AFI announces a return to their roots...

Advanced Forensics & Inspections, LLC is pleased to announce that as of Spring 2019, we will be focusing exclusively on the inspection and analysis of the Building Envelope. As Managing Director this represents a “return to my roots” as a Building Envelope Specialist. I look forward to leading AFI with dedication in the type of work I enjoy most, in a specialized field where I believe we can be of the greatest service to our clients.

What is the Building Envelope?

According to Wikipedia: “A building envelope is the physical separator between the conditioned and unconditioned environment of a building including the resistance to air, water, heat, light, and noise transfer.“ https://en.wikipedia.org/wiki/Building_envelope

…or as I like to put it simply, “We help keep the weather on the outside.”

With over 18 years experience in this particular field of architectural engineering, in different climates across more than a dozen States, I believe that AFI can offer an unprecedented level of expertise to property owners, particularly in the residential space. We will continue to be based in Denver, CO and offer our services all along the Front Range, while serving our commercial accounts nationwide.

We appreciate the continued support of of customers and clients. Our success is predicated on fulfilling your needs and we are grateful that you have chosen us to help provide “Quality Assurance for Your Greatest Assets.”

-Chris Perrotta

The Problem with Aluminum Wiring

Between approximately 1965 and 1973, single-strand (solid) aluminum wiring was sometimes substituted for copper branch-circuit wiring in residential electrical systems  due to the sudden escalating price of copper. After a decade of use by homeowners and electricians, inherent weaknesses were discovered in the metal that lead to its disuse as a branch wiring material. Aluminum will become defective faster than copper due to certain qualities inherent in the metal. Neglected connections in outlets, switches and light fixtures containing aluminum wiring become increasingly dangerous over time. Poor connections cause wiring to overheat, creating a potential fire hazard. In addition, the presence of single-strand aluminum wiring may void a home’s insurance policies. We always advise our clients to speak with their insurance agents about whether the presence of aluminum wiring in their home is a hazard, a defect, and a problem that requires changes to their policy language.

The solid aluminum wiring shown above represents a potential fire hazard. 

Why is Aluminum a Problem?

Aluminum possesses certain qualities that, compared with copper, make it an undesirable material as an electrical conductor. These qualities all lead to loose connections, where fire hazards become likely. These qualities are as follows:

• It has higher electrical resistance: Aluminum has a high resistance to electrical current flow, which means that, given the same amperage, aluminum conductors must be of a larger diameter than would be required by copper conductors.
• It is less ductile: Aluminum will fatigue and break down more readily when subjected to bending and other forms of abuse than copper, which is more ductile. Fatigue will cause the wire to break down internally and will increasingly resist electrical current, leading to a buildup of excessive heat.
• Galvanic corrosion:  In the presence of moisture, aluminum will undergo galvanic corrosion when it comes into contact with certain dissimilar metals.
• Oxidation. Exposure to oxygen in the air causes deterioration to the outer surface of the wire. This process is called oxidation. Aluminum wire is more easily oxidized than copper wire, and the compound formed by this process – aluminum oxide – is less conductive than copper oxide. As time passes, oxidation can deteriorate connections and present a fire hazard.  
• Greater malleability: Aluminum is soft and malleable, meaning it is highly sensitive to compression. After a screw has been over-tightened on aluminum wiring, for instance, the wire will continue to deform or “flow” even after the tightening has ceased. This deformation will create a loose connection and increase electrical resistance in that location.
• It experiences greater thermal expansion and contraction: Even more than copper, aluminum expands and contracts with changes in temperature. Over time, this process will cause connections between the wire and the device to degrade. For this reason, aluminum wires should never be inserted into the “stab,” “bayonet” or “push-in” type terminations found on the back of many light switches and outlets.
• It experiences excessive vibration: Electrical current vibrates as it passes through wiring. This vibration is more extreme in aluminum than it is in copper, and, as time passes, it can cause connections to loosen.

What are the Options for Correction?

