SIGNS OF STRUCTURAL DISTRESS Often the biggest indicator of a possible serious structural problem, a crack indicates symptoms of movement, some of which are of no structural consequence. Expansion and contraction cracks are caused by G changes in temperature and humidity. A stepped crack indicates a differential settlement of H the soil or foundation support.
THE STRUCTURE
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YOUR HOME REVEALED
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he adage “out of sight, out of mind” could not be more applicable than when it comes to understanding the structure of a home. In most Brooklyn homes, this system is composed of a masonry foundation (below ground) and wood framework (above ground). The walls separating two rowhouses is known as a “party wall.” These walls are composed of two or more wythes (horizontal layers) of brick for stability and fire enclosure. In narrow rowhouses (usually 16’ wide or less), the party walls support the weight of floors and the roof. Wider rowhouses have internal load-bearing walls that are supported by piers at the foundation. In some homes, the framework has brick infill to provide some measure of fire protection and does not serve a structural purpose.
W A L L A B O U T H O M E O W N E R ’ S P R E S E R VAT I O N M A N U A L
A straight crack across a plaster ceiling perpendicular I to the direction of floor structure indicates that the joists have deflected or sagged. Horizontal cracks at mid-height level indicate a weak J foundation wall. Sagging can be caused by a loss of stiffness in a K structural member, such as a pitched roof. A floor that slopes to one side can indicate differential L soil settlement or the deflection of inadequately sized supports in the basement, causing the whole side of the house to move downwards. The M
front or rear masonry wall may tilt forward or bulge outward noticeably over time due to settling or pressure from an adjacent house. Water infiltration can compromise the connection of a wood floor joist to the exterior wall, causing the wall to bulge.