Attic Ventilation

Few things are more misunderstood about the home than attic ventilation. In essence, all ventilation is about circulating air to keep it fresh and to reduce moisture levels. The American Institute of Architects estimates that 90 percent of homes in the U.S. have unacceptably high levels of moisture. Understanding whether your home could benefit from some form of attic ventilation might just be, if not a life-saver, a roof-saver. Here are some of the myths and the facts you need to know about attic ventilation.

1. More Attic Ventilation is Good: Just like properly sizing your furnace and air conditioning unit, you want precisely the right amount of attic ventilation for your home. Insufficient ventilation can lead to moisture problems during the winter and decreased energy efficiency during the summer, but too much ventilation can be just as bad, if not worse. Roof vents create an additional roof penetration—essentially another place of vulnerability where leaks can occur. Some vents are necessary, but you don’t want to needlessly increase the number of roof penetrations. More than leaks, these seams can cause blowouts during a hurricane or allow sparks from a wildfire to enter your home and set it ablaze.

2. Roof Vents are for Warmer Climates: Too many people believe the importance of roof ventilation is to increase energy efficiency during the summer. Good roof ventilation can do this, but shingling color, sun exposure, and insulation are exponentially more important to overall energy efficiency than ventilation. Sure, installing roof vents for older homes can reduce your cooling load during the summer, but there are probably more low-risk, cost-effective ways to increase your home’s energy efficiency.

Meanwhile, preventing moisture damage is a much greater benefit and applies to colder climates more than warmer ones. In fact, the colder the climate, the more likely it is that your home will benefit from attic ventilation. In order to install an unvented roofing system in colder climates, you’ll need highly rated, rigid insulation to prevent condensation on your roof sheathing. In warmer climates, you don’t need to worry about condensation—think about how often dew forms on your grass. In these climates, hot attic spaces are eliminated by installing a thermal barrier along the roof line, instead of the attic floor.

3. Roof Vents Remove Warm Air during the Winter: Too many people believe that because heat rises, ventilating an attic space during the winter means you’re releasing warm air and creating a drag on your heating efficiency. If this is true, you’ve got bigger problems to worry about than letting warm air escape from your home. Poor insulation is usually the culprit, although if you enter the attic on sunny, winter day, your attic space can be warmed by the sun more than your furnace.

Unless your roofing system has insulation on the roofing deck and is designed without ventilation, your furnace should not be heating your attic. Worse yet, inadequate insulation is almost surely allowing moisture-laden air into your attic. When this warm, moist air hits your roof, it’s likely to form condensation that will lead to further deterioration of your insulation and/or wood rot. If you think this might be a concern, wait till the sun goes down and measure the temperature in your attic. It should be pretty close to the outdoor temperature.

The ideal roof / attic ventilation would consists of combination of vents located in upper section of the attic (ridge vents, turbine, box shaped or dome static vents, electric motor powered vents), vents installed along the bottom parts of the roof overhang, called intake, or soffit vents, hip vents, and / or gable vents.  Roofs with no, or very small overhang might be able to utilize “vented drip edge” .

Do not combine attic gable vents with roof soffit and ridge / upper roof vent systems – it will disturb attic ventilation process.

Industry standard for proper attic ventilation recommends (for no vapor retarder type of attic insulation – no paper, plastic or aluminum layer between the attic floor and insulation layer) 1 sq. foot of ventilation for every 150 sq. feet of attic space divided 50 / 50 between the inlets and outlets.

For vapor retarder equipped attic insulation (for example fiberglass blankets/bats with paper facing),  you should have 1 sq. foot for every 300 sq. feet of attic space – assuming that everything else is perfect…

CAUTION: There are some that think the absolutely opposite, and seal all of the attic ventilation ports, sometimes insulate roof decking, assuming that such action will lower the utility bill.  They call this a “hot” roof.  Unfortunately, by doing that, they are creating the ideal mold growing environment (moist and warmer than exterior).  I have personally seen attics with spray foam on the roof sheathing, no venting and water dripping from the spray foam insulation and mold growing on all exposed lumber.