Aluminum wiring should be evaluated by a qualified electrician who is experienced in evaluating and correcting aluminum wiring problems. Not all licensed electricians are properly trained to deal with defective aluminum wiring. The U.S. Consumer Product Safety Commission (CPSC) recommends the following two methods for correction for aluminum wiring:

• Rewire the home with copper wire: While this is the most effective method, rewiring is expensive and impractical, in most cases.
• Use copalum crimps: The crimp connector repair consists of attaching a piece of copper wire to the existing aluminum wire branch circuit with a specially designed metal sleeve and powered crimping tool. This special connector can be properly installed only with the matching AMP tool. An insulating sleeve is placed around the crimp connector to complete the repair. Although effective, they are expensive (typically around $50 per outlet, switch or light fixture).

Although not recommended by the CPSC as methods of permanent repair for defective aluminum wiring, the following methods may be considered:

• Application of anti-oxidant paste: This method can be used for wires that are multi-stranded or wires that are too large to be effectively crimped.
• Pigtailing: This method involves attaching a short piece of copper wire to the aluminum wire with a twist-on connector. the copper wire is connected to the switch, wall outlet or other termination device. This method is only effective if the connections between the aluminum wires and the copper pigtails are extremely reliable. Pigtailing with some types of connectors, even though Underwriters Laboratories might presently list them for the application, can lead to increasing the hazard. Also, beware that pigtailing will increase the number of connections, all of which must be maintained. Aluminum Wiring Repair (AWR), Inc., of Aurora, Colorado, advises that pigtailing can be useful as a temporary repair or in isolated applications, such as the installation of a ceiling fan.
• CO/ALR connections. According to the CPSC, these devices cannot be used for all parts of the wiring system, such as ceiling-mounted light fixtures or permanently wired appliances and, as such, CO/ALR connections cannot constitute a complete repair. Also, according to AWR, these connections often loosen over time.
• Alumiconn: Although AWR believes this method may be an effective temporary fix, they are wary that it has little history, and that they are larger than copper crimps and are often incorrectly applied. 

In summary, aluminum wiring can be a fire hazard due to inherent qualities of the metal. AFI inspects the electrical panel(s) during every property inspection and can alert you to such a  potentially unsafe condition.

January is National Radon Action Month

As designated by the EPA, January is National Radon Action Month. The intent of this program is to raise awareness about the serious, yet preventable, health risks associated with Radon exposure.

What is Radon?

Radon is a naturally occurring radioactive gas which is a byproduct in the decay chain of uranium. This odorless, colorless gas can seep from the ground and collect in enclosed spaces or water supplies. Due to a short half-life of only ~3.8 days, it breaks down quickly and deposits a trail of harmful radioactive particles in its wake. The Alpha-wave radiation from these particles cannot penetrate our skin or even a sheet of paper, so in general we are safe from it, unless we breathe it into our lungs or ingest it into our bodies through water. This is why Radon is so dangerous, as prolonged breathing of Radon gas allows these harmful elements to enter our bodies and long-term exposure has been proven to cause lung cancer.

Due to the substantial amount of uranium present in the soil in Colorado, the majority of our state is rated Zone 1 – the highest threat level by the EPA. Radon is measured in picoCuries per liter (pCi/L) and the EPA recommends mitigation for levels above 4/0 pCi/l. Along the Front Range, it is not uncommon to see readings well above this level. Last year, one older multi-family property in Westminster tested at 47pCi/l in the seemingly well-ventilated basement apartment, more than 10x above the “Dangerous” level. The only way to detect Radon is to specifically test for it.

If you smoke, or spend time in an enclosed smoke-filled environment, the threat level can be greatly magnified as particulate in the air contributes to the ingestion of even more of the radioactive decay particles. 

What Can You do About Radon?

Fortunately, Radon is generally easy to remove from a structure, through a process called mitigation. Radon mitigation contractors can utilize a series of equipment and techniques to seal a home and vent radon away into the outside air. The method of radon mitigation is well understood and this type of work is regulated, with contractors that are required to be trained, certified and in many states, licensed.  Radon can be present in commercial buildings as well as homes, in both new and old structures.

