How do you clean the air you breathe?

3 Myths Of Air Purification

 

MYTH: HEPA Filters Are Adequate Protection

Air Purifier manufacturers often make their claims for HEPA filtration out of context. They do not eliminate the majority of potentially lethal contaminants. HEPA filters remove a percentage of particulates only, in fact, it’s what the “P” in HEPA stands for! In truth however, it is other serious contaminants that cause the majority of serious respiratory problems.

In addition, many dangerous viruses are smaller than 0.1 microns, and can pass through typical HEPA filter systems. Additionally, gases are not considered “particulates” because their size is measured in angstroms (1/1000th of a micron), and most hydrocarbons are 4 to 8 angstroms in size. These are potentially lethal contaminants that a HEPA filter cannot remove.

You can easily see that the many HEPA-based air purifiers on the market are wholly inadequate to protect the human body from many dangerous and even potentially lethal contaminants. They are suitable to provide allergy relief and clean the air of some particulate, but true protection requires more.
The BioSmart® SA-700 Air purification system with its proprietary BioSmart® hydrophobic activated carbon filter and ultraviolet emitter can help protect you from all of these airborne threats.

MYTH: All Charcoal Filters Are Equal

Under perfect conditions (0% Humidity), natural carbon can absorb some types of hydrocarbons when used in air purification systems. Unfortunately, even though charcoal can absorb hydrocarbons, such as benzene found in cigarette smoke, it is more likely to absorb water from the air first!

Consider a one-pound carbon filter in an average home, subjected to the airflow rate of a typical air purifier system. Normally, in less than 72 hours, 90% of the effectiveness of the carbon filter has been nullified by the absorption of water!

An effective filter must be hydrophobic to avoid this absorption of water and the resulting loss of capacity. This requires special treatment not normally found in consumer air purification systems.

In addition, the filter must contain many more reactive ingredients than just charcoal in order to be effective in reducing levels of airborne volatile compounds.

Only the BioSmart® SA-700 air purifier has the BioSmart® Hydrophobic Activated Carbon filtration cartridge that can reliably achieve true eradication of hydrocarbons and other harmful pollutants.

MYTH: UV Light Purifies The Air

The word “purify” can be misleading, and it is often used loosely in the air purification industry. UV light kills harmful organisms, but it does not remove them from the air. Rendering potentially infectious organisms harmless is an important step in the purification process, but it is only part of a properly designed air purifier system's job.

Ultraviolet light is used extensively in hospitals in combination with other systems, such as gas filters. These systems are expensive and carefully engineered to accomplish a specific task. A typical consumer unit that claims to have ultraviolet cannot automatically be assumed to reliably or credibly match this performance level.

Not all ultraviolet is equal! The nanometre wavelength of an ultraviolet emitter can have a very wide range, and an improper frequency creates harmful ozone by disassociating electrons from oxygen molecules in the air.

Proper use of ultraviolet light in the air requires a higher frequency than the standard 186 nanometers, and the unit must retain that frequency in order to eliminate the possibility of the formation of ozone.

Additionally, the unit must expose the air to the proper ultraviolet frequency for a required minimum duration at a minimum distance from the source of the ultraviolet emission.

Unless all these factors have been addressed, such as they are in the design of the BioSmart® SA-700 Air Purifier, the ultraviolet will not effectively accomplish its objective.

Did you know that we can help you with equipment at an affordable price for you to own.  Contact us for more info.

Do you really need to put all that equipment in my house to dry it?

One of the most frequent questions asked, or thought about during water damage restoration work is; do you really need to bring all that equipment in my house?"

What is the process that goes into determining if we have adequate amount, or too much equipment.  There are formulas we follow, calculations we calculate, and measurements to measure.  You should never be given an answer along the lines of "because that is how much we have on the truck", or "because we always use this much equipment."  Be suspect if you do not see the technicians working hard to figure the actual need of equipment.  There are tools, and meters, and gauges available to professionals to determine the equipment requirements for each job.  Just as two people are not the same, each water damage we go into has its own wants and needs.

How do we do it.  How does Damage Control determine the equipment load needed to dry each job to a pre-loss condition, or back to dry like it never happened conditioned.