You can partially determine how good is your attic ventilation by examining roof surface during the winter (from the ground of course!).  After some snow accumulates on pitched roof surface, monitor it over the next few days, and if roof remains snow covered, there’s a good chance, that your attic ventilation and attic floor insulation is adequate, and whatever heat is being transferred through the attic floor (house ceiling), and all other penetrations between the house and attic area has enough escape routes.

Heat Loss in your Home

Do you have ice growing from your roof?  This is the best time here in Maine to evaluate your heat loss.  Go outside and look at your roof.  Are there icicles?

Owen Kiley Bar Harbor (13)    20150211_164459      20150211_084447

This build up is called ice damming.  An ice dam is a ridge of ice that forms along the lower edge of a roof and blocks melting water (snow) from running off the roof. Over time, the dam of ice builds up as more and more water freezes and the runoff water pools behind the dam–eventually working its way under the shingles right into the roof structure–and even down into the house. Ice dams are caused by heat loss from the house.  Ice dams remain a constant problem and cause millions of dollars worth of damage in northern climates. Here’s how you can prevent an ice dam on your roof.

ice damn

Understand that ice dams are caused by heat loss from inside your house. Heat rises into the attic, warms the attic and the underside of the roof and helps melt snow when the warm sun is shining. To prevent ice dam formation in homes, you need to prevent this heat loss

Ensure your attic insulation is up to modern standards. Modern building codes require attic insulation to be at least R 38 or even higher. This is approximately 12 inches of fiberglass bat insulation.

Allow cold outside air to flow through your attic. A properly ventilated attic has open soffits (under the eaves) where outside air can come in and upper vents (either individual roof vents or a ridge vent) that allow the cold air to move up underneath the roofline and out the top. This air movement keeps the roof cold and prevents an ice dam from forming.

Install baffles between the roof joists to stop any insulation from migrating over the top of the soffits, blocking the air and preventing proper air movement

However there is a more likely culprit of heat loss in your home……Attic Bypasses

These attic bypass leaks can reduce the effectiveness of your attic insulation by 30 to 40 percent.

Insulate and seal all openings (called attic bypasses) from the house into the attic. This includes chimney chases, plumbing stacks, heating ducts, attic access hatches, pot lights and ceiling fixtures. Any and all of these openings into the attic will allow warm air into the attic raising the temperature to help melt snow on the roof.

Prevent a large buildup of snow on your roof. A roof rake will allow you to pull any snow buildup off of your roof while you stand safely on the ground.

It is extremely important to get your attic bypasses sealed it you want your insulation to really work well, and to protect your home from moisture damage.  The bypasses presented in this blog are just some of the common ones.  There are many more individualized situations.

Home Inspections in Maine

Home-Inspection Whether your a seller or buyer of a home an inspection can help you ensure there are no deal breakers and no costly issues to be remedied.  Finding the right inspector is the next step.  Home inspectors in Maine do not need to be licensed.  There are many organizations that offer certification in Home Inspections these are mostly membership certifications that only require you to pay a monthly dues.  If your home inspector is taking a sample for radon air or water they must be certified by the State of Maine or it is illegal to take the sample.

Check to see if your radon professional is certified:

TP Environmental Consulting offers sellers and buyers tailored inspections to meet their individual needs.  We offer Full Residential and Commercial Inspections.  We are very competitive and our inspections are done by engineers. All our inspectors are also Certified by the State of Maine in Building, Ventilation and Energy Code.  We include a full electrical inspection by a Master Electrician and Radon Air and Water Testing by a State of Maine Certified Measurement Specialist.  Our roof to road inspections evaluate structural and environmental issues. We include pest, mold, lead and asbestos.

Environmental Evaluation  $295.00 Includes Radon air and water testing, a visual inspection of the attic and basement for water damage, mold, lead, asbestos and pest

FULL Electrical Inspection $200.00 by a master electrician

Standard Inspection  $450.00 Includes Structural, Plumbing, Basic Electrical, Heating Systems, Environmental (pest, mold, lead, asbestos), Radon air and water testing.

Here are some of the issues and cost associated with them:

Radon Air reduction systems run $1100 – $2500 depending on the house

Radon Water reduction systems run $4000 – $6000 depending on the level of radon in the water

Electrical can be as simple as proper installation of GFI’s and Smoke/Carbon Monoxide alarms