Steel Building Now

Pre-Fabricated, Pre-engineered Steel Building Structural Framework Designs

admin — Thu, 27 Dec 2007 09:18:59 +0000

There are three major steel structure framework styles to consider when planning your pre-fabricated, pre-engineered steel building venture: clear span, modular, or single slope. Pre-engineered steel structure system sellers and fabricators use a precise planning and pricing process whether you are buying a finished product by phone or via the internet, regardless of which building style you choose. The following information should help you determine the best approach for your project.
The most popular choice on the pre-engineered steel building market right now is the wide span (also called clear span or free span) rigid framework structure. This design is the perfect solution when you need a large, unobstructed interior space. A clear span rigid steel frame structure is economical to build, provides dependability and durability, and is also adaptable to any configuration. There are no inner load-bearing column supports needed, so this system it is often used for industrial facilities, stores, sports facilities, farm and ranch structures. The interior can easily be divided using partitions into offices, rooms and other private areas. Since these internal partitions are non-load bearing, you can reposition your floor design as needed. Clear span construction is extremely cost effective for structures up to 150 feet wide. For structure widths over 150 feet wide up to the maximum available width of 300 feet, the cost per square foot will increase due to the fact that the structural framework must be made sturdier to handle the increased load caused by the broad distance.
The second category is the modular structural framework. Unlike clear span construction, modular steel building frames use interior load bearing pillars. The use of inner supports generally decreases the cost of both the framework and foundation, as loads are distributed more evenly. Modular design works well for an all-steel structure or plant that needs moderate interior space. The cost savings over clear span are most significant for structures up to about 80 feet across, but building widths up to 150 feet can also be economically feasible. Structures greater than 150 feet wide will usually include inside supports, unless the planned use of the building justifies the extra expense of clear span. �
The single slope frame is the third style of pre-fabricated steel building. These structures have a distinctive appearance, since they have varying eave heights on each building sidewall. The rooftop pitches up from the front of the structure all the way to the back. Since the eave height of the lower side is generally pre-determined, you’ll need to calculate the appropriate slope for the roof. Roof slope is the quantity of inches a steel roof ascends vertically for each 12 inches of horizontal length. Although they can be more steeply pitched, a lot of single sloped building roofs employ one-half on twelve pitches. Strip malls, office suite areas, as well as mini-storages often employ the single slope engineering.
Think carefully about how your building will be used, and talk to your qualified steel building manufacturer or supplier to determine which building is the best selection for your project.

Utilization of Purlin Braces in Pre-Engineered, Pre-Fabricated Steel Buildings

admin — Sun, 23 Dec 2007 09:19:34 +0000

Adequate purlin bracing in pre-engineered steel buildings calls for substantial connections between the eave and ridge ends. A common building technique known as sag angle, or strapping in basic aligned rows, does not necessarily prevent breakdown and failure of purlin braces.
A correctly installed row of purlin bracing is anchored to the strong ridge angle or a channel at the ridge. In the case of a double-sloped rooftop, this helps impede the compression introduced by the accumulated energy of bracing. A sag angle placed along the ridge is not strong enough to do the job. �
Parallel bracing is generally attached to the eave strut in one of two manners. It can be accomplished by means of a direct connection or by crossing the purlin braces. Or, it can be attained with the use of sag angles between the initial purlin and the eave strut.
Purlin stability is not easily achieved by an exchange of the purlin brace with the eave strut’s bottommost flange due to the effect of torsional opposition on the eave strut. Instead, the strength of the purlin can be considerably fortified when a crossed brace is introduced as a compression member.
Superior design in�blocking placement�results in�the separation of the first “Z” purlin and then the eave struts, which can create great opposition to turning or twisting (torsion) and prevent lateral buckling.In certain circumstances, if an exceedingly wide all-steel building is being considered, the crossing method detailed earlier should also be affixed to the angle braces for given interior building bays. As long as they understand the design of the building, its use and local weather conditions, today’s steel building manufacturers can produce buildings with adequate support that last a long, long time.