DEHUMIDIFIERS
One of my favorite formulas used to calculate the dehumidification requirements in a water damaged building is fun.
Step 1.  Simply figure how much air space is in the room or building and figure how much moisture can be put into that airspace.  Cubic feet is calculated Length x Width x Height.
Step 2.  Determine the class of water loss, classes1-4.  This is in reference to the type of water loss, location of water source, how much water is effecting the structure, and the type of building materials affected.
class 1.  water losses that affect only a part of the room, with a minimum amount of moisture
class 2.  water losses that affect the entire room of carpeting with water wicking up the walls to 24".
class 3.  water came from overhead.  Walls, ceilings, insulation, carpet and padding, virtually the entire area is saturated.
class 4.  These involve materials with low permeance.  Hardwoods, brick, plaster, concrete, stone, etc..
Step 3.  Determine the type of dehumidifiers being used and its capacity of water removal.  Each machine has different capacities and abilities.  We are looking at the number of pints of water removal per day here.  Once we have all the info needed we can then determine the equipment needs for dehumidification in that area.
Example: 1500 sf. class 2 water loss @ 12,000 cf. / 50 pints (dehu) = 240 pints of dehumidification needed.
As explained earlier each dehumidifier is different in it capacity to handle a job.  Most of our units process 120 - 130 pints per day.  So on this job in the example above, we would use 2 dehu's on this 1500 sf water loss.

Dehumidifiers are rated at pints per day.  We measure their ability to remove moisture from the air in grains.  To make sure the equipment is working properly, and still needed on that job site, we take readings each time we check on that job.  We keep track of atmosphere conditions and wall readings.  The atmospheric readings are called psychrometric readings.  With these readings we determine grains of moisture per pound of air.  It is this way we keep track of the specific moisture and compare that with the moisture content in the materials we are trying to dry.  Simply put, if the air is dry, the structure will be able to dry.

AIRMOVERS

How do we get that dry air to the wet surface?  Thank goodness there are not confusing scientific formulas for  this piece of equipment.  Each airmover is designed to push airflow.  I call it energy.  Each piece is designed differently, but measured in cfm (cubic feet per minute).  In general, an airmover should be placed with in 12 feet of another to maximize airflow.  If there are obstructions blocking the airflow, equipment can be placed accordingly to have adequate airflow.  If doors are in the way, we remove them.  Airmovers should be placed  at a 45 degree angle to push enough air to the hard to reach areas and increase airflow from the center of the room to allow carpet and padding to dry.
To directly answer the determining factor used in airmover placement; it depends on what is in the room we are drying.  If empty, the room can dry faster..!!

I hope this makes sense, and allows to clear some confusion as to why we do what we do.  The dehumidifiers are easy to calculate on paper.  The airmovers are essential to push dry air, energy, across the wet surfaces.  The 2 pieces of equipment work hand in hand to accomplish one common goal.  That goal is our goal:  Keep the Home Owner happy, and warm and dry.  Dry the structure as rapidly as possible and minimize the damages or need for repairs.

Thanks for taking the time to read.  We are standing by ready to serve, Call today @ 406-274-4168

Fall is on the way... Dare I say?

In the past few days we have witnessed seasonal changes in weather patterns.  Heat, cooling, sun, rain, lightning caused fires, and SNOW!  No it is not exactly the end of the world, it is just Montana.  I am reminded of the old adage, " if you don't like the weather, just wait 5 minutes and it will change."

With Labor Day upon us, that brings many things.  End of summer camping trips, school starting back up, and that brings College Football.  Football season brings excitement in the air.  It starts up in the hot weather and ends in the dead of winter.  There are many things that we need to do to properly winterize and safe guard them from damage that comes along with the sub freezing temperatures.  Here are some suggestions to follow as fall approaches:

- Keep up with leaves falling.  Don't allow them to collect in rain gutters plugging down spouts causing them not to drain properly.  This could open up a whole lot of problems for you when you allow water to collect where it does not belong collecting.  Make sure down spouts are draining 7 to 10 feet away from your foundation.
- Keep sidewalk clear of debris.  When snow and ice develop, they can hide other hazards that could lead to slip and fall injuries.
- Remove garden hosed from spigots or hose bibs.  Even frost free bibs will freeze and break if the hose is not disconnected.
- Drain any sprinkler systems installed in your yard.  A freeze break in your sprinkler line can lead to costly repairs from damage caused by unwanted water intrusion.
- Leave heat on in your building with the cupboards open to allow heat in there if you are planning to travel and be away during the colder weather.