Not All Tests Are The Same

The presence of Radon can be tested in several ways, typically over a period of at least 48 hours. We strongly recommend a radon test be performed during the purchasing process of any property and following the installation or repair of a Radon Mitigation system. Radon can be tested for in a number of ways, but when there may exist a conflict of interest, care must be taken to ensure the test is not invalidated by someone accidentally (or intentionally) altering the results. Common events which can affect accurate testing include opening windows (altering the typical enclosed conditions of a space) or in particularly unscrupulous cases, moving the testing equipment outdoors and returning it to the inside before the inspector retrieves the testing equipment.

Due to the seriousness of this health threat, at AFI we use only state-of-the-art, WIFI-enabled lab-connected Radalink AirCat™ testing meters which are routinely calibrated in a strictly controlled environment. These devices monitor not only Radon, but humidity, air flow and any actual movement of the meter itself. This is the only way to ensure accurate sampling in an uncontrolled environment. We believe that a serious life-safety concern such as Radon requires nothing less than the best protections the industry has to offer.

In the Denver metro area, a Radon mitigation system for a typical single-family home generally costs around $900-1400 and is a common condition of sale. Older homes with crawlspaces or larger properties may require additional methods and equipment, at increased cost.

Schedule a Radon Inspection from AFI during National Radon Action Month (January 2018) and receive $25 off the cost of your test!  Please enter code "RADON2018" on your request.

If you have questions related to radon, feel free to comment below, give us a call or drop us an email. Additional information about Radon can be found here:

EPA (download) “Protocols for Radon and Radon Decay Product Measurements in Homes”

Colorado Department of Public Health & Environment – Radon

Boulder County Radon Health Risks

The Winter Solstice & Quarterly Home Maintenance

Despite our famed “300 days of Sunshine,” and 70-degree days in the middle of December, Colorado does have four seasons marked by the Solstices and Equinoxes. These quarterly divisions at the change of seasons provide us with the perfect calendar reminder for some simple home maintenance.

     1. Check your fire extinguishers: You have them, as in several... right? After years of inspecting properties, it still comes as a surprise the sheer number of occupied homes we enter each year that do not have a single working fire extinguisher! At a minimum, we recommend one per level of the home plus one additional unit each in the kitchen and furnace/utility room.  Kitchen units should be rated "K" for grease and oil fires and the one in your furnace room should be rated "C" for electrical fires, or better yet "ABC" for multi-purpose fires. Ensure each unit is properly charged by checking the gauge – the needle should be in the green zone.  Some of the more expensive larger units can be “recharged” but smaller, single use units may need to be replaced. (Pro Tip: Fill out the tag or sticker when you inspect your unit, it serves as a good reminder for you but also demonstrates a standard of care to an observant home inspector!) 

This handy chart courtesy of OSHA.gov shows the type and recommended purpose for each type of extinguisher.

Check your local laws regarding disposal of expired extinguishers, which still may be under pressure and present a disposal hazard. In some jurisdictions they can be turned in to your local fire department or taken in on special “hazardous waste recycling” days.

     2. Change your furnace filters: Manufacturer recommendations vary, but every three months is a good rule of thumb for a replacement schedule. Clogged filters can lead to decreased indoor air quality and introduce strain on your HVAC system. The filter is the least expensive component in your furnace and can have a profound effect on performance and service life.

Help your furnace run more efficiently by regularly changing the furnace filter.

     3. Check your alarms – Smoke, CO2 and Water: These devices may be hard-wired into the electrical system, tied into the home automation/alarm system or simply be stand alone units powered by batteries. (The last category is the most susceptible to unknown malfunction.) Don’t have a water alarm or even know what one is? You aren’t alone – check out our previous blog post about these devices and be sure add one to your shopping list.

Some guidelines recommend replacing all batteries quarterly; in a practical sense this might be overkill but these are life-saving devices so we’ll let you make that call. At a minimum, we recommend checking them quarterly and replacing all batteries annually.

     4. Check your Radon mitigation system:  If you live in Colorado, you likely have one of these systems installed at your home. (If you don’t, contact us for a tamper-evident Radon test today, as our state is one of the worst locations in the country for Radon and you might be at risk.) Radon systems will have a liquid filled tube (hydrometer) on the exhaust pipe which indicates proper vacuum – meaning airflow is being pulled by the fan to the exterior.