A Review of Snow and Rain Loads Regarding Pre-Fabricated Steel Buildings

admin — Wed, 19 Dec 2007 09:12:14 +0000

For anyone planning to erect a steel building, a thorough knowledge of snow and rain loads is vital, particularly in the northern states. The maximum anticipated snow density on a structure’s roof at any one time is called the Design Snow Load. Live load is defined as the result of the occupancy of a pre-engineered building, while snow load computations are based on a precise location atop the building. The total snow load amount is calculated based on measurements taken at several locations on the roof. The estimated ground snow load total, the flat roof snow load are combined with the exposure and thermal amounts. Additionally, the roof pitch is input into the calculations. All of these factors work together in rather complex formula to determine the Design Snow Load “� but, believe it or not, there is even more to consider.� �

Wind energy works with evaporation to displace some building roof snow, causing the ground snow load figure to increase versus the roof snow load amount. Snow sliding and snow drift are additional common phenomena which must be accounted for. The design snow load on a lower building roof must be increased “� by as much as four times “� when another higher roof exists close enough to deposit sliding snow. Walls and parapets can experience considerable amounts of snow depth, so a greater snow load should be incorporated by considering the total square footage of the roof, parapet and wall elevations.

It is critical that the building engineer considers potential uneven amounts of snow atop either hip or gabled steel building roofs. Specific formulations for the given precise loading required for this design must include the total area involved, pitch of the roof, and the pitched and flat roof snow loading total.

Partial loading is another critical consideration involved in complete analysis of snow loading. Typically, the application of partial loading is specified in the design of structural supports like purlins or frames working with a multi-span configuration as opposed to clear span construction. Varying amounts of design snow load may be required among different areas of a building. Achieving correct snow load balancing requires careful planning.

Rain-on-snow and rain loads must also be factored into the calculations for proper roof loading. In certain areas of the country snow can abruptly turn to rain “� hence, the requirement for rain-on-snow load. If the steepness of a roof is minimal the added water can’t drain away readily and it is absorbed by the existing snow. The solution to this heavier load includes adjusting the roof pitch in a combination with roof bracing. “Rain load”� or total weight of rainfall becomes a factor in situations where roof rain drainage is ineffectual. The dependability of just about any pre-engineered structure can be improved by verifying ideal rain drainage from the steel roof. Potential rooftop failure from rain load may be circumvented by using exterior rather than inner conduits.
As you can see, determining the correct roof load design is a very complicated matter, but one that can be successfully navigated with the help of resources available through your qualified steel building manufacturer.

The Benefits of a Steel Roof

admin — Sat, 15 Dec 2007 09:12:44 +0000

Selecting a steel roof to top your new building provides more advantages than just keeping the wind and rain out. The roof can improve the appearance of the building, and a building that looks good is more likely to attract business. Steel roofs can be designed to match the aesthetic beauty of the rest of a building, as they are available in a vast assortment of shapes and finishes. Quality does not have to be sacrificed for appearance “� there is more than meets the eye involved in roofing design. Read on to learn more about the various types of steel roofs that can provide just what you need and the look you want.�

Like the rest of the steel building, steel roofs have a reputation for being highly efficient and water proof. In fact, recent innovations have improved the entire building system. They continue to require very little maintenance over the life of the building and they may even come with a guarantee from either the manufacturer or the supplier. The end result is a roof that can last for decades and protect not only your “stuff”� but, more importantly, keep your people comfortable as well.�

Obviously, a roof’s main function is to keep water out, and a steel roof is no different. A steel roof that facilitates water-shedding will have a minimum pitch of “three on twelve”� and still be able to maintain that great look. When a steel roof is built to be water-tight, it is able to handle “water-ponding.”� This type of roof design is called “hydrostatic.”� Minimally pitched styles are frequently used in waterproof roofs, mainly because a flat roof allows water to collect and possibly leak inside. It is possible to create the look of a flat roof that is actually pitched. This is done by embedding the roof below the top of the walls so that it is out of sight and yet is still able to shed and drain water when necessary. However, even waterproof roofs cannot prevent leaks at certain key locations such as eaves, ridges, and rakes “� regardless of what the pitch is. In order for a roof to be classified as waterproof, the pitch needs to be at least “one on twelve.”� When the rainfall average for a given area is high, the pitch is usually steeper to allow for faster drainage.�

“Structural roofing”� is another type of waterproof design. Even without assistance from decking, structural roofing can span the distance between widely spaced roof purlins. While structural roofing works best with steeper inclines, it works effectively with more gradual inclines, too.�

“Roof decking”� is another type of steel roof. This type of roof is able to sustain a construction worker’s weight of 250 lbs. and comply with certain wind uplift requirements. Roof decking, or closely spaced sub-purlins, provides the rooftop support to any nonstructural or architectural roofing. An architectural roof is very comparable to that of a water-shedding roof in that they both perform the same function, but it also offers its own aesthetic value. Although severely pitched roofs are feasible with this type of roofing design, considerable structural reinforcement plus superior sealant quality is necessary. The bottom line is that you can have a roof on your new building that not only looks great, but also keeps you warm and dry inside”�if you build it with steel.

