Elevated relative humidity and moisture from condensation and roof leaks can cause damage to other construction materials or items that are stored in the attic. An understanding of the building envelope, relative humidity, and the dew point are helpful in identifying attic ventilation problems.

The building envelope is a physical barrier that separates the interior environment from the exterior environment. The roof, attic, and ceiling are the building envelope for the top of the house. The roof separates the exterior environmental elements of wind, rain, snow, hail, other loads, and ultraviolet rays from the interior environment of the house. The attic space, attic insulation, and the ceiling, separate the temperature and humidity of the exterior environment from the interior environment. Another way to describe these environmental barriers is to refer to the roof as the building envelope and the insulated attic floor as the thermal envelope.

Relative humidity is the ratio of how much water vapor is contained in the air at a given temperature relative to the amount of water vapor required to saturate the air at that temperature. Relative humidity in the attic is commonly measured with a humidity meter. The amount of water vapor that can be contained in air varies with the air temperature, which is why the humidity is referred to as “relative”. Water vapor condenses at a relative humidity of 100%. The dew point temperature in air is the temperature that water vapor condenses.

Warm, moist air, which leaks into the attic from the living area below, can raise the relative humidity in the attic to a level that promotes mold growth. If the warm, moist air in the attic comes in contact with attic surfaces, which have been cooled to the dew point temperature by colder outside temperatures, condensation will form on the attic surfaces. The condensation can damage the surfaces on which it forms and on surfaces on which it drips. If the warm, moist air in the attic comes in contact with attic surfaces, which are at, or below the freezing temperature of 32 degrees Fahrenheit (32° F), frost will form on the surfaces. When the temperature of the attic surfaces rise above 32° F, the frost will melt, and can damage items that are wetted by the dripping moisture.

Damaging levels of relative humidity, condensation, and frost, can be avoided in the attic by eliminating roof leaks, reducing the amount of warm, moist air that migrates into the attic from the interior of the house, and by ventilating the attic to exhaust the warm, moist air to the outside. Numerous moisture sources are present inside the house that can leak into the attic. A list of moisture sources and their estimated moisture output are listed in an article, which is located at this Oregon State University website.

Proper attic ventilation is achieved by the use of static air vents, or by the use of the proper combination of static vents and power ventilators. A common static ventilation system has soffit vents and roof vents. The roof vents are located on, or near the ridge of the roof. A power ventilating system has soffit vents and one or more power ventilators (fans), which are located near the ridge of the roof. Both types of ventilation systems operate on the principle of drawing outside air into the attic from the low vents, and exhausting the air through the high vents. Static roof vents are not used high on the roof in combination with power ventilators because the power ventilators will draw air from the high roof vents rather than the soffit vents, which reduces the air flow from the soffit vents to the roof ridge vents. This ventilation problem is known as “short circuited” ventilation.

Ten common attic ventilation problems are shown in the following figures. Recognizing these problems is helpful in diagnosing the cause of an attic ventilation problem.

Figure 1: A common ventilation problem is the improper retrofitting of new soffit vents over the original soffit vents. Improper retrofitting of soffit vents can reduce the net ventilation area to less than the required amount.	Figure 2: The net ventilation area of roof soffit vents in older houses may be partially obstructed by debris and multiple coats of house paint.

Figure 3: Roof soffit vents can be obstructed if they are covered with attic insulation. Rafter baffles are commonly used to hold back the insulation from the edge of the roof eave to maintain an unobstructed airway for the soffit vent.	Figure 4: An exhaust duct for a bathroom exhaust fan should be vented to the outside. If the exhaust duct is terminated in the attic, warm, moist air is vented into the attic, which can increase the relative humidity in the attic to damaging levels.

Figure 5: Debris on this static roof ventilator, as viewed from inside the attic, restricts the proper air flow through the ventilator.	Figure 6: This static roof ventilator, as viewed from inside the attic, was installed off-center of the opening in the roof sheathing, which reduces the net ventilation area of the ventilator.

