1.3 Basic System Concepts

8/2/2019 1.3 Basic System Concepts

1/16

Product ApplicationsBasic System Concepts

1.3 Basic System Concepts.doc 06.16.09 Page 1 of 16

Introduction:

ABOUT THIS MANUAL

The purpose of this manual is to acquaint you with the basics of metal building systemterminology and products of the building system industry in general. Furthermore, it isdesigned to familiarize you with VP Building systems in particular and to give you thebasic knowledge. If you already have a good working knowledge of these items thismanual should serve as an excellent refresher course.


2/16

Product ApplicationsBasic System Concepts


Basic Terminology

Basic metal building systems typicallyhave four outside walls. Two of thesewalls are located where the roof meetsthe walls in a line parallel to the groundwithout any increase in the height ofthese walls. The other two walls show arising line where the walls meet the roofand the height of the wall changes.

The line where the sidewalls meet theroof is called the eave line or eave. It

often has trim to enhance appearanceor gutter for removal of rain water fromthe roof. The distance from the bottomof the base plate to the point where theroof meets the wall, or the eave, iscalled the eave height, measured atthe back side of the wall panels andunderside of roof panels.

Eave

HeightEave or

Eave Line

Gable

Ridge or PeakThe line where the endwall meets theroof is finished with a piece of trim knownas rake fascia. The line where thesidewall s meet the endwall s is usuallyfinished out with a piece of trim known asthe corner trim. The peak receives a

plastic or metal cap know as a peak cap.The peak cap includes the VP logo.


3/16

Product Applications

Basic System Concepts


The roof pitch or slope is usually shownas 1-in-12, 1/2-in-12, and 4-in-12 etc.When inches are used as the basic unit,for example 2-in-12 roof pitch meansthat the roof that rises vertically 2 inchesfor every 12 inches measuredhorizontally.

Length

Width

Eave

Height

VP building systems have three basicdimensions: width, length, and eaveheight. The width is the distance fromthe outside of the sidewall girt on oneside to the outside of the sidewall girton the other side. The length is thedistance from the outside of the outsideof the endwall girt to the outside of theendwall girt on the other end. Eave

height is the distance from the Finish

Floor to the point where the roof meets

the wall.

VP buildings are dimensioned fromthe outside edge of the girt, to theoutside edge of the girt. The outsideedge of the girt is known as thebuilding line.

Building Line Building LineEave

Height


4/16




Systems & Components

VP building systems are built on top ofa foundation. The foundation isgenerally a concrete slab with concretefootings. The footing is extra concrete,usually rectangular in shape, pouredand formed under a column or someother structural support member of thebuilding. A footing distributes the loadcarried by the VP building systemsupport members into the supporting

soil. Anchor bolts are set in the footingto "anchor" the column or structuralmembers.

A pre-punched metal plate is welded tothe base of the column or structural tofit over the anchor bolts.


5/16




Primary Structural Support Systems

Clear Span

Modular

Primary structural support systemsfurnish the main support of a building.The primary structural support systemsare more often called the main framingsystem and can be divided into two basictypes, modular (Continuous Beam -

CB) and clear span (Rigid Frame - RF).Modular frames have one or more interiorcolumns between the exterior columns,supporting some of the vertical load

carried by the frame.

On modular frames, Continuous Beams(CB) and Continuous Trusses (CT), thedimensions between interior columns aremeasured from the outside of the sidewallgirt to the centerline of the first interior

column. On all other interior columns thecolumn spacing dimension is measuredfrom the centerline of one column to thecenterline of the next column until the lastinterior column is reached. The columnspacing on the last interior column isagain measured centerline of column tothe outside of the sidewall girt.

Interior column spacing may vary.

BL

BL CL

CL

ColumnSpacing

ColumnSpacing

ColumnSpacing

CL


6/16




Solid Web Primary Frames

Open Web Primary Frames

The rigid frame is probably the most

commonly used clear span frame. Clearspan frames have no interior columns orvertical support between the exteriorcolumns. The rigid frame has as astandard tapered vertical columns and atapered rafter section. A cross-sectionthrough either a column or rafter sectionwould show an I-shape. Typically, therigid frame is deepest in the knee orhaunch area where the column isconnected to the rafter beam.

Rigid FrameFlange

Web

Welds

Rigid Frame Truss (Wind Bent)

The Rigid Frame Truss (RFT or WindBent) is another type of clear span frame.The RFT has tapered exterior columns,

but unlike the rigid frame, the web of thetruss beam has open area. The RFTrafter is made up of angles welded in aspecially designed pattern between theflanges.