The Steel Framework Reliability of Pre-Fabricated, Pre-Engineered Steel Buildings

admin — Sat, 15 Dec 2007 09:12:43 +0000

What makes a pre-engineered steel building structurally sound To answer this question, you need to understand how its components and framework work with the support system. Depending on the building length, the conventional single floor all-steel building system is comprised of main frames that incorporate various bays. Unless otherwise specified, the size of the bays is ordinarily 20 or 25 feet. The given distance separated by frame centerlines along the sidewalls is the actual bay size in the structure. Any barrier-free expanse between the framework supports contains the wide-span frame system, which measures the width of the steel building. An auxiliary building component called a purlin traverses from main frame to main frame. The steel roof panels provide a weather-tight interior envelope, and the purlins handle the building structural loads.

Pre-engineered steel building systems can require several wall components, and high-grade metal siding models continue to be the reigning preference. The building sidewall and/or endwall utilize girts that reinforce the high-grade steel siding. Building endwalls are constructed with endwall supports which act as reinforcement elements for the girts and are put at pre-designated distances based on the blueprint template to maximize the bracing efficiency of the girts. The building endwall columns reinforce building roof beams seated from column to column, which is also called post and beam supporting framing.

Structural frames that support the building exterior walls and steel frames that stretch across the width of the structure are commonly found in steel building configurations. Level building loads usually run in a direction parallel to the structural frames and can be addressed via straight-up structural bracing throughout the building endwalls. Sidewall reinforcement withstands vertically coursed building loads.

The lateral stability of a pre-engineered steel building is vital to the integrity of the structure. Any pre-engineered, pre-fabricated steel building assembled without sideways support will not long withstand Mother Nature’s forces. A rigid frame is the best metal framework to sustain lateral stability in a steel building. While there are other framework configurations on the market, make sure that they contain enough horizontal stiffness to ensure the stability of the completed building. X-bracing, or braced frames, can also furnish more horizontal strength. This upright buttressing is not only capable of contending with lateral building loads, but will also help sustain the overall rigidity of the steel building. The configuration of shear walls can also supplement perpendicular rigidity.

If the initial building plans include preparation for eventual expansion, a regular main frame should be employed as opposed to structural endwall framing. This is because structural endwall supports are generally only intended to supply up-and-down and lateral girt buttressing. With proper advance planning, extending the building is a pretty simple process: remove the endwall, insert the extra roof, wall panels and bays, and finally reconnect of the original endwall. Normally, no new endwall is required. The popularity of metal structures continues to grow thanks to all of the design and technical improvements that have become standard as the industry has matured.

Utilization of Purlin Braces in Pre-Engineered, Pre-Fabricated Steel Buildings

admin — Tue, 11 Dec 2007 09:13:10 +0000

To ensure sufficient purlin bracing in steel buildings, multiple connections are required between the eave and ridge ends. A common building technique, sag angle, or strapping in basic aligned rows, will not automatically prevent breakdown and failure of purlin braces.

A row of purlin bracing should be anchored to the strong ridge angle or a channel at the ridge. For a double-sloped rooftop, this assists with reducing the compression introduced by the accumulated energy of bracing. It is not satisfactory to just place a sag angle along the ridge.

Parallel bracing is generally attached to the eave strut in one of two manners, either by means of a direct connection or through crossing the purlin braces. It can also be accomplished through the use of sag angles between the initial purlin and the eave strut.

Purlin stability is not easily achieved by a transfer of the purlin brace with the eave strut’s bottommost flange, due to the broad difference of the torsional opposition for the eave strut. If a crossed brace is included, it can considerably improve the reliability of the given purlin.

Superior design in�blocking placement�is achieved by the separation of the first “Z” purlin and then the eave struts. The application of blocking can provide great resistance to turning or twisting (torsion) as well as lateral buckling. �

In the case of an exceedingly wide all-steel building, the crossing method detailed above may also have to be attached to the angle braces of interior building bays to provide additional support.

Regarding sideways purlin bracing, a common assumption is that the eave strut is stationary and therefore an excellent location for attachment. However, the eave strut will indeed have movement, and may not provide much horizontal support for either the roof sheathing or purlins. But if the siding is connected with tightly patterned fasteners, eave struts can supply substantial torsional reinforcement for the purlins. Conversely, they provide only minimal support if purlin movements force screws to loosen or the eave strut is not even connected to the wall of a structure.

