Frequently Asked Questions
Cold Formed SteelTranscon Steel has compiled a list of some of most commonly asked questions from owners, designers, and builders whom are investigating the use of cold formed steel for their upcoming project.
Will a steel framed home look different than other homes in the development?
No, only if you want it to. In fact, because of steel's properties your architect can design your home with larger open spaces. With steel framing, walls will remain straight and true, preventing call backs due to nail pops and shrinkage cracks. Finishes can be the same as you are accustomed to using.
2. Question Does steel framing interfere with wireless internet, radio or television reception?
No. Radio, television, and satellite waves pass through the spaces between the studs, allowing the use of all household appliances, including computer and telephones, without any interference.
Remember, most commercials office buildings are built with steel framing members.
3. Question Is it easy to hang pictures on steel framed walls?
Yes. Lighter pictures can be hung from the drywall with toggle bolts or hangers. Heavier objects can be hung with screws attached directly into the steel stud, easily found with a magnet.
4. Question Is a steel frame safe in lightning storms?
Yes. A steel frame actually allows more protection for the occupants in the case of lightning. Steel provides a path for the lightning straight to the ground, reducing the likelihood of explosions or secondary fires. Steel skyscrapers have provided occupants with safe offices and residence for years.
5. Question Can a steel framed home be remodeled?
Yes. Since steel framing allows for larger spans in the design of the home, less interior load bearing walls are needed, making renovation very easy while allowing more flexibility in design.
6. Question Will a steel framed home rust?
No. The use of zinc coating on the steel framing protects the steel from corrosion for the life of the structure.
For the Professional
7. Question How does the cost of steel framing compare to wood framing?
Using historical averages, steel framing material prices have been less expensive than wood framing. However, if the builder, framing contractor or other subcontractor is new to steel, then labor costs could account for a $1.00 - 2.50 per square foot premium over wood. The steel industry continues to improve the processes by which steel homes are built, bringing hard construction costs down to a minimum, so that builders will be able to enjoy a competitive and stable framing package price.
8. Question Is it easy to learn how to use steel instead of wood?
Steel framing uses the same layout, spacing and general framing techniques used in traditional wood framing, so learning how to use steel is very easy, because many of the same principles apply. The only difference lies in fastening and cutting. With steel, typically a fastener (screw) and screw gun is used, vs. a nail and nail gun with wood - and steel is cut with a carbide or metal cutting blade.
9. Question How do I start using steel framing in homes?
Many builders start by using steel framing in one or more applications of the home, e.g., floors, walls (non-load bearing and load bearing), ceilings, roofs and rafters. Today, two steel framing products offer a cost advantage over wood: floors and interior walls. Steel studs in interior walls can be less expensive than a wood stud, especially when steel studs are spaced at 24" on center and also provide an uncommonly straight wall. Steel floor joists are generally cheaper than dimensional lumber products and perform better.
If builders use steel floors or interior walls, they can realize cost efficiencies where steel is cheaper to install and simultaneously train their framing contractor and other subcontractors, one steel framing application at a time.
10. Question Is there a training manual that I can use to train my framing contractor and other subcontractors on steel?
Yes. It is called the Residential Steel Framing National Training Curriculum. Typically used in vo-tech schools, community colleges, apprenticeship programs, or any training institution, the Curriculum is also used as a self-study program. It provides the student with a step-by-step illustrated guide for building a home with steel. You can order the Curriculum on-line at www.SteelFramingAlliance.com, or by calling the Steel Framing Alliance (SFA) headquarters, 202.785.2022. You can also purchase the student manual of the Curriculum on CD-ROM.
11. Question How do I insulate my steel framed home?
You will need at least as much cavity insulation (providing the same R-value) in a steel framed home as with wood. In some markets, you will need to add exterior rigid insulation. Consult SFA's Thermal Design Guide for Exterior Walls available on-line at www.SteelFramingAlliance.com. Note: Open shape metal studs will require the use of full width batts, commonly used in commercial framing and available at most building material dealers.
12. Question What fastening system should I use with a steel framed home?
Typically self-drilling, self-tapping screws are used to fasten steel members together, or to apply sheathing, subflooring, drywall, or siding. Publications that offer more information about fasteners are available for free downloads at the SFA Web site, www.SteelFramingAlliance.com, as are publications that provide more in-depth guidance.
13. Question Is there a formula to convert wind speed to lateral load, so a contractor can refer to the curtain wall tables in the SSMA catalog to decide which stud will work for their particular application?
Unfortunately, there is not a formula to convert wind speed to wind pressure. This conversion is covered by the building codes; the codes in all jurisdictions are not always the same. Over the years, the wind speed and pressure used to design a particular size and type of structure will change as the code requirements change. A building located in a 90 mile per hour wind zone in North Carolina may not have the same wind pressure as a building located in a 90 mile per hour wind zone in Texas, because the building code and version of the code adopted may be different.
Also, there are many factors that go into the conversion: building height, building use, building shape, terrain and location of adjacent structures. One building may have multiple wind pressures, even though it is designed for the same wind speed. Buildings such as hospitals, fire stations and police stations must be designed for higher pressures because of their use, according to the codes.
