel or ceramic fixtures, among other amenities.
Deciding what type of cell to purchase is never a simple choice even though there are vendors who can make it sound like your choice is clear, as long as it’s their product. Every premanufactured product has its inherent virtues and weaknesses.
When I start my research into what will serve my client best, I start with geography. There is currently a big competition for construction labor, manpower and materials in many areas of United States. The Gulf Coast and the Las Vegas areas have the largest shortage of resources and the situation won’t improve for another three years, according to reports. It’s almost like there is a giant vacuum hose sucking every hammer-swinging, wrench-turning human within 200 miles of the Gulf Coast and Las Vegas to the casino hotel, Federal Emergency Management Agency and residential construction markets.
The workers are getting overtime pay and some receive guaranteed housing. Recommending the use of a labor-intensive assembly for cell construction in these regions is probably not a good solution. I would not recommend masonry or cast-in-place cells in Arizona, Nevada and parts of Utah, California, Colorado, Florida, Georgia, Tennessee and Texas.
In the Mid-Atlantic, Northeast, Great Lakes and Northwest areas of the country, construction manpower is also in demand but skilled craftsman are a bit more abundant. Unit masonry products and cast-in-place concrete is more likely a competitive option in those areas.
Cells that historically use the least amount of labor to construct are modular precast concrete and modular steel cells. In the mid-1980s, they were virtually unheard of, but today they are practically the preferred assemblies for cell construction.
Modular cells are great products that are durable and have several options, including flexibility in configuration. With the exception of one modular precast concrete cell manufacturer that usually sets up its plant at or near the job site, transportation costs can be a determining factor in selecting a modular concrete cell.
Shipping preassembled products by road, rail or sea is expensive, and growing more costly every day. There are ways to make the modular precast concrete products lighter and more durable by using carbon fiber mesh reinforcing. Using this material could reduce transportation costs dramatically because the product will be about 25 percent lighter.
However, some prison and jail management officials believe inmates will be able to pick their way out of a wall that doesn’t have solid steel bars embedded in them. Despite the perceived management issues, the corrections industry should take a closer look at using carbon fiber in walls that don’t breach the secure perimeter to reduce the weight of the precast cell. Modular concrete cells are great products, and very competitively priced depending on the location.
Modular steel cells are lighter than modular precast concrete cells so shipping costs are lower than precast concrete cells. Pre-engineered panel steel cells are easier to ship and you can get more cells on a flatbed trailer when they are unassembled. They use minimal manpower to assemble, but highly skilled welders are recommended.
The modular steel cell is usually shipped complete and — like the modular concrete cell — once they are set it in place you are practically done. Because steel cells are made out of heavy-gauge hollow metal, some use concrete-filled steel panels.
Because the walls are thinner than concrete cells, the overall building square footages can be smaller, which could mean lower overall construction costs and lower operating costs.
There are two other considerations for modular designs. In active seismic areas, modular cells may require some expensive and complicated earthquake-safe connections if you are considering stacking cells on top of one another.
Another inherent issue is the variability of erection tolerances that can cause unexpected field conditions during construction. This is a normal occurrence when using different materials and building types and should be planned for during the design process.
An example: Steel structures have a normal erection tolerance of 1/8 inch in 10-feet +/- plumb and level. Most modular units have an erection tolerance of 1/4 inch in 10 feet. This variation is usually a bigger problem in the vertical lines than the horizontal line.
If I am looking for a solution for a client’s renovation or retrofit I’ll first consider using either modular steel cells, or pre-engineered steel panel cells. While both are very suitable for new construction, they are also very good options for renovations and retrofits.
If a client wants to convert a warehouse into a housing unit, pre-engineered steel panels can be delivered through the front door and assembled on site or an end wall of the building can be opened and the steel cell can be moved into position to create added secure accommodations.
When the work takes place inside the secure perimeter there is a higher degree of difficulty executing this type of project. Extreme care must be taken in the exact planning and coordination of construction with facility operations to avoid a security breach. The New York State Office of General Services in partnership with the New York State Department of Correctional Services accomplished this type of construction during a statewide expansion several years ago with great success.
When it comes to amenities and quality, I have found nearly every premanufactured product can provide you with what you need behind the cell door — whether it be medical isolation cells, mental health or administrative segregation cells, single bunk, double bunk, quads (four inmates to a modular cell) or dual quads (eight inmates to a modular cell). Showers and desks are easily prepped for and can be fashioned into the cell or easily installed after the cell is in place.
In the final analysis, it all comes down to cost. On a cost-per-bed basis it will be difficult to find an option that is cheaper than modular concrete cells in many locations around the country. There are more cell manufacturers dispersed throughout the United States than other types of cell manufacturers. The price per bed has also been traditionally better than masonry and cast-in-place concrete because the precast uses less labor to construct.
A back door savings to using precast is most prison and jail designs are usually configured around a particular cell manufacturer’s footprint. To reduce their cost to design a prison or jail, many design firms have adopted a standard cell configuration into their basic design concepts. This practice reduces the cost to design and the savings are passed on to the client.
Some modular precasters have been around for more than 25 years. Major modular precast firms, such as Oldcastle, Rotondo Weirich and Tindall, usually have experience working in most parts of the country. When you know what to expect, risk is lower. When risk is lower, prices go down.
Other types of cells can sometimes be a more cost-effective solution. Standard cast-in-place concrete steel forms can be re-engineered, and plywood concrete forms and concrete masonry units can be cut in the field to meet any projects needs and requirements.
Similar to the concrete precasters, SteelCell Inc., Kullman and TrussBilt have developed very aggressive pricing schemes, and are gaining project experience in many parts of the United States. Steel cells also have an added value in smaller overall external size, which is a benefit that precast concrete cannot match.
Steel cells also have greater flexibility, and they can be used in new and renovation/retrofits without as much manpower. You can turn an old warehouse into a housing unit using steel cells, which won’t be as cost effective with modular precast.
Finally, before I make a recommendation to my client, I talk to all of the manufacturers. When all of the research is complete, I can offer my client a suggestion for the cell type that will have the best value. I sleep better at night knowing I have done everything I could to help my client make an informed choice.
Gregory J. Offner is vice president of DMJM H+N – AECOM located in Arlington, Va., and a member of the Correctional News Editorial Advisory Board.