These are just a few suggestions aimed at preparing you for the end of summer weather.  Winter will be here before you know it.  Yes, it was a beautiful summer, and No, I am not trying to rush it out the door.

If you are out at a local High School Football game, maybe I will see you while I am on the sidelines, at a stadium near you.  Enjoy what is left of the good weather.

Never forget that we are standing by to serve in a time of need.
Call immediately with a water concern.
406-274-4168

Decontamination / Mold remediation.... Our process spelled out..!!

It seems to be a mystery among remediators of contamination and mold as to which method or product they use.  The varying methods and fungicides and biocides differ greatly in this industry.  This is the reason there so many options for which company you choose to hire to perform these services in your home or business.  I would like to shed some light on what sets  Damage Control LLC apart from other companies in our market area.  Or as I think of it,  the reason you should hire us.

It is imperative that the steps to a safe remediation be followed.
1.  Find source of water - water is necessary for mold to grow
2.  Correct or Repair the source of water -  fix the pipe, or wait for the water table to go down
3.  Conduct a preliminary assessment -  what is contaminated, and how far is it spread
4.  Identify the type of contamination -  is it catagory 1, 2, or 3
5.  Design the remediation strategy - what do I need to use to kill/stop contamination
6.  Set up containment area -  contain the area that is affected
7.  Suit up and enter containment area - use personal protective equipment
8.  Perform the remediation - hepa vacuum and remove the contaminants and use the proper chemical for the contamination and hepa vacuum again
9.  Dispose of contaminated debris - contain the contamination in sealed bags
10.  Clean up - make sure debris is bagged, and properly cleaned
11.  Containment exit protocol -  hepa vacuum and wipe all equipment and tools used in remediation, and hepa vac and wipe all things that will exit the contained area
12.  Post remediation evaluation - visually inspect and smell for any mold odors prior to conducting clearance testing by a Certified Industrial Hygenist
13.  Break down of containment -  clean up and return house hold items
14.  Document the entire process - report of procedures

Through out this process, it is crucial to communicate with all involved parties.  This includes the homeowner, and technicians performing the remediation, as well as the hygenist performing the clearance testing.

The above listed 14 steps are industry standard for proper mold remediations.

Question:  Where does the varying types of remediation occur, and what is the difference in techniques?
Answer:  Step 8

I have recently heard many varying types of remediation techniques.  From high pressure washing with water and chemicals, to sanding and air pressure washing following sanding with out chemicals.  This is a wide spectrum of options with varying hourly rates that will be tabulated in a bill format.

Our process involves Chlorine Dioxide.  What is this?  Where does it come from?  Is it safe?
There was an article that I read in the paper recently where some who lack proper education have called it bleach and reffered to it as a scam. 

Please follow the link to learn what the epa study has shown :  http://www.epa.gov/ogwdw/mdbp/pdf/alter/chapt_4.pdf

The metabolism of microorganisms and consequently their ability to survive and propagate are
influenced by the oxidation reduction potential (ORP) of the medium in which it lives (USEPA,
1996).
Chlorine dioxide (ClO2) is a neutral compound of chlorine in the +IV oxidation state.  It disinfects by
oxidation; however, it does not chlorinate.  It is a relatively small, volatile, and highly energetic
molecule, and a free radical even while in dilute aqueous solutions. At high concentrations, it reacts
violently with reducing agents. However, it is stable in dilute solution in a closed container in the
absence of light (AWWA, 1990).  Chlorine dioxide functions as a highly selective oxidant due to its
unique, one-electron transfer mechanism where it is reduced to chlorite (ClO2) (Hoehn et al., 1996)

Our chlorine dioxide generator can be used in the following applications:

• Municipal treatment plants
• Wastewater disinfection
• Water reuse and recycling
• Horticultural irrigation
• Corrugators and paper manufacturers
• Food processing plant sanitation
• Cooling towers
• Bathroom sanitation and odor control
• Septic tank odor control
• Drinking water disinfection
• Agriculture
• Fruits & vegetable sanitation
• Oxidizing agent

Typical Properties Include:

• Biocide
• Viricide
• Fungicide
• Sporicide
• Water Disinfection
• Sterilizer
• Odor neutralizer
• Taste removal
• pH and viscosity stabilization
• BOD and COD reduction

Common Microorganisms Eliminated:

• E. Coli
• Legionella
• Pneumophilia
• Streptococcus Facalis Bacillus
• Clostridium
• Amoebae
• Giardia
• Cryptosporidium
• Pseudomonas

Damage Control has put a lot of effort into finding a solution that is safe, and effective for use in your home following a flooding catastrophe such as we are experiencing currently.  We do use other types of chemicals to kill these types of spores and bacteria, but Chlorine Dioxide has proven to be effective and safe with out leaving a dangerous residue.  