There are also two classifications of building components and systems that must be designed for two types of wind loading. "Components and cladding" must be designed for relatively localized forces, since the wind may load these portions of a building directly. the "main wind force resisting system" provides overall lateral stability to the structure. The tributary area supported by a particular portion of the structure can also affect the design load required. A longer wall stud, for example, may sometimes be designed for a lesser wind pressure than a short stud. This is because a local gust can produce very high pressures over a small area, whereas a stud or building element spanning a longer distance will not likely have this higher pressure over its entire length.
14. Question What suggestions do you have for mounting cabinets to the steel studs most securely? I expect to use 18 mil studs for the application. I understand screws do not hold as well in the steel as opposed to wood studs, but the many advantages of steel have me hoping I can come up with a good solution for the cabinets. I don't have exact numbers, but I expect the cabinets to be less than 1 foot away from the wall, and hold several hundred pounds. Are anchors a good solution? If so, what type of anchors? Would drilling into the thin steel compromise the strength of the stud, if I placed an anchor in the stud requiring a 1/2" - 1" diameter hole?
When planning construction for cabinet attachment to steel framing, it is best to install a continuous strap or segment of track along the top and bottom of the areas where the cabinets are to be supported. These are shown in the details on the SSMA website (www.SSMA.com) on pages 41 and 42; they are called backing. When attaching the backing, use #10 screws. The SSMA tech catalog gives shear values for these screws in steel-to-steel connections, so use as many screws as you need from the track or strap to each stud.
Note that for the type of loads you are talking about, I recommend a track rather than a strap; preferably 43 mil steel or thicker. Of course, this depends on how many fasteners you will be using to attach the cabinets to the track; the more fasteners you have, the lighter the load will be on any one fastener. If the wall is already up, it is a bit more difficult to plan your cabinet supports, but it still may be done. The shear and pullout capacity of fasteners in 18 mil material is much less than it would be in 43 mil material: strength of the screw connection is directly related to thickness. A sample load value for a #8 screw would be 66 pounds of shear and 39 pounds of pullout (values are from the SSMA Product Technical Information catalog, also found on the SSMA website; and are calculated based on the American Iron and Steel Institute's North American Specification for the Design of Cold-Formed Steel Structural Members.) Based on the loads, screws of this diameter may not be the best option, unless you are able to get multiple screws in each stud.
Pre-drilling and installing some sort of expansion anchors, such as molly-bolts, can be done, but holes larger than 1/4 can reduce the bending and axial capacity of a stud when drilled through the flange. For interior curtain-wall framing, this is usually not a big issue, unless the walls are really tall. Be careful when using the hardened screws for steel framing to support wall loads like this. Because the screws are hardened to make the driller point strong enough to cut through steel, the screws have little capacity to bend and can fracture suddenly when overloaded. Therefore, you won't get any warning signs, such as sagging connections, when someone puts too much heavy stuff in them, or tries to use them as a ladder to replace a light bulb!
15. Question Are there safety or health manuals pertaining to the manufacturing of cold formed steel in the plant or the use of the cold formed steel in the field?
The International Code Council has produced information required for quality control procedures for the manufacture of steel framing. It is available at the following web site: http://www.icc-es.org/Criteria/ac.shtml.
The criterion for quality control is AC10; and the criterion for studs and track is AC46. However, there is no listing pertaining to safety and health in manufacturing; these are primarily for quality control and consistency in manufacturing the product. There are other organizations, such as the American Welding Society, that may have specific manuals that deal with safety in welding, but this is only one of several processes that are used in steel-framing manufacture and field use.
The best bet may be one of the framing guides from the Steel Framing Alliance (www.steelframing.org). The Steel Framing Alliance has several field guides, including a Steel Wall Guide and a Steel Floor Guide. Although not specifically designed for health and safety, these guides give some best practices that can lead to a safer structure, as well as safer jobsite.
However, using framing manufacturer and tool manufacturer instructions and guidelines are often your best bet both in the factory and on the jobsite. Manufacturers are required to maintain Material Safety Data Sheets. These documents are available on the web sites of some of the framing and fastener manufacturers.
16. Question Can mold grow on steel studs?
Mold requires three things to grow:
Steel does not contain any organic material and therefore cannot support mold growth. However, if someone or something has left a residue of organic material on the steel framing, there is a chance that given the right conditions, mold could grow. As with any framing material, the best practice is to keep the steel studs dry. Even if they get wet during construction, or there is a one-time event such as a pipe bursting in a wall, there should be no long-term problem if the cavity is dried out properly. It is persistent wetting, such as a steady plumbing or roof leak, which causes the greatest risk of supporting mold. Even then, the mold will most likely grow on organic surfaces, such as the paper facing of the gypsum board or wood framing members, rather than steel.
In steel framing, when everything is clean and dry, there will be no opportunity for the mold to grow. Note that the Steel Framing Alliance has an excellent publication on this issue: listed under the "About Steel Framing" bar on the home page, go to "Issue Papers" for a free download of the issue paper on mold.
17. Question Are there specific provisions in the 2003 IBC for the anchorage of load bearing exterior and non load bearing exterior cold formed steel walls to the foundation? What do you recommend?