Figure 7: Placing a power ventilator in the center of four static roof ventilators “short circuits” the attic ventilation, which can render the soffit vents inoperative and cause ventilation problems in the attic.

Figure 8: A power ventilator should have a dual control: a thermostat that turns on the fan when warm temperatures are detected in the attic, and a humidistat that turns on the fan when high levels of humidity are detected in the attic. A properly set thermostat will ensure that the power ventilator operates during the warm summer months, when the fan is needed to exhaust warm air from the attic. A properly set humidistat will ensure that the power ventilator operates during the cold winter months, to exhaust warm, humid air from the attic.

Figure 9: A vapor barrier is not installed between the ceiling drywall and the blown-in insulation. The required amount of net ventilation area in the attic is doubled if an approved vapor barrier is not installed between the drywall and the insulation.

Figure 10: The gap in the ceiling around this furnace flue pipe is a common location for warm, moist air from the furnace room to leak into the attic, which can increase the relative humidity in the attic to damaging levels. The discoloration in the insulation is caused by the flow of warm, moist air through the opening. All unnecessary gaps that are located around ceiling penetrations should be sealed when possible.

“Texas has been on our radar screen for a number of years, but we have intentionally delayed our efforts to open offices in this market,” says Kevin B. Abell, Donan Engineering’s chief sales and marketing officer.  “We saw a huge need for us to build up additional offices in surrounding states, which will now allow us to properly support our Texas market in the event of a catastrophic event that overextends our local capacity.  Our growth over the past couple of years has now allowed us to build up the level where we feel 100% confident in our ability to move into Texas as an industry leader from day one.  We see the opportunity to really improve the service levels our clients are used to receiving throughout the state.”

Abell went on to say, “At Donan, we live to serve our customers’ needs by providing industry-leading customer service and turnaround time on our assignments.  Our approach is to have more offices in closer proximity in order to provide more efficient response times to losses and more investigative personnel close by to provide any additional support needed.  We know that, as the saying goes, ‘Everything is bigger in Texas,’ including the expectations of our customers, so we are prepared to meet the challenge.”

Donan Engineering offers consumers a single source for forensic engineering investigations and fire origin & cause investigations.  The firm offers a wide array of services falling under the main categories of structural engineering investigations, fire and explosion origin & cause investigations, roofing investigations, and component testing.

Donan Engineering is a third-generation, family-owned engineering firm that was founded in 1947 in Madisonville, Kentucky.  From 1947 until 1999, the firm focused on providing mostly conventional engineering services (civil, structural, environmental, mining, architecture, etc.).  In 1999, with approximately 20 employees in four offices, the decision was made to focus exclusively on the forensic engineering and fire investigation industry.  In 2005, the firm relocated its company headquarters to Louisville, Kentucky.

With the addition of the new Texas offices, Donan Engineering will have 38 offices located throughout 19 states.  Currently, the firm retains approximately 210 employees, and that number is anticipated to grow to near 280 employees by the end of 2012.  In 2011, the firm completed approximately 27,000 forensic investigations for a client base consisting primarily of insurance companies, attorneys, commercial property owners and businesses, manufacturers, utilities, and homeowners.  For a list of Donan’s office locations, please visit www.donan.com/locations.

Is construction vibration just an annoyance, or does it have the potential to cause aesthetic and structural damage to nearby structures?

Ground vibration waves behave similarly to those that propagate when a stone is dropped into water.  Movement through the earth is generated vertically as well as horizontally.  As the waves travel away from the source, they encounter an increasingly large amount of material, which causes the energy in the wave to dissipate.  Therefore, the larger the distance between the source of the vibration and the object detecting the vibration, the weaker the effect.