The exhaust pipe on your radon mitigation system should have a hydrometer on it, similar to the one pictured above, which indicates vacuum.  

The fans in these systems, typically located on the exterior of the home, have a serviceable life of about 5 years. If your hydrometer does not indicate that your system is venting to the exterior contact a radon mitigation company ASAP to have your system repaired.

Four quick steps for the four seasons… we will revisit this idea again in 3 months!

From everyone at AFI, we wish you a happy, healthy and safe holiday season! 

Is Your Attic Properly Insulated?

When is the last time you poked your head up in the attic? Maybe you were retrieving holiday decorations, or storing your summer clothes up there? Chances are if you are like most homeowners, we tend not to think about attic insulation until we notice a problem.  Now is a good time of year to take a peek up there and make sure your insulation is in good shape.

Why insulate?

The insulation in your attic is like a thick hat on your head while you are out in the snow – it can make all the difference between being freezing cold or sufficiently warm. Heat rises and in doing so, it can escape your home, requiring you to turn the furnace up.  This effect is generally well-understood here in Colorado and isn’t typically a concern with newer construction.  Older homes however may have substandard insulation which can lead increased energy costs and strain on the HVAC system.

In an insulated attic, we typically see several inches of fiberglass batt insulation (the pink stuff) or blown-in cellulose (off-white and fluffy) or mineral wool (yellow to grey dense fiber) but do you have enough? In order to make that determination first we need to understand R-Value.

R-Value is the capacity of an insulating material to resist heat flow. The higher the R-value, the greater the insulating power.

Hint: If your insulation is only as high as the joists, it's probably insufficent!

Insulation requirements in Colorado?

Fortunately for us, are several organizations which provide guidance as to the right amount of attic insulation. We prefer to go right to the top with the U.S. Department of Energy (DOE) and the International Energy Conservation Code (IECC), which designates Colorado as a complicated mix of Zone 5, Zone 6 and Zone 7 which varies by County. This is simplified somewhat, as all three zones have the same recommendation for an attic space: R49-R60.

R-value per inch varies between insulation types as well as from manufacturer to manufacturer, but the general guideline from the DOE for the common types of residential insulation is as follows:

Insulation Type:                R-Value per Inch:

Fiberglass (loose)             2.2 – 2.9

Fiberglass (batts)             2.9 – 3.8

Cellulose (loose)               3.1 – 3.8

Stone Wool (loose)          2.2 – 3.3

Stone Wool (batts)          3.3 – 4.2

Cotton (batts)                  3.0 – 3.7

What does all this mean? Well, in Denver, working with an average R-value of 3/inch the general rule of thumb is that you should see 14+” of insulation. Many folks we have spoken with seem to think that “14 inches of insulation is Code” which isn’t necessarily the case. As demonstrated above, there are several variables at play here so be sure to ask your inspector for help in determining if the insulation in your attic is sufficient.

Stay warm and enjoy the holiday season!

Understanding the Freeze-Thaw Cycle

Today in Denver, the temperature is expected to reach a high of 53°F during the day, with a low of 24°F at night. That is a 29°F temperature change within less than a 24-hour period, across the point of freezing (32°F) – or what some might call a typical Fall day here in Colorado.

The recorded temperatures in Denver from last week - look at those temperature swings!

It seems to perfect time of year to discuss the phenomena known as the Freeze-Thaw Cycle. The science behind the freeze-thaw cycle is fairly simple. When water freezes it undergoes volumetric expansion; it increases approximately 10x in size during the process of changing from liquid to solid. When liquid water is allowed to seep into the cracks and crevices of a surface, (particularly hard, porous surfaces such as concrete, asphalt and masonry) and then freezes, it exerts tremendous forces which results in cracking and spalling. In certain climates this back-and-forth daily cycle of melting ice/snow during the day followed by that retained moisture freezing at night can lead to substantial damage in short order.

