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7 <br /> DCF Englneenng, Inc. <br /> Cadwalader Jones Law Office September Page 2 of 5 <br /> dry laid stone wall of the law office was parged, the timber floor of the office was <br /> removed and replaced with a concrete slab, and the wall was tied into the slab with <br /> anchors at the floor line. <br /> STRUCTURAL REQUIREMENTS: <br /> The primary structural system consists of brick walls and a timber roof structure. <br /> These appear adequate to resist forces imposed by wind and snow loads as required <br /> by code. The critical condition is lateral earth pressure and hydrostatic pressure which <br /> has caused the foundation wall to bow outward, taking the south wall of the building <br /> with it. <br /> DISCUSSION: <br /> yAlthough the wall may appear to be stable at this time, the cement parging will <br /> continue to crack as moisture passes through it. To repair the bow in the brick wall <br /> will require some masonry restoration, shoring and bracing, and underpinning. If it is <br /> desired to install a wood floor to replace the existing concrete slab on grade inside the <br /> building then the stone foundation wall should be reinforced or rebuilt because the <br /> floor slab is now acting as an anchor. <br /> Replacement of th e slab w ill r equ ire that an alternate method of tieing back the stone <br /> wall be installed. There are at least three solutions which will stabilize or correct the <br /> bow in the south wall. The wall can be tied back with earth anchors of several <br /> different types. Sufficient attachment to the stone wall will require an array of many <br /> anchors or some kind of grillage of steel to be set against the face of the wall. <br /> Alternately, the wall can be replaced with a reinforced concrete wall faced with a <br /> veneer made from the existing stones. <br /> tThe best solution would be to rebuild the wall using traditional stone wall <br /> construction. A new wall, concrete or stone, will have to bear on firm subsoils below <br /> the frost line. The enclosed sketch shows the dimensions for a dry laid stone gravity <br /> wall which will be a stable, permanent solution. The most difficult part of dealing <br /> with this construction is the temporary support of the building while the underpinning <br /> is accomplished. <br /> A traditional dry laid stone wall will last forever if properly built. Proportions of the <br /> wall, soil bearing conditions, and drainage will affect its service life. The temptation <br /> to place concrete behind it, point the joints with mortar, set the stones in mortar, or <br /> parge the wall should be resisted. The wall will have to turn the corners of the <br /> building and also retain the entrance platform. As the wall runs uphill, it should be <br /> stepped as needed to prevent it from slipping down the slope. <br />