The human body is an excellent detector of vibration, but a poor measuring device.  Most investigators have determined that the best way to measure the magnitude of vibration and the effect on human and building response is using peak particle velocity (PPV).[1] PPV is measured in inches per second (IPS), with a larger value representing a bigger vibration.  Some average measurements for daily activities in a house are:  walking – 0.29 IPS, nail hammering – 0.55 IPS, door slamming – 0.59 IPS, and jumping – 2.19 IPS.  Research shows that the human body can notice PPV as little as 0.02 IPS, which is far below the activities previously mentioned.

Houses that are poorly maintained, or with brittle plaster walls, can experience aesthetic damage once the PPV approaches 1.0 IPS.  Sound residential structures have a damage threshold value of 2.0 IPS, and commercial structures are at 4.0 IPS.  These values show that there is quite a big difference between the size at which the human body begins to notice a vibration and the size of a vibration that will cause damage to a building.

Most construction sites that involve the use of explosives are required to do pre-blast surveys to map the existing cracks or other defects in buildings within a certain radius from the blasting activity and to measure the vibrations produced during construction.  If the vibrations from the blasting exceed the threshold level and damage is reported by the homeowner or business owner, the contractor can determine what damage existed prior to the blast so a comparison can be made, and any damage caused by the construction can be repaired.  Cracks caused by construction vibration, whether from blasting or from large equipment, look very similar to typical settlement cracks or cracks caused by moisture and thermal changes in the structure.  Therefore, it is important to know which cracks existed prior to the construction activity.

Construction sites that do not involve blasting typically do not perform preconstruction surveys of the adjacent buildings to map wall cracks and other pre-existing conditions because the likelihood of damage is very small.  Devices to measure the vibrations produced by the construction equipment are also not typically used.  Claims against a contractor typically occur when vibrations are felt by a home or business owner and they notice cracks in the interior walls, veneer, or foundation of the structure.  Vibrations produced from typical construction machinery located approximately 15 feet from the structure are measured at the following PPVs: a small dozer – 0.008 IPS, jack hammer- 0.07 IPS, a large dozer – 0.2 IPS, and a vibratory pile driver – 1.5 IPS.  All of these activities except for the pile driver are well below the damage threshold for all structures; however, the vibrations produced by the machines will be noticed by the human body.

While the noise and the vibrations produced by nearby construction activity may be discomforting and disruptive to daily activities, rarely are the vibrations damaging to structures.  Contractors should be aware of historical buildings or dwellings that are in disrepair when performing activities in proximity to these structures.  If heavy machinery is going to be operated around these structures, consideration should be given to performing a preconstruction survey of the structures to document pre-existing conditions that later may be confused as damage caused by the construction.

Find more articles here!

We pride ourselves on not only responding  to your catastrophe needs, but also in continuing to be there to support your day-to-day needs in areas not directly affected by Mother Nature’s wrath.  At Donan, we understand the many challenges that come from handling these catastrophic situations, and we will work hard to help ensure your ability to service your customers’ needs in the timely manner they demand.

To submit your project, please visit our project submission website at http://donan.interactivemedialab.com/Login.aspx or call us toll free at 800-482-5611.

Donan already has Florida offices in St. Louis, MO and Orlando and Tampa, FL.

Kevin B. Abell, chief sales and marketing officer, said in the release, “The firm is already doing a substantial amount of work in that part of the state from our central Florida offices, and we feel that the value added for our customers will be substantial with us having a physical presence in the southern part of the state.”

He added that the company is “continuing to push the boundaries of our company footprint” so more clients can hire Donan to conduct forensic engineering investigations and fire origin and cause investigations.

Visit donan.com to sign up today!

You can also read previously distributed articles here!

Commonly asked questions about the Project reporting Tool and the sign-up process:

1. What is the Donan Engineering PRT?
The Project Reporting Tool is an online system available at www.donan.com that allows our clients to sign-up for an account.  This unique account will allow you to log-in to submit new assignments, to track the progress of your ongoing projects, to review or reference any previously assigned projects, and to receive and review your completed projects.

