Figure 8-7. - Braoe rods.
Sag rods are used to hold the purlins and the girts in a straight line. First, install the sag rods that connect the two purlins at the ridge of the building. Each rod must be attached from the' top hole of one purlin through the bottom hole of the adjacent purlin. Use two nuts at each end of the sag rods-one on each side of each purlin. Adjust the nuts on these rods, so the purlins are held straight and rigid.
Next, install the sag rods between the purlins below the ridge with the rod attached from the top hole of the upper purlin through the bottom hole of the lower purlin. Use two nuts on each end-one on each side of each purlin. Follow the same procedure with the sidewall sag rods.
Remember that the roof purlins should show a straight line from end to end of the building. Do NOT tighten the sag rods so much that the purlins are twisted out of shape.
After two or more bays have been erected, part of the erection crew can be assigned to install the diagonal brace angles.
To install the brace angles, lay the notched portion against the frame flange and bend it into position (fig. 8-8). Diagonal brace angles are needed to support the inner flange of the frame. Be sure to install them so that they are taut.
While some members of the crew are installing brace angles, other members can be installing base angles. When assigned this duty, first, sweep off the top of the concrete foundation, so the base angles will set down evenly. Bolt the base angles in place with a flat steel washer under the nut. Leave the nuts loose to permit later adjustments after the wall sheeting has been applied.
Refer to the manufacturers' specifications for proper assembly and installation procedures for end-wall framing, doors (both sliding and roll-up), andContinue Reading