Following the chlorine dioxide treatment, we apply a protective coating that has an additional anti microbial agent in it.  This product gives a 5 year warranty against re-growth of molds from this flooding in the treated area.  This gives peace of mind, and comfort to a job well done.  Also aids in resale if your real estate is subject to that.

In mold remediation and decontamination, it is important to use a product that will eliminate the very microorganisms that threaten health and happiness.  Be comfortable with the choice you make in hiring someone to clean up after flooding.  Make sure they are insured, and certified.  Make sure they are experienced and can provide references.

Most importantly, make sure that what they are telling you makes sense...!

For a  FREE no obligation consultation, and a quote, call today..!!

Damage Control LLC

(406)274-4168

What Do I Do While I Wait???

The crawlspace or basement is full of water.  The flow of the river brought the current into my basement and now I am stuck with it.  As a result of the flooding river, the water table is elevated and nothing will dry.  What do I do?  What is this going to cost me?  Should I pump it out, only to find the water level in my home the same? Should I put a fan blowing air into my crawl space?  Am I going to have mold growing in my house?

These questions are asked daily, over and over again.  One neighbor is pumping water out of his crawlspace and the guy next door is finding water increasingly coming into his home.  WE ARE ALL IN THIS TOGETHER..!  Wet is wet.  Our community is wet.  It will not go away all at once, and we share the same elevated water table.
I have checked from Darby to Thompson Falls, and Drummond to Whitefish, and found the same situation;  water in crawlspaces and basements...!

So what is the answer?  What should we do?

Just as a chef in a kitchen has to use ingredients to make a meal fit for a king, the drying process has ingredients that will create evaporation and remove water from its unintended hiding spots.  Airflow, Humidity, and Temperature are the essential ingredients necessary in order to make wet things become dry.  An example of this is your laundry.  You wash your cloths in the washing machine, then you transfer the wet clothing into the dryer or put them on a cloths line in the yard.  Lets look at how the dryer works.  There is heat from the heating elements.  There is airflow which also controls the humidity removing that moisture through the air and depositing it outside.  Think of it as a drying vacuum which sucks the wet air out side and maintains an airflow blowing outside into a separate air system.  We need to set your home up like a cloths dryer.  We need to be able to control the temperature, humidity, and airflow to return your home to the dry condition it once had.

Picture with me a crawlspace full of water.  Imagine the entrance is in a bedroom or hallway closet and there are no vents outside.  Now lets envision a panic stricken  homeowner that is desperately trying to save his/her home.  What should he do?  Sadly enough, this is all to real, it is not much of a stretch of the imagination to envision this taking place.

Our problem is difficult to deal with.  We are experiencing high water table, ground water, and high flowing rivers that are above flood stage.  In order to get this dry, we need the water to go away, we need the water to recede and the rivers to return to the boundaries of their banks.  Any attempt to dry or pump water out with high water levels like this would be just like putting your laundry outside to dry on the cloths line during a rain storm.

What we need to know, and what we need to do until the water levels go back to normal can be complicated.  Patience will be key.  The ingredients to drying are going to be important as we wait, we do need to keep moisture from migrating into more areas that it does not belong.  Remember that water will evaporate as we go through the process of waiting on the rivers levels to recede.  As the evaporation process occurs, the moisture becomes airborne.  This wet air has to travel somewhere.  As the day time temperatures rise outside, the humidity drops.  As the outside air temps drop, the humidity will rise.  What happens when to that moist air from our crawlspace when the outside air temperature drops below that air temperature inside our crawlspace.  The dew point temp will create vapor pressure that will try to balance, or reach a equilibrium.  Through this process, we can have and will see condensation.  The trick to staying out of water trouble, mold problems, etc. is how do we balance the air pressure to make sure moisture is not migrating to unseen areas and will later develop into a mold problem.  Water damage restoration companies like ourselves are highly skilled, and we use high tech equipment to monitor and diagnose moisture levels in your walls, floors, ceilings, and air spaces inside and outside your home.  We use tools to measure air speed on negative air systems to ensure that it is what we designed it to be.