2.       How do I sign up for a PRT account?
To sign up for an account with the new PRT, you simply need to click on the “Project Reporting Tool” icon, which is located on the right-hand side of the of the Donan Engineering website’s homepage at www.donan.com.  Once you have clicked on the Project Reporting Tool icon, you will be redirected to the page that allows you to sign-in if you already have an account and where you can sign-up if you do not already have an account.  Simply complete the online registration form with your information and preferences and within a couple of business days you will have a verified PRT account.

3.       What if I have used the PRT in the past for retrieving reports, will I still need to sign-up for an account or will an old User ID and Password work to access the new PRT?
All users will be required to sign-up for a new PRT account.  During the initial sign-up, you will be able to create your own unique User ID and Password that will remain the same going forward and will replace the previous process of separate User IDs and Passwords being assigned by Donan Engineering for each project.

4.       I see when I click on the Project Reporting Tool icon where I can still submit a project without signing up for an account.  What are the advantages of signing up for an account since I can already submit my assignments without one?
Once you complete the account sign up process and your account is verified, you will no longer have to re-enter your contact information when you assign projects as the PRT will auto-fill those data fields with the contact information you supplied during the initial registration process.  Creating an account will also allow you to review ongoing and past projects, while simply submitting projects will not allow you access to this data.  You will also need your account to receive projects online through the PRT, so if you wish to receive your completed reports and pictures via our online system you will need an account to access this data.

5.       When I signed-up for my new Project Reporting Tool account I received a message that my account needs to be verified and that it could take up to 2 business days for this to occur.  What does this mean and is this typical?
As part of our sign-up system all accounts must go through a verification process to make sure they are properly linked to our internal database, which will allow for the proper displaying of reports and data within the PRT.  This is a one-time process and will ensure that your account is properly set-up and functioning prior to your initial log-in attempt.

6.       Once I have a verified PRT account User ID and Password, what will I be able to access now that this upgrade is complete?
When you log-in to the PRT, you will see a screen that contains all ACTIVE Projects and also any previously COMPLETED Projects.  Along with each project there will be fields that include the Donan Engineering Project Number, your internal Claim Number (if applicable), the Status of the project, the Project Managers Name, the Donan Engineering Project Name, the date the project was submitted or STARTED, the date the initial SITE VISIT occurred, the date the project went into TYPING, and date the project Report was Sent if the project has been completed.

7.       I see several different statuses listed for my active projects, but I don’t really know what those mean.  Can you define the different types?
There are four different status types that Donan Engineering uses to properly tag active projects.  Those project types include Inspection, Report, Typing, and Hold/Ongoing.

Inspection – a project that is awaiting the initial site visit or inspection to be performed

Report – a project where the initial site visit has been conducted and the project is now awaiting the completion of the written report

Typing – a project where the initial site visit and writing of the report has been completed and the project is now awaiting the completion of the peer review and final editing for grammar and punctuation.

Hold/Ongoing – a project where special circumstances have resulted in a delay in the progress of the project.  There can be a number of reasons for this status, but some of the more common ones include where we are asked to hold by our client, where a joint study must be scheduled and performed, where legal proceedings are delaying completion, etc.  For any project in this status, your project manager will actively communicate with you to ensure that everyone is on the same page regarding the progress and expectations of the investigation.

8.       Under my completed projects there are two different status types, so can you explain the difference between Completed and Closed?
The difference is very simple between Closed and Completed as a closed project is simply a job that was cancelled by the client prior to the end of the process and a completed project is one where the project manager has completed their work on a project.

9.       How will I be notified when I have a new Completed Project available through the PRT?
Once a new project is completed, you will receive an auto-email informing you that there is a new project available for your review.  The email will contain all of the pertinent information necessary for identifying the completed project including the Donan project number and your claim number (if applicable).

10.   Are there future plans for additional upgrades to the PRT system?
Yes, we are continually looking for ways to enhance the customer experience and we have plans for future improvements to our new Project Reporting Tool.  At this point, our future upgrade list includes adding supervisor access to multiple PRT accounts, adding live comments from the Project Manager so you can see exactly what is taking place during the life of a project, and adding turnaround time counters under each project to monitor the length of time a project has been open.

