New Mexico Administrative Code
Title 14 - HOUSING AND CONSTRUCTION
Chapter 7 - BUILDING CODES GENERAL
Part 4 - 2021 NEW MEXICO EARTHEN BUILDING MATERIALS CODE
Section 14.7.4.16 - ATTACHMENTS AND CONNECTIONS

A. General. Attachment and connection methods of alternate wall construction to rammed earth walls are described as follows. The building official may approve other attachment and connection methods. In no case shall two wall types be butted to each other without consideration for attachment or connection.

B. Attachment of a rammed earth wall to a rammed earth wall. A keyway, at least six inches wide by three inches deep shall be formed vertically at the center of the wall section from stem top to underside of bond beam. The connecting wall shall be rammed into the keyway. (Refer to Figure 3 of the earthen building figures supplement).

C. Attachment of a load-bearing adobe wall to a rammed earth wall. Where adobe is deployed as an interior wall that will be incorporated into the rammed earth wall for lateral support, the adobe shall measure a minimum of 10 inches in thickness. Steel ladder reinforcement shall be rammed into the wall at the intersection with the adobe wall. The reinforcement may be bent against the forms during the ramming process. After ramming is complete and forms removed, the reinforcement shall be incorporated into the adjoining adobe coursing, every four courses minimum. (Refer to Figure 12 of the earthen building figures supplement). As an alternative, a keyway, not to exceed the depth of the adobe wall, nor one-third the depth of the rammed earth wall, shall be formed into the rammed earth wall. The adobe shall be incorporated into the keyway. (Refer to Figure 13 of the earthen building figures supplement).

D. Attachment of a loadbearing wood or steel frame wall to a rammed earth wall. A half-inch minimum diameter anchor bolt with four inch hook, set in a linear vertical pattern, a maximum of 24 inches on-center. The anchor bolt shall be embedded at least two inches into the earth wall with the threaded end protruding sufficiently to pass through and attach the adjoining vertical wall stud. The washer and nut shall be tightened just prior to sheathing the frame wall. As an alternative, 18 gauge by two inch minimum galvanized strap tie, grouted into the concrete bond beam (or secured to the wood bond beam or wood top plate), securely nailed to the top plate of the frame wall. The remainder of the vertical stud shall be attached to the rammed earth wall with 30D nails or screws embedded a minimum of three inches into the adjacent wall at eight inches on center vertically. (Refer to Figure 14 of the earthen building figures supplement).

E. Attachment of a door or window unit to a rammed earth wall. The unit shall be attached to nailers within the opening or nailed or screwed directly into the rammed earth wall. The nail or screw shall penetrate at least three inches into the rammed earth wall. Heavier units may utilize stronger attachments, such as anchor bolts, T-bolts, steel pins, etc., embedded into the rammed earth wall.

F. Attachment of foam or rigid insulation to a rammed earth wall. Insulating boards or foams not exceeding two inches in thickness may be adhered to the exterior of the rammed earth wall. When insulation board is used, round-cap nails, capped concrete nails or capped screws shall attach it to the rammed earth wall . Cap nails or screws shall have a maximum spacing of 16 inches from each other. Additionally, cap nails or screws shall secure the insulation boards around their perimeter edges with nails or screws spaced no less than two inches apart. All cap nails or screws shall penetrate a minimum of two inches into the rammed earth wall. All insulation fasteners shall be corrosion resistant. Insulating boards or foams shall not be used to form architectural shapes exceeding two inches in thickness.

G. Attachment of cabinetry to a rammed earth wall. Deck screws shall penetrate a minimum of three inches through cabinetry and into a nailer, eight inches on center maximum, or; deck screws with a least three inch minimum penetration through cabinetry and into the rammed earth wall. Screws shall be placed horizontally, eight inches on center maximum, on the top and bottom of cabinetry. As an alternative, all-thread rods or other attachment devices, suitable for attachment of cabinetry through the rammed earth wall.

H. Attachment of concrete bond beam to a rammed earth wall. Number four reinforcing bar shall be driven into the uncured wall top. The reinforcing bar shall be set at a maximum 20 degree angle along both edges of the wall, staggered no more than 24 inches on-center and no closer than four inches from the exterior faces of the wall. The reinforcing bar shall extend a minimum of two inches into the rammed earth wall and four inches into the concrete bond beam. (Refer to Figure 16 of the earthen building figures supplement).

I. Attachment of wood bond beam to a rammed earth wall. One-half inch anchor bolts with four inch base hooks shall be rammed into the wall. The bolts shall be staggered a maximum of 48 inches on-center along both edges of the wall, staggered no closer than six inches from the exterior faces of the wall. The bolt shall extend a minimum of 18 inches into the rammed earth wall.