You may have heard of the freeze-thaw cycle in relation to roadway damage, but what many people don’t realize is that the freeze-thaw cycle can also have damaging effects on the exterior of your property. Here are a few things you can do to limit the damage of this cycle:

     1.      Remove standing snow from upward facing surfaces. Our climate is typically dry enough that removing the snow promptly from sidewalks, patios and driveways will allow them to dry within a day, thus limiting the volume of water penetrating into these surfaces. Other areas to think about include the trim, shelves and ledges on the walls around your property. Masonry windowsills are particularly vulnerable. Fortunately, it isn’t too difficult to sweep these areas clear so that they have a chance to dry out before the overnight freeze. Wooden windowsills and ledges should be painted and sealed routinely prior to winter. When possible, consider cladding such surfaces in aluminum.

     2.      Limit the exposure of susceptible surfaces to water. There is a reason why our forebears designed homes with long roof overhangs. Consider our climate and exposure during new construction and incorporate these elements wherever possible. Awnings and carports (when structurally sound enough to support snow loads) not only make clearing off the car easier, but can protect a driveway. Keeping vegetation off of masonry walls can help limit water from wicking into these surfaces and promote faster drying. 

     3.      If exposure cannot be limited, consider sealing the surface with a specifically-designed masonry sealer. It is easy to think of  hard surfaces as watertight, but in-fact concrete, masonry, and brick are quite porous and can absorb a substantial volume of water. There are several products specifically designed to penetrate and seal these surfaces – and “exterior paint” is not one of them! Painting masonry can actually cause more problems than leaving the surface untreated, so be sure to read the manufacturer’s recommendations thoroughly and use the right product for the right material.

The freeze-thaw cycle - it’s the reason many locals say, “Colorado has two seasons winter, and roadwork.” Just remember that it’s not only our roadways subjected to this problem.

(A little tip for those of you within Denver City proper, you can report potholes and other issues here: https://denvergov.org/pocketgov/#/report-a-problem)

The $15 Box That Can Avert Disaster

Last Thursday I awoke abruptly to the sound of a loud alarm going off in my home. I sat up and my mind quickly raced through possible scenarios – Fire? No, not the right tone. Carbon monoxide? No, that sounds like the smoke alarm… Radon samplers? No, they are all out in customer’s homes right now. Wait, water?!? Yes, WATER!

I ran down to my basement utility closet and discovered a backup quickly rising from the central floor drain. The water alarm positioned on the floor at the base of my water heater detected the backup and had alerted me with enough time to prevent an irritating problem from becoming a potential disaster. (As it turned out, I was about to experience an ordeal regarding a broken sewer line, but at least the fetid water was confined to a small concrete area within the house!)

Circled in this photo, is the star of our story, a water-sensing alarm. This was positioned by the water heater and boiler (furnace) as a precaution, but in this case, it detected a sewer back-up from the floor drain. 

This little box circled above is a water-sensing alarm and over the years, it has become a standard recommendation during our residential home inspections. This device is similar to a smoke alarm, but instead of smoke, when it senses water it sounds a piercing tone. This can alert an occupant of a water problem, often before it becomes an outright flood. Water heaters (the subject of a future post…) are prone to leaking with age. As they are often located in dusty utility closet or tucked in the back corner of a basement, leaky units can go undetected for a long period of time. This can lead to all sorts of problems, such as drywall damage, mold, even health concerns from thirsty pets coming to investigate.

We recommend protecting your home by placing one of these water sensing alarms on the floor in your utility closet and/or near your water heater. They are carried at the major big-box hardware stores but sometimes can be hard to find on the shelves. Sometimes they can be found stocked near the smoke alarms, which makes sense, but more often I’ve found them tucked way back in the far a corner of the plumbing section. They typically cost under $15 including a single 9v battery. 

This is a popular model which features a detachable, wired probe in the base, permitting the meter to be installed at a convenient height above the floor.  (Specific model depicted for illustration purposes only, AFI is not affiliated with Glentronics, Inc.)

There is an old expression which I am fond of: “The shoemaker’s children run barefoot.” I have always interpreted that to mean that we often don’t follow our own advice, or make use of the skills which we share with others, for ourselves. I’ve been recommending water alarms to my clients for years, and I am grateful that I followed my own advice!

7 Ways to Care for Your Home This Fall

Ah, October in Colorado... That first burst of cold that comes along with the changing of the leaves. In the Denver area we typically see rain early in the month, often giving way towards our first snow of the season. With this time of year comes several things which we recommend as basic care and maintenance for your home.

