Forensic Engineers and Consultants

Archive: Construction Defects

Moisture Intrusion into Structural Reinforced Concrete

Scenario:  The owners of Jones’ Marine, a marina with a wharf structure on a tidal saltwater river, cater to the operators of ships, barges, and large yachts.  There are both diesel and gasoline fuel pumps at the edge of the wharf.  In addition, a large mobile crane for lifting the large vessels out of the water for maintenance is in service at the wharf.  This crane is driven out to the edge of the wharf deck suspended over the water, subjecting this deck and the structure beneath it to very high loading.  They purchased the property from its former owners about 10 years ago and are conscientious about maintenance and upkeep of their thriving facility.  They decide it is time to have a survey performed of the condition of the precast reinforced concrete piles and pile caps beneath and supporting the concrete wharf platform/deck.  They are alarmed at what is discovered by this survey:  Significant spalling Read More

WARREN WEBINAR: “Issues with Breaching the Building Envelope”

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LIVE WEBINAR:
10/5/21  @ 1 pm EST “Issues with Breaching the Building Envelope” | Presented by George Sanford, P.E., Senior Consulting Structural Engineer

COURSE LEARNING OBJECTIVES

In this Webinar, we will discuss water entry through a variety of building envelope breaches. Water entry and subsequent wood decay, fungal growth and structural damages as a result from water intrusion can lead to serious property damage and major expenses for all types of property owners. We will discuss the definition of a building envelope, and look at various case studies involving breaches to the major components of the envelope. These major components include foundations, exterior walls, and roofs. The foundation case studies include issues with slabs-on-grade, crawlspaces, and basements. The exterior wall case studies involve improperly installed building wrap, leaking windows, and problems with stucco. The roof case studies look at issues with various roof coverings, vents, and penetrations. Participants will take away a thorough understanding of what defines the building envelope, how breaches to the envelope can occur, and how to identify root causes. Read More

Lack of HVAC System Design and Poor Installation Lead to Extreme Conditions

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Construction defects can appear in many forms.  The building does not necessarily have to fall down. There are many types of construction defects, including roof leaks, water intrusion into walls, as well as Heating, Ventilation, and Air Conditioning (HVAC) defects.

One extreme example of this was an office complex I was called to for an investigation of the source of mold observed on the walls.  The occupants complained that they could not find a temperature setting on the thermostat where they could make the office comfortable. When I inspected the office, I couldn’t believe what I was seeing.  A band of black mold Read More

Moisture Intrusion into Concrete Slabs-on-Grade

Scenario:  A young couple is excited about buying their first home.  They pick it out from a catalog of house plans from the developer of a new neighborhood in town.  It will be a brand new construction starter type bungalow home on a slab-on-grade foundation.  For a cost adder, which is considerable to them, they decide to upgrade the finished flooring from carpeting to hardwood laminate.  Unfortunately, after only a few weeks of residency, the hardwood planks begin to buckle and separate from the slab throughout the house.  They do not know what is causing it, or what to do to remedy it, Read More

Issues with Moisture Intrusion through Flashing into Wood-Framed Structures

Flashing is a hot-button topic amongst residential designers, builders, and claims adjusters alike. In fact, currently one of the most prominent construction defect claims that we see involves moisture intrusion around improperly flashed window openings in wood-framed structures. Other trouble spots include the roof penetrations at chimneys and vent pipes. Read More

Installation of Structural Sheathing on Wood-Framed Structures

The facts presented in this blog lead to an interesting story.  During the heyday of the residential construction boom in coastal South Carolina circa 2005, many General Contractors were forced to go out-of-state to find framers and other subcontractors due to the demand creating a local labor shortage.  It turned out that the state of Texas had excess capacity and availability of framers and carpenters. Many Texas framing crews came to South Carolina to satisfy the shortage.  It soon became apparent that the Texas crews, many of which were from inland locations, were accustomed to installing 4’x8’ exterior wall sheathing with the long dimension vertical, i.e., parallel to the studs.  It is especially important and required that the long dimension be oriented perpendicular to the studs.  Laboratory testing has shown that Read More

Types of and Techniques for Reinforced Concrete Masonry Block Construction

Construction using concrete masonry blocks or units (CMU) is ubiquitous in the United States today, and in fact in the whole modern world.  CMU blockwork is a very versatile and relatively economical building material.  It is naturally strong in compression, but with reinforced, grout-filled cells, it can also withstand large shear, bending, and tensile loads imparted by lateral wind or seismic events.  In this article, I will discuss the various types of CMU designs, as well as terminology, construction techniques, and application uses.

The design of CMU is typically comprised of hollow concrete “face shells” with Read More

Uplift and Shear Restraint Techniques for Residential Structures in Hurricane Wind Zones

Hurricane and Tropical Storm strength wind forces can wreak havoc on wood-framed residential structures.  One of the primary hazards is the negative pressures which can develop on the exterior building envelope when the structure is subjected to the high encircling winds.  These negative pressures act like the suction of a giant vacuum on a dwelling’s roof diaphragm, which produces enormous uplift forces throughout the entire structure.  The leeward walls are also subjected to negative pressures, while the windward walls take the brunt of the positive wind pressures.  The uplift on the roof is caused by what the author dubs “the airplane wing effect”.  In other words, Read More

Structural Issues with Coastal Residential Foundations

From corrosion to site drainage, coastal regions present a host of unique and challenging issues for homebuilders and residential property owners alike.  In this article, issues specific to coastal residential foundation installation and in-service function will be addressed.  “Coastal residential” will refer to single-family homes within AE or VE tidal flood zones for the purposes herein.  These locations typically exist in areas with close proximity to saltmarsh or beachfront, or on barrier sea islands.  Per FEMA, in AE zones, the elevation of the first finished floor must be above the flood elevation for the building site.  In VE zones, the elevation of the lowest horizontal structural member must be above the flood elevation for the site.  Most building jurisdictions also require a minimum of (1) foot of freeboard, or additional space, between the flood elevation and these building features.  As a result of these requirements, coastal residential structures must be supported by either crawl-space or elevated “drive-under” style foundations.  It should be noted that wall-type foundations are prohibited in VE zones, and structures within these zones are required to be supported by monolithic elements such as columns, piers, or piles.  Slab-on-grade type foundations are not permitted in flood zones where the foundation will exist within the flood plain. Read More

Warren Welcomes George Sanford, Structural Engineer

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Warren is pleased to announce that George Sanford, P.E. has joined our team as an engineer specializing in structural issues, building envelope performance, and construction defect investigations.

George brings over 20 years of applied structural engineering experience with a strong background in residential, commercial, and industrial structural design to Warren. Read More

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