11.   How can I update my profile if I have changes that need to be made?
When you log-in to the Project Reporting Tool you can quickly and easily make changes to your profile by simply going under Settings and selecting Update Profile.  Once the Update Profile page loads, you will select the Edit button at the bottom which will allow you to make changes to your personal information and password for the PRT.

12.   Can I still register for a PRT account if I don’t want to give out my email address?
Yes, you can still sign up for an account, but there are some real limitations without an active email address attached to an account.  All notifications including the initial verification of your account, acknowledgement of a new project submission, and the notification of a completed report are sent via email so without an account you will not be able to receive these items.

13.   I am having technical issues and I need to speak with someone at Donan to try and remedy the issue, who should I contact for help?
You can contact Donan Engineering for help by emailing donan@donan.com or by visiting our Locations page at www.donan.com and calling any of our local offices.  Any of our administrative staff should be able to help you troubleshoot technical issues or to refer you to the right person depending on the type of issue you are experiencing.  You can also contact our main toll-free number at 800-482-5611 and ask to speak with someone regarding technical issues with the Project Reporting Tool.

Donan Engineering is proud to offer our clients a flat-fee option for residential asphalt shingle roofing investigations. We took your comments/request/demands and are giving you something to better anticipate and control your expenses when trying to determine if a residential asphalt shingle roof has sustained wind and/or hail
damage.

Here is what you are going to get:

– A “short-form” report, typically 2-3 pages on the subject loss
–An EagleView™ report when available
–Up to 12 captioned photos of the loss scene
–Inspection of any outbuildings such as storage sheds or unattached garages (no restrictions on building size)
–Limited to single-family dwellings
–Must be asphalt shingle roofing–Must be one- and /or two-story
-One hour round-trip travel from our nearest office (If for some reason we need to go over this travel time, we’ll
just invoice at our standard travel and mileage rates.  Don’t worry though, we’ll call you first!)

Of Course there are always a few restrictions, right?

– Contractors or attorney involvement may, at Donan’s discretion, result in cancellation of flat fee (If this occurs,   one of our professionals will be sure to call and confirm this with you, the adjuster, during a verbal report following the site visit and before any additional charges have occurred)
– Condominium and/or apartment buildings do not qualify for flat-fee pricing (But of course, we would be happy to discuss flat-fee arrangements on a case-by-case basis for these types of scenarios)

Now that sounds like a pretty good deal!  If that doesn’t get you, click here to learn more about the flat-fee, including a sample report, photos, and EagleView™!

Log on to www.donan.com to submit a job online, or give us a call at 800-482-5611.
Make sure you ask to be considered for the flat-fee roofing rate!

You cal also check out our website to learn more! Or post a comment or question!

Beginning on July 1^st, we will be open for business in both South Carolina and Iowa!!!
For contact information, please go to www.donan.com/locations.

Why all the changes and upgrades you ask?  Well, we are committed to being a leader in all facets of our business, so whether it’s informative content, ease of locating one of our 25 offices, the simplicity of assigning us a project or the convenience of communicating with our team that you seek, our upgraded web presence will be able to deliver.  Every change we have chosen to focus on has been done so with you, our valued customers, in mind.

Our enhanced website is chocked full of new content, improved navigation, and upgraded photos which will allow you to quickly and easily find what you seek.  We understand the frustration of visiting sites and not being able to locate what you want or need, so we have worked long and hard to make sure our site does not fall into this category.

As for the new DONANOLOGY blog, well this blog is going to be used to keep everyone up-to-date on everything “Donan.”  It will have entries discussing trends in our industry, interesting things we encounter on-site, updates on new service offerings, and so much more.

When everything is said and done, we want to be the interactive leader in the forensic world and this is the beginning of making that happen.  Now, it is up to you to tell us how we are doing in this quest…