1. Clean the Gutters…  Yes, you have heard this before and you will hear it again here. Your gutter system is an essential for diverting water away from the foundation. Before the bulk of the leaves fall is a great time to ensure your gutters are draining properly. Use care while working on ladders and roofs, as these surfaces tend to be slippery when wet. If you are uncomfortable working at heights, consider using a gutter cleaning service. The small fees for this are negligible compared to the potential water damage which often result from improper drainage.

A properly functioning gutter set-up. 

2. Check the Sealant Joints at Windows and Doors. The sealant (sometimes in this context improperly referred to as “caulk”) around your windows and doors fulfills a critical role in keeping your home dry. Most sealants require a minimum of 24 hours at a temperature over 40°F to cure properly, so now is likely the last opportunity apply these products before the onset of winter. We recommend homeowners take a quick walk around the house to observe the tiny joints surrounding windows and doors. Sealant should be repaired or replaced wherever gaps are noted. As a general rule, latex, silicone and polyurethane sealants are not compatible with one another. Cut out a piece of the sealant to take to the store and ask someone if you are not sure what type you have. Be sure to read the manufacturer’s instructions on the product tube and always use the right sealant when making spot repairs.

Even small gaps in sealant joints can permit substantial amounts of water to enter a home, particularly when snow sits up against them and then eventually melts. 

3. Drain and Cover the Hose Spigots. All external hose spigots (sometimes referred to as bibs or faucets) should be drained and the interior valves leading to these spigots closed whenever possible. Failure to drain an exterior spigot can cause water trapped in the supply pipe to freeze and then burst, often leading to major water damage within the walls and interior of the home. Here in Colorado where we experience rapid temperature changes within short periods of time, we highly recommend the installation of freeze-resistant spigots. Lastly, install faucet protectors to help keep ice and debris out of your exterior spigots.

Inexpensive, reusable faucet protectors and can help protect your exterior spigots from freezing, but they are not a substitute for draining the lines!

4. Test the Furnace, Before You Need It!  Check your filter(s) and replace them if needed. Start the system up on a cooler day to ensure it is working before you really need it. If the system requires service, it’s best to know early when you can schedule the repair in advance.  Anyone who has tried to get an HVAC contractor out in the middle of winter can attest to the additional cost and headache. If you have not had the furnace serviced in the recent years (or just don’t know when it was serviced last) consider taking advantage of one of the many “Winterization Specials” offered by local HVAC contractors at this time of year. Furnaces are expensive to replace and often system failure results from simple neglect.

Routine furnace service will save you money and ensure your home is comfortable in the middle of winter. 

 5. Say Goodbye to the AC. Now is the time to remove any window AC units and check the window frames for damage. Exterior AC condensers should have the fins cleaned out and then be covered to prevent ice and debris from entering the unit. However, make sure your exterior condenser is just that – an AC unit – never cover a heat pump! If you have an evaporative (swamp) cooler, don’t neglect to drain the unit and then install the winter filters and cover the unit in accordance with the manufacturer’s recommendations. If you are not sure what kind of system you have or what needs to be done, ask your home inspector or check with an HVAC contractor.

Exterior condenser units like this should be cleaned and then covered during the winter months.

6. Have the Fireplace Inspected and the Chimney Cleaned. Creosote buildup in chimneys results in over 20,000 home fires within the US each year. If you have a fireplace, contact a chimney sweep to have it cleaned and inspected before using it. Ensure that gas-fired fireplaces have the flame jets properly adjusted in order to reduce carbon build-up and ensure efficiency.

Only a clean and properly functioning fireplace is a safe fireplace.  

 7. Seal the Garage Door & Jambs. Prevent substantial cold air infiltration by ensuring that your garage door is seated properly to the garage floor. Observe the gasket along the bottom and make sure it is slightly compressed against the ground while the door is closed. Inspect the bottom of the jambs (sides of the door frame) for rot, as this is a damage-prone area can allow the unwanted entry of air, water, insects or even wildlife.

Garage door jambs are particularly susceptible to moisture damage. 