When using airflow, the general rule of thumb is "negative air always."  Negative air pressure is defined as;  a condition which exists in a building when less air is supplied to a space then is exhausted out from that space.  With the given situation at the current moment, we need to apply this in our homes.  The best way to safeguard against unseen moisture migration, and potential mold problems is to create a negative air pressure system in your home.  This will keep any airborne moisture moving outside and keep it from being absorbed into building materials.

One caution I would issue with adding airflow into your drying system is the potential for airborne contaminants to become present.  Also there is a risk of bringing high levels of moisture into the airspace as it travels via make up air.  Make up air is defined as; air that is brought into a building from outdoors through ventilation or air gaps in building construction.  Regarding airborne contaminants,  it is essential that your property goes through a decontamination process.  This process can be a threat to you while it is being applied.  Bleach water may not be the best option.  This needs to be done by trained professionals, who are licenced and insured to perform these types of practices.

The above listed principles need to be considered before you start pumping any water out of your home.  Pumping the water out will rapidly increase evaporation, and facilitate moisture migration into unwanted areas thus causing mold problems.  You also need to be mindful of your neighbors foundations, and wall systems as you pump.  Hydrostatic pressure can be very destructive if not respected properly.  If there are 5 houses in a row with wet crawl spaces, and the middle one starts aggressively pumping water out while the others are not, he will put his home, and his neighbors at risk of slab and foundation issues.  You can create a land slide under water, and under the foundations that will cause the ground to settle differently and adversely affect the neighborhood.  You need to respect the force water can have if not applied properly.  Those 5 homes need to be pumping in harmony, and at as close to the same rate as possible in order to protect the neighborhood.  How do you think the grand canyon was carved?  Remember water is powerful.

Remember that the water levels need to go down, the river needs to return to the boundaries of its banks, and the water table needs to stabilize before we can see the light at the end of the tunnel.  Let us guide you through the darkness of the waiting process.  We are here to help, and will be available with the equipment, and know how to get to that bright day in the future.  Fear not my friends, we will win!  We will overcome this adversity in our lives, water and mold will not stop us.

If money and financial concerns are stopping you from calling in the professionals to help with you, we have sympathy and can work out what ever you need to in order to protect your home.  We are standing by ready to serve.

Call today:
Damage Control LLC
406-274-4168

High Waters, Rivers Flooding..

As the National Weather Service calls it "a sensational runoff" this spring, our rivers and streams are on the rise.  This whole state of Montana is affected by high waters.  The eastern part is under water, the western part is headed that way.  Schools have been land locked with students trapped inside by flood waters.  AND ITS ONLY JUST BEGUN..

Some homes in our area are already flooded from the Clark Fork River, these houses can use the title of the film  by Robert Redford "a River runs through it".  Others are sandbagging their properties in hopes to ward off the would be intruder.  What shall we do, what if the river rises and comes into our homes like an unwelcome guest?

Recent News headlines give plenty of warnings ; "Governor declares state of Emergency", "Flood waters taking over Missoula neighborhood". We could list many more headlines than this.

What are the concerns, and how can my house be safe again, live able again?  First off, we better listen to the health and wellness experts.  In a recent news article the County Health Dept. warned of contamination.  In their own words, they explained the following; "Flood waters can contaminate water systems like wells. Officials say you should use bottled water until your system is inspected and cleaned. For now this is only a warning for people however, several precautions should be taken if the water keeps rising."

It is necessary to think that the flood water is unsafe, and contaminated.  It is flowing over areas, that usually do not get water and picking up bacteria along the way.  As it affects our homes, and brings unwanted invaders, we need to be cautious and take necessary steps to clean up.  There are several things that need to be done once the flood water recedes. 
First call Damage Control LLC at (406)274-4168.  These are the steps our team will follow to restore your property:
     1. Remove as much water as possible.
     2. Remove any porous material that the water affected, ie. carpet & padding, furniture, etc.
     3. Remove building materials affected, ie. drywall, insulation, etc.
     4. Begin structural drying with the the aid of mechanical procedures, professional equipment.
     5. Deodorize and decontaminate, sanitation of the structure.
     6. Clearance test for microbiological contaminants, get a clean result
     7. Begin reconstruction phase.