Another effective bracing scheme is the use of crosswise designed steel angles separating the top flange of one purlin from the bottom flange of the adjacent purlin. Crosswise purlin braces permit each purlin to form one side of a triangle, of which the remaining two sides are comprised of the roof and the crossways brace. This bracing technique is restricted to configurations using through-fastened rooftops; it does not work for standing-seam applications. This scheme is only viable if the rooftop has the ability to oppose compressive forces and is securely attached to the purlins.

Just like parallel purlin bracing, the diagonal brace method is heavily reliant on the use of ridge channels or angles to enable it withstand the numerous strains arising from a set of rooftop inclines. The structural soundness of any steel structure is greatly improved when the correct purlin bracing method is applied.

Most Pre-Fabricated, Pre-Engineered Steel Structures Aren’t Equivalent

admin — Fri, 07 Dec 2007 09:13:37 +0000

You may have studied a great deal of building information recently if you are contemplating an all-steel building purchase. Perhaps you saw commercials on television, searched the Internet, or heard advertisements on the radio. Many ads pronounce, “The lowest priced steel structures available! Take advantage of these hot deals! Act now!”� What is being offered: quality steel structures or cheap substitutes

Very reputable steel structure manufacturers and suppliers certainly do offer high grade, all-steel structures that are fairly priced “� frequently at a fraction of the price of a traditional building. But, generally speaking, the structures advertised as “economy”� or “budget”� buildings are often constructed with low caliber, lightweight 29 gauge steel. Particularly if the building will be used as accommodations for people, low caliber steel is substandard. Structures built with 29 gauge or greater steel frequently suffer maintenance problems. Quality steel systems are built of durable 26 gauge steel “� accept no less.

Quonset huts are the product of outdated methods. Basically, the faulty structure and the heating and cooling costs over the serviceable life of the Quonset hut can transform this “low cost”� structure into a very pricey acquisition. The additional expenses required to adequately insulate the Quonset to control energy costs can be exorbitant, resulting in a total price that is way more than most owners want to spend “� and no where near the initially offered “great deal”� for the basic building. �

The process of selecting the appropriate building system could be compared to undergoing a necessary medical procedure. Would you choose the most inexpensive surgeon or one who will complete the operation successfully and in a professional manner In other words, the old adage, “you get what you pay for,”� applies in either situation.
If your preference is to ensure the long term success of your building project, engage the best steel structure manufacturer you can afford. One company guides you from design to final rigging of the building, with no supplementary “brokering”� expenses. Consider only premium quality materials, and although these manufacturers may not propose the cheapest price, they will offer the best available price to guarantee the best possible results. There is no need to deal with different suppliers for various construction phases, enabling you to ensure timely scheduling of deliveries and a smoother process from beginning to end.

Skill to Decide on the Proper Pre-Engineered, Pre-Fabricated Steel Structure Manufacturer

admin — Mon, 03 Dec 2007 09:14:04 +0000

There are a number of factors to consider before choosing the steel building manufacturer for your project. Besides searching on the Web or simply picking the company closest to you, consider these aspects before you make your final, best choice.

When searching on the Internet for the words “steel building,”� some people consider only steel structure firms that are highly rated. However, companies that are returned at the top of the list indicate that their Web sites are more frequently visited. The information on their home page should be recent, informative and helpful. Steel companies should clearly state how they can maximize your cost savings as opposed to conventional building methods. Other facts that should be readily apparent are the length of the guarantee and the caliber of the steel used. Remember, the lower the gauge number, the heavier the steel is. For practically any building application, 26 gauge high-grade steel is the recommended caliber.

New steel structure systems are just about maintenance free, due to the fundamental quality and durability of commercial grade steel. The steel building you choose should be manufactured to meet or exceed current local building ordinances, and be able to withstand the weather and elements in your area. Building systems advertised as “on sale”� or “on the dock”� very likely do not meet these requirements. �

The steel building producer that you select should provide an experienced engineering design team, and the company should be able to fabricate to your needs no matter how complex your design specifications are. Be sure that the design team has at least several years of planning experience.

Almost any steel structure manufacturer insists that they offer the best value. Understand that a truly good value includes galvanized purlins and girts, as well as extended weather secure PBR (purlin bearing rib) pre-engineered roof sections. Be sure that delivery charges are included, and not buried in the contract as extra hidden costs.

Favor truss-less technology in order to maximize the total allowable clear-span (internal support free) space. This is essential if you desire an obstacle-free environment, for such uses as an event center, riding arena or warehouse.

To ensure that you are really getting the best price for the features offered, take the extra step to compare “apples to apples”� among steel companies. By shopping around and asking some key questions, you’re sure to find the best steel building company for your building investment.