7/16




Bay Spacing

Frames are placed in a pattern toprovide the primary support for thebuilding, the distance between thecenterline of each frame is called a Bay.

Bay

BayCL

CL

CL

LC

CL BL

Spacing for the End Frame is measuredfrom the building (girt) line to thecenterline of the End Frame.

CL

Bay Spacing


8/16




Endwall Frames

End Frames

InteriorFrames

When a frame is located onthe interior of the building, it

is called an interior frame.When a frame is at anendwall, it is called anEndwall Frame or End frame.

Rake Beam

End Posts

Corner Post Corner Post

End Posts

The most common endwall frame iscalled a Post and Beam. Post andBeam frames are comprised of CornerPosts, End Posts and Rake Beams.They are designed to support half a bayof roof.


9/16




Secondary Structural Support Systems

Purlins Purlins

The principal segments of the roofsecondary support system spanningfrom frame line ot frame line are knownas purlins. The purlins transfer roofloads to the primary structural supportsystem, which in turn transfers the loadsto the foundation.

Continuous Purlins at Interior Frame

VP building system purlins come in avariety of material thickness anddepths. VP offers two basic types ofpurlins: simple and continuous. Thebasic structural shapes used in VPbuilding systems are 7", 8 1/2", 10,and 11 1/2" deep.

Continuous purlins overlap at framelines making the connection stronger.The continuous purlin overlap, whichcan vary according to conditions, oftenallows the use of a lighter gage (i.e.,more economical) purlin, saving thecustomer money while providing betterstructural integrity.

Simple purlins provide lap connectionfor alignment only. It is not a structurallap.


10/16




Eave Strut

A C channel use as purlin, known as

an eave strut, is located at the buildingeaves. Steep slopes (>4:12) will useadditional new solution with a fieldattached gage angle.


11/16




Truss Purlin (TP)Truss purlins (TP) are economical for use when bay spacing exceeds the limits ofstandard purlins. Span range for use of truss purlins are typically 11 to 60 feet.Overall depths are from: 18 to 40 in 2 increments with a standard 5 seat depth. Themembers will bolt to the primary frames using pre-punched holes and bolts. Themembers are lighter than traditional bar joists and easier to erect.

A foating roof system (SSR or SLR) must be used with trus purlins; a screw down roof(Panel Rib) is not permitted.

Standard WideBay members are stopped short of the frame centerline. Non-strutmembers have 9/16 x 7/8 slots in the seats and are connected with (2) 1/2" A325bolts (49080) with hardened washers.


12/16





13/16




Girts

Girts

In the wall areas, attached to thecolumns, are 7", 8 , 10, or 11 1/2"Zee or Cee shaped members - similarto the purlins on the roof. These arethe principal segments of the wallsecondary support framing system andare called girts. The girts take theloads imposed on the covering systemand transfer them to the frames, whichin turn transfer them to the foundation.

The spacing of VP girts, like thematerial thickness of girts, varies withthe load imposed on them. VP offerstwo basic girt connections -continuous and simple.

The most econmical girt systemfurnished by VP Buildings iscontinuous outset girt.

The advantage of inset girts is anincrease usable space inside thebuilding at the column location for thesame size building.It should be remembered that bydefinition, the building width ismeasured from outside of sidewallgirt to outside of sidewall girt.Therefore, when using the insetgirt condition the building frames

are moving out into the girt line.

The building does not get wider.


14/16




Diagonal Bracing

Portal Brace:

Portal FrameEave

Floor

Wind exerts a force on all buildings.One of the primary design featuresused to resist this force is bracing.Bracing consists of sets of rods in theroof, between the rafters, and in thewalls, between the columns.

The specific design criteria (wind andseismic) that will govern a particularbuilding will determine the quantityand location of bracing rods. Bracingrods are often called "X" rods, windbracing, roof rods, wall rods, or "X"bracing.

Other Bracing options are discussedin the Wind Bracing section.


15/16




Covering Systems

VP Buildings offers a variety of covering systems available for both the roof and wallsto match an owner's needs and budget. The gauge, finish, configuration, width, andfastening systems can all vary.

Primary Wall Panel Types

Panel Rib Vee Rib Stran Loc

Reverse Roll Panel Rib

Primary Roof Panel Types

Standing Seam Panel Rib


16/16




SLR

Other components such as insulation, trim and accessories will be discussedlater in this manual.

Basic System Tips

It is usually most economical to make leastdimension the width.Gablebuildings usually more economicalthan single-sloped buildings.

Date post:	05-Apr-2018
Category:	Documents
Upload:	mohammad-touffique
View:	215 times
Download:	0 times

1.3 Basic System Concepts

Documents