These 7 preventative care items can typically be accomplished within an afternoon or contracted through an appropriate professional services company for reasonable rates. In the long run, it is much more cost effective to perform routine maintenance before winter hits.

From all of us at AFI, have a wonderful Fall!

Crimes of Water Penetration....

We thought that we might start out with a bit about our company name - Advanced Forensics & Inspections, LLC. Inevitably while at a networking event, particularly one where alcohol is served, a question about the word forensics comes up – usually followed by someone making this sound:

Many people think solely of crime scenes when they hear the word forensics, but Miriam Webster poses several definitions, including:

Belonging to, used in, or suitable to courts of judicature or to public discussion and debate;
Relating to or dealing with the application of scientific knowledge to legal problems

Forensics as it is commonly applied to building science denotes the use of a specific methodology to arrive at a conclusion which is previously unknown. The findings of our forensic investigations are all too often are used to settle litigation matters and our expertise has been called on by several courts for dispositions and testimony as an Expert Witness. That answers the question about forensics, but what specifically is  Building Envelope Forensics?

Building Envelope Forensics is the science of analyzing buildings to determine the cause of air/vapor infiltration and water penetration within the “building envelope” – those components which wrap the building to keep the elements out.  

Everything you see here and more, is considered part of the building envelope.

Sometimes problems are relatively easy for us to diagnose, such as a home where the gutters are missing, causing a leak in the basement. The building equivalent of a minor street crime, which wouldn’t even make it onto an episode of your favorite crime drama…

Most homes have gutters for a reason!

Other times the “crime” is complex and difficult to figure out. On one investigation, we diagnosed a home where water was leaking in through the live electrical box for the chandelier in the center of the dining room ceiling, repeatedly damaging the very expensive wood table and flooring below it. This water would sometimes appear to trickle in after a long stretch of days without rain, but sometimes also in substantial volume immediately during a rainstorm.

To solve that case, we used many tools from our detective kit: taking statements from the suspects (i.e. the home’s occupants, roofing and siding contractors), studying the crime scene (i.e. the house) under various conditions, looking for the fingerprints of water penetration with moisture probes, wet wall scanners, thermal IR imaging cameras and borescopes.

Police detectives study criminal psychology and know that cracking a complex criminal case often involves understanding the moves and motives of several persons. We study building science and we know that the cause of a water penetration in a home is typically a result of a series of failures between different systems. Understanding how these systems work together is often the key to solving a puzzle.

After some solid field work, we were able to determine that the leak was caused by poor workmanship during the replacement of the siding over a year prior. It was believed that workers pulled the second-story dryer vent out too forcefully, causing a separation in an elbow of duct work, which happened to be in close proximity to the electrical box for the chandelier. With four children in the home, laundry was a regular occurrence and a typical residential dryer can pump as much as 1 gal. of water (as vapor) out of a single 8lb. load of laundry! This moisture collected withinin the insulation between the trusses, and eventually condensation collected on the cool surface of the metal electrical box. There was the cause of water when it wasn’t raining, but what about the sporadic deluge when it did rain?

We found that the dryer vent was not set flush into the siding nor was it properly flashed (sealed) to the exterior sheathing. In the event of wind-driven rain from the southeast side of the property (which was uncommon for how this house was situated) where the vent was located, rain was forced in and quickly and traveled along the already damp space between the trusses by cohesion -  the property of water molecules that allows it to stick to things and contributes to water flowing more freely over wet surfaces.

The ceiling was opened and the vent elbow was re-attached and sealed. The mold between the trusses mitigated and the insulation was replaced. Finally, the dryer vent was properly reset with the penetration properly flashed in to the sheathing.

Case Closed! 

While interior mold and water damage is certainly less gruesome than a chalk-line body on the floor, we take our forensic work no less seriously when it comes to solving water problems at your property.

Feel free to make the "Dun Dun" sound as we conduct our investigation.   

Hello!

Hello and welcome to our new website including this blog for Advanced Forensics & Inspections, LLC (AFI)! This blog will contain brief, regular posts with stories, tips and advice for both residential and commercial property owners.

We hope that you find it interesting, educational, entertaining & worthwhile.  

Thank you for reading!