Minimizing Risk Together With Pre-Engineered Steel Structure Construction

admin — Thu, 29 Nov 2007 09:15:15 +0000

Before beginning a steel building project, it is very important to review government regulated safety procedures, as well as to thoroughly understand local building codes. These guidelines should be followed throughout all construction phases.

Minimizing risk is a key factor in any successful project. Individuals at the construction site should be instructed on safety procedures including any Occupational Safety and Health Administration rules. As inexperienced personnel are brought into the project, be sure to thoroughly review the accident prevention procedures with each of them. Safety instruction should be an ongoing process. �

The assembly site should be inspected for overhanging barriers such as power lines. All digging should be pre-approved by local utility companies. All power tools should be in good working order and grounded. �

Apparel such as gloves, hardhats, shoes with rubber soles, and protection for the eyes should be mandatory. Equipment and tools should be of premium quality.

When moving large components like rafters, be sure that the lifting apparatus has no damaged or frayed cables. No persons should ever be under a load maneuver, nor should they ever come in contact with a moving load.

Always adjoin the mainframes to girts and purlins before proceeding to the next bay during steel building assembly. Never leave the project site unless frames are supported or braced. At the construction site main, structural framing must never be cut or altered. Without exception, install wind buttressing exactly as the drawings denote.

Insulation materials should never be allowed to get wet. Anyone working with or near structural insulation should be protected with dust masks, gloves, and long-sleeved shirts. Do not allow anyone to walk on insulation materials, nor should anything be placed on or against them. �

When working on steel roofing, the work force should be constantly be aware of where the edge is. In order to be safe enough to walk on, pre-engineered roofing sections must be coupled to the purlins and abutting panels. Skylights should never be walked upon. Any of the steel building roof pieces not properly anchored should only be accessed by properly positioned planks.

The above rules are the minimum required suggestions to secure a successful completion of your construction project. For these and other safety considerations, ask your pre-engineered steel building supplier or manufacturer, or refer to your steel building construction manual.

Other Alternative Purlin Schemes Regarding Pre-Engineered and Pre-Fabricated Steel Buildings

admin — Thu, 29 Nov 2007 09:15:04 +0000

There are several styles of purlins that work well for steel structures. It’s important to understand each one in all their intricacies. We’ll discuss a couple of them below. �

Many systems use hot-rolled steel beams. The growth in pre-fabricated, pre-engineered steel buildings occurred a number of years after the introduction of hot rolled steel purlins. In the early 1900s, building roof frameworks were manufactured of trusses spanned with hot-rolled channel and I-beam purlins. Even today, for applications requiring substantial internal reinforcement, this approach is still utilized. The growing popularity of hot-rolled steel beams as compared with lighter gauged designs is due to their large load-bearing ability. Hot-rolled beams are especially favored when traverses exceed 30 feet. They can also support substantial overhead loads from within the interior. Although this option is super strong, it can be very expensive. �

Braced or unbraced hot-rolled steel purlins are easily adjustable for uplift, whereas “Z”� and “C”� cold-formed framing are not readily adaptable to this force.

A wide flanges and channels design creates hot-rolled steel structure roof purlins. A combination of hot-rolled purlins and steel decking results in optimum reinforcement and can span long distances. It is less costly to install these above the primary frame rafters. The particular purlins’ spacing is established by the desired load carrying ability of the steel deck. A roof-deck diaphragm or sag rod bracing can be employed to supplement the purlins to deal with building stresses. Sag rods can be installed up to three inches below the topmost part of the steel, which lowers torsional strain.

Another purlin style uses open-web steel joists. Steel building systems that span more then 30 feet as well as buildings that require wider bays are best-suited for open web joists. Also called bar joists, they can reach larger areas than cold-formed or hot-rolled purlins.

A standing-seam rooftop can be easily attached to a still buildings when open-web joists are used, and cable or horizontal rod bracing increases diaphragm effectiveness. One drawback to bar joists, unfortunately, is their inability to withstand substantial torsion burdens, as there are no solid webs to aid in transfer of this stress.

There are a couple of dependable engineering techniques to support standing-seam pre-engineered steel roofing that use bar joists. One way is to install a steel deck and add thin gauge hat channels over the deck and upright to its flutes. Another is to include closely spaced cross bridging instead of incorporating the steel deck into the configuration. The stability is controlled by the cross bridging along the compact intervals, allowing the complete assembly to withstand any energy forces.
Choosing the correct purlin option requires that you and your qualified steel building engineer take into account the building design and all of the potential stresses and forces that will act upon it.