There are not specific provisions in the International Code Council's International Building Code (IBC) for anchorage of cold-formed steel framed walls; but there are provisions in the International Residential Code (IRC) for these walls. The IRC not only has details for this connection, but references the Standard for Cold-Formed Steel Framing-Prescriptive Method (AISI 2001) for anchorage, which is typically anchor bolts through the bottom track at 4' on center.
For non-prescriptive construction, there are several different methods for wall anchorage that are acceptable depending upon the load and the seismic zone. The most common method is powder actuated pins. Companies like Hilti and ITW Ramset have technical data on the holding power in structural steel and concrete; for the bearing in cold-formed steel, use the bolt bearing equations in chapter E of the North American Specification for the Design of Cold-Formed Steel Structures (AISI, 2001). These also may be used for other anchorage to concrete, such as expansion bolts, threaded anchors (such as Tapcon and Kwik-Con,) Spike anchors by Powers Rawl and others. Recent developments in epoxy anchors have made them very popular with cold-formed steel framing; they can be installed in the exact location required, and the edge distance and spacing restrictions are less than the expansion anchors.
18. Question Why build with steel?
Residential steel framing members are cost effective, light weight, easy to handle, and manufactured in conditions that allow strict quality control. When designed properly, the result is a solid, non-combustible, and durable structure. Because steel can be pre-cut to desired lengths and is a stable material, you don't need to sort out defective pieces and can erect a frame faster. Also, steel scrap has value and can be recycled.
Steel framing discourages mold, frustrates termites, provides more safety in electrical storms, and stands straighter, stronger and longer. If you live in an earthquake zone, steel framing is stronger than wood, giving it more stability against unexpected natural events. If unstable soils are prevalent in your area, steel framing weighs less than wood, putting less pressure on the foundation systems.
19. Question What is an open web system?
Open web, or parallel flat chord trusses, represent the predominate type of floor truss used in homes.
They typically consist of a wood top and bottom chord, usually 2x4 material, and wood web materials connected at joints with metal plates. A few manufacturers use steel webs.
One advantage of open web over dimension lumber or I-joists is that the open space between web members allows for easier routing of utilities and ductwork. Open web floor trusses eliminate the need for field cuts for utility installations, reducing the risk of structural damage in the field. However, truss dimensions must be known in advance to be within fairly close tolerances.
Manufacturers and codes generally do not permit trusses to be trimmed or altered in the field.
Transcon Steel supplies the Mega Joist as an alternative to floor trusses. The Mega Joist system is an open web joist that provides trade friendly access across the entire member.
20. Question What about the environmental impact of steel construction?
21. Question What about cost?
The price of steel has been relatively constant over the last decade. While the price of traditional framing materials has been erratic and growing at a rate much faster than inflation, steel prices have only experienced small quarterly adjustments. Builders interviewed nationwide have affirmed that framing with steel is less expensive than traditional framing.
22. Question What about about?
23. Question What about earthquakes and hurricanes?
24. Question Is steel much different than wood framing methods?
Steel framing uses the same layout, spacing and general framing techniques used in traditional wood framing. The only difference lies in fastening and cutting. Instead of nails and nail guns, you fasten steel framing with screws and drills. (Sheathing boards can still be fastened with pneumatic nailing guns.)
You cut cold formed steel with a carbide or metal cutting blade or plasma torch.
25. Question As a builder, how do I get started with steel framing?
If you'd like to start slow, use steel in just one or two areas. We recommend starting with floors and interior walls because of their cost advantages over wood.
Steel studs in interior walls can be less expensive than wood, especially when steel studs are spaced 24" on center, a wider spacing that steel makes possible. Steel also creates an uncommonly straight wall.
In the floor, steel joists are generally cheaper than dimensional lumber and perform better. Once your framing contractor and other subcontractors see how easy steel framing is to learn and master, it's a simple matter to use it in ceilings, roofs and rafters.
26. Question How fast can Transcon Steel deliver?
Transcon Steel can manufacture up to 30 miles of steel per day. We keep coil stock on the floor at all times and can generally have delivery within 2-3 days. For larger high-rise projects, steel can be delivered in multiple phases to meet construction jobsite and framing requirements.
27. Question How experienced are your engineers?
Transcon Steel has developed a network of engineers globally that can provide regional engineering expertise for our projects. If you are an engineer, please contact Transcon Steel so that we may present to you the design standards that can be applied to your projects for any type of construction from hurricane, seismic, explosion protection, and more.
28. Question Where can Transcon Steel deliver?
Transcon Steel has both domestic and international freight forwarding companies that can deliver product globally on both US and foreign flag ships. In North America, over land transportation can be provided by US, Canadian or Mexican shipment companies.
29. Question What is the difference between cold formed steel products and cold formed steel systems?
Anybody can design one truss or one wall, but a system requires looking at the roof or the structure as a whole. That way, we avoid under-designing one area and over-designing another. We can see where strength in one area will lend strength to another, offering opportunities for efficiencies. Or we may see where reinforcement is necessary because of seemingly unrelated forces.
By viewing the building as a whole, the whole system works as one.