These steps are what professional decontamination contractors and restorationists like ourselves use during large scale flooding all over the country.  This scale of flooding will not, WILL NOT, dry itself out.  You simply can not "leave the windows open" and let the building "air out" in this situation.

Our response team will be ready, the minute the river level stabilizes.  Damage Control's disaster response crews are ready, willing and able to save your property and return it to its comfortable condition.  After all, your home is your castle, and we will return it to that condition as you expect.

Remember, we provide a no obligation evaluation free of charge.

Call today with any questions,
Damage Control LLC 
(406)274-4168.

Water around my foundation, or in my crawlspace..!! What do I do..?

French drains are often installed around a home foundation in two different ways:

• Buried around the foundation wall on the external side of the foundation
• Installed underneath the basement floor on the inside perimeter of the basement

In most homes, an external French drain or drain tile is installed around the foundation walls before the foundation soil is backfilled. It's laid on the bottom of the excavated area, and a layer of stone is laid on top. In many cases, a filter fabric is then laid on top of the stone to keep fine sediments and particles from entering. Once the drain is installed, the area is backfilled and the system is left alone unless it clogs.
While an external French drain can operate for ten years or more without the need for maintenance, it's prone to clogging without any warning and can eventually lead to a flooded basement. When there is no filter fiber, sediments can make their way through the stone as years pass and clog the drain, and when the filter fabric is present, that can instead clog with sediments. It may be wise to provide cleanouts, much as is done with sanitary sewers, to provide access for inspection with a camera snake. Also, a French drain that is not installed with a sump pump counts on gravity alone to drain foundation water, and if the house is not located on a hill or near a steep incline, finding this slope can be problematic. Additionally, maintenance on an external French drain involves expensive exterior excavation, which includes removal of walkways, shrubberies, porches, gardens, and anything else along the perimeter.
Installing a French drain around the inside perimeter is most commonly done after the house has been built. Most commonly, this is done in response to a wet basement or right before performing a basement finishing. To install this kind of drain, the perimeter of the basement floor is jackhammered down to the footing and the cement is removed. A layer of stone is laid down, and the drain is laid on top of it. Water is collected from the basement wall floor joint as it enters, and a sump pump is installed to pump the water out of the house and away from the foundation.
Once completed, the area, save for a 2 in (5.1 cm) gap around the edge, is cemented over. This gap exists in order to allow water in from the basement walls. This can be installed very quickly- 1-2 days by an experienced crew. The system is easy to maintain once installed, and the sump pump will need annual maintenance to perform properly. An interior French drain is much less likely to clog than an exterior, partially due to the fact that it is not sitting underneath several feet of soil.
Interior French drain installation is an effective way to waterproof a basement but requires the use of a sump pump. Many contractors will install plastic sump pumps that can quickly break down or neglect to install a battery backup sump pump, making the basement vulnerable to flooding during power outages. Sump pumps should be installed with a battery backup system in a proper sump liner of 20 US gal (76 L) size or larger to prevent the sump from having too little water and turning on and off continuously.

Moisture Mangaement from outside

Do you ever get moisture around your windows?  Does it ice up when it is cold outside?  How old are your windows, What quality are they?  WERE THEY INSTALLED PROPERLY?

One of the biggest unseen problems in keeping your home warm and dry is the building envelope.  The relationship your home has with outside.  This is the battle of keeping outside, outside.  There are tremendous efforts to keep builders educated as to the latest and greatest techniques to ensure proper water management details in construction.  At times there are let downs in this science, and we who live in these homes deal with the negative effects from this.  One of the most common errors in sequencing of construction occurs at the window.  The window is a very important aspect of the walls construction, and an integral part of the building envelope.

Often, due to the different trades on the site, or the sequencing of materials being delivered to

the site, the windows may be installed before or after the installation of the drainage plane

material. In either case, provisions must be made to allow the window to be integrated into the

drainage plane of the assembly. It is important to ensure that the building paper or housewrap

laps over the flange and self adhered membrane at the head of the window. If the building

paper/housewrap is installed prior to the window, then a flap of paper at the head should be

turned up during the installation of the window, then the flap can be dropped back down over the

top of the flange. Using self adhered membrane flashings and other tapes to seal the nailing

flange at the head of the window, while reducing the risk of water intrusion, still create a reverse

lap and must remain completely sealed for the service life of the installation in order to be

effective.

