The use of quality interior framing is very important to the integrity of today’s steel buildings and their support. However, the proper selection of the correct endwall framing is also key for maximum serviceable life and expandability issues.
            The structure of most endwall framing in any steel building is very similar. Correct endwall framing is responsible for resisting any loads applied to the two endwalls and to properly support the wall girts. A standard interior frame is introduced at the top of the walls for those steel buildings engineered with expandable endwalls. The interior frame deflects all lateral loads that are acting on the sidewalls along with any vertical loads present. The endwall farming’s responsibility, in this scenario, is merely to support the wall girts. For those building not utilizing expandable endwalls, endwall framing should incorporate X-bracing to support any vertical loads.
             Endwall framing is essentially made up of vertical columns, roof beams, and corner columns, all of which have base plates and other necessary components. Typically, the endwall columns consist of either single or double cold-formed channels with a minimum steel thickness of fourteen gauge. Unless future expansion of the building is planned, the end rafters are generally made of cold-formed channels. Rafter design is comprised of single-span members which are spliced at the column. The most common spacing for endwall columns is twenty feet on center. This measurement is closely allied with best engineered plan of span of the girts’ supporting abilities. Normally, the column configuration will begin from a center column at the ridge line. However, if there is no center column used the two endwall columns will be introduced into the ridge line.
            A coupling between an endwall column and a rafter may be achieved by the bolting of the rafter web to the column flange and connection of the purlin to the rafter by means of a clip angle. This can only be done if the endwall is non-expandable. A second option is to have the column couple with the rafter by implementing endwall connection channels. Whichever method is applied, a rake angle is required at the purlin top in order to properly support the wall siding.
            The procedure for endwalls that are expandable is the introduction of another bracket angle between the column and frame rafter and also between the frame column and the endwall girt.
            A bypass inset is used with endwall girts. These are fashioned as single-span components framing and introduced into the webs of the endwall column. Bypass girt design is as a continuous member. They may also be attached to the columns or the sidewall girts at the structure’s corners with brackets.
            Thos structures utilizing concrete, masonry, or glass walls may see a wall structure that extends sharply from roof to foundation. The entire endwall framing structure, in this scheme, may only entail the use of a clear-span rigid frame. This is very much like the buildings that use expandable endwalls but without the need for columns or endwall girts.