Other issues dealing with problems at the window can be related to damages, bends, or cracks in the flange.  The house wrap will not seal properly and have a adverse effect. 

All in all, in our efforts to keep you warm and dry and mold free, we try to give you some things to think about. 

As always, we stand by to give you the aide you need.  24/7 we respond to your need.  Call today.  (406) 274-4168

Drying Methods Explored

Drying Methods Explored

(Positive-Negative-Passive)

by Ernie Storrer

President--Injectidry Systems, Inc.

Positive, negative and passive

It is now universally accepted among knowledgeable restorers that wet building material should be dried and returned to equilibrium as soon as possible after a water damage. When the unexpected water intrusion occurs, there is often confusion as to what materials are wet, how wet they are, and what if anything should be done to effect drying. For the purposes of this article, it is assumed that structural moisture content readings have been taken after a water loss and actions should be taken. Moisture has been found in locations and quantities that are not normal for this specific building.  The article further, will deal with specific drying methodologies that we will call: negative, positive and passive.

First, several concepts about air and moisture as pointed out by Joe Lstiburek of Building Science Corporation: *

·        Air flows from high pressure to lower. Air molecules will move to a less crowded space if you will. In the atmosphere, weather systems exhibit this tendency when air (wind) moves from zones of “high pressure” to zones of low atmospheric (barometric) pressure. In a building, the same phenomenon occurs only on a much smaller scales. A visible evidence of this air movement is the “soil filtration” lines in buildings. Contaminated air moves across the face fiber of carpeting and deposits its load.

·        CFM in = CFM out. If air is moved into a space, an equal quantity has to come out in order to equalize pressure.

·        The action happens at the surface. Assuming the surface material is wet, the movement of dry air over and by it, will cause the material’s moisture to transfer to the air. This air activity will act to retard mold growth. (If the structure is not dried, the relative humidity will be elevated and mold will result, just about guaranteed).

The understanding of these concepts will enable the restoration contractor to better visualize what needs to happen and how structural drying can be accomplished. Moisture is present and must be removed from affected materials that surround interstitial spaces. A vehicle, air that is dry, is used to convey the moisture from the wet surface material to the exterior of the trapped area. Air forced into or through the area of entrapment must come out with its load of moisture, resulting in drier structure.

Passive drying

Let’s deal with “passive” drying first. A passive attempt describes measures that do not directly affect wet areas with moving dry air. Passive attempts are essentially inactivity without the use of mechanical devices. Instead of actively opening up wet interstitial spaces and moving air through them, methods are used to let things happen more slowly, perhaps by simply allowing the wet structure to equalize on its own. An example of when this might be done would be when a wall is encountered that has no paint and is only wet up several inches from the floor. There would often be no effort that would be worth taking, as the wet material will often rapidly dry without intervention. Even if dehumidification were undertaken, “passive” would still be the definition unless the dehumidified air was concentrated and blown on the wet area.

Water vapor pressure

A more aggressive step than simply letting the structure acclimate and equalize on its own, would be to change the vapor pressure present in the structure. In almost all cases where excess water has intruded into the built environment, there is a change of and an increase in water vapor pressure. Water vapor pressure can be defined as “the exertion of force by water upon a surface.” This pressure will change if either temperature or the specific amount of moisture in the air changes. In our hypothetical water damage situation, the specific water vapor pressure will increase as the air becomes more saturated with moisture. As air moves by the wet flooring, walls or ceilings, the moisture attaches to the air molecules. This extra moisture migrates to the air if the air has the specific ability to hold more grains of moisture. Any relative humidity reading of less than 100% will mean the air is not saturated and can hold more moisture at that specific temperature. Whether or not the moisture will go to the air will depend on factors such as air movement, temperature of the air and temperature of the surface material.

Dehumidification to reduce water vapor pressure

In most cases, it is relatively easy to change the water vapor pressure by adding dehumidification to the environment. Dehumidification will remove moisture from the air, and other conditions such as temperature remaining constant, will produce reduced water vapor pressure. If the air outside the structure contains less specific grains of moisture than the inside air, the wetter inside air can be exchanged with the outside by ventilating. This is almost never practical for an extended period of time, as both the inside and the outside conditions will be changing. Within a matter of hours, relative humidity outside can change from 60 to 100%. It is practically impossible to properly monitor jobs closely for any length of time. If climatic changes are not reacted to quickly, moisture can even be added to the structure.

The reduced water vapor pressure in the air will move moisture from the wet structural material to the air. Moisture continuously seeks stability, and when there is a pressure differential, the moisture will move toward lower pressure, both vapor and barometric. 

Positive Drying

Some of the structural drying that contractors do, involves the use of moving air directly into interstitial spaces from sources such as airmovers blowing air directly into wall cavities. Usually large holes are drilled into the wall and air is blown directly at the wall. Sometimes, TurboventsÒ or Mini-Turbovents are used to better concentrate air at the surface. Simply blowing air alongside a wall that has holes drilled into it, is not positive drying. In fact, there is a negative pressure created as a result of the air velocity along the surface. (This is what keeps an airplane in the air)! Air is moved out of the holes drilled into the surface due to the lowered pressure at the surface. Another system used to deliver air to the wet areas is the Injectidry System. This system delivers air to the area of entrapment behind the surface instead of at the surface. The air is not released from the injector nozzles until it is in the area of wetness behind the surface.

Positive drying has several advantages including the delivery of air of known temperature and moisture content. The act of pressurizing a space means we capture air from a known area such as the output face of a dehumidifier where we know the humidity is controlled. This air is lower in moisture content than the air in the surrounding area. Positive drying is almost always the fastest and most efficient use of energy due to the direct concentration of processed, drier air.

The biggest problem is that air blown into the space must come out (cfm in = cfm out). The act of moving air into the cavity will cause the dispersal of dust and debris from the space. In most cases this will not be a large problem, but where there are concerns about the health of the building occupants, this drying technique can cause the spread of mold and dust. In fact, all buildings contain contamination to some degree within walls and ceilings. If those who occupy the building wish to minimize the impact of the drying process on the structure and occupants, blowing air into the walls could be unacceptable. Examples of such situations could include:

·        hospitals and nursing homes

·        homes with elderly people or young children

·        homes with asthmatic or allergic occupants

·        homes with occupants of compromised health

·        food establishments

·        production facilities where “clean” is the only option.

Negative drying

The answer to most of the above mentioned concerns is the concept of negative drying. If moving the possible contamination outside the wall into the built environment is a problem, standard positive air movement is not the answer. The effort should be to move the moisture and contamination to a known location where no damage can happen. This can be accomplished by the negative pressurization of the interstitial space by removing air from the area. The air can then be processed either through a HEPA filter system, or moved to the exterior of the built environment. This transport can be achieved by attaching a hose to the Injectidry System or other air delivery apparatus to convey the moisture laden, contaminated air to another location. This approach is the preferred one by most Industrial Hygienists, architects and building engineers. The goals of structural drying should include the goal of not spreading contamination or making the damage situation worse. The situation that exists when we arrive at the job should not degrade as a result of our actions or inactivity.

Positive and negative drying combined

In some cases, it is both practical and desired to combine the insertion of dry air into the wet spaces while simultaneously extracting air from the area. When a structure is comprised of fairly wet floor to ceiling lath and plaster, extra insertion and extraction points will facilitate drying. Additionally, the circulation of air from top to bottom and from bottom to top will accomplish drying without the problem of dust being forced from the wall from simple positive drying. This combination was recently used on a Karate studio wall which had three layers of ½” drywall and one layer of plywood (there were four 7’X10’ mirrors attached to the wall). The wall was saturated up several feet and was dried out in 8-10 days using a combination of positive and negative pressurization. This method obviously takes multiple systems.

Where does the air go?

Each stud cavity has approximately 35 linear feet of stud and drywall contact area (both sides of stud cavity). With an average of 1/100^th of an inch of clearance between stud and wallboard, there is ½ sq. inch of open area per stud cavity. This is a more than adequate amount of area for the air to escape from the wet space, although there is a back-pressure exerted in the form of resistance. This resistance is due to the amount of structural material the air has to pass by before finding an exit (or entrance) point.

Under the terms and conditions of standard insurance policies, the insured is to “take such steps as are necessary to preserve and protect from further loss and damage.” This is an obligation we are fond of quoting to those who call in with damage. In the same manner, we as professionals are responsible for availing ourselves of knowledge, techniques and equipment in order to accomplish results that are readily available to the industry. The body of knowledge available to all professionals, is a measure of our responsibility and liability. What should you have known and when should you have known?

*WLI Water Loss Mitigation Specialist Workshop, October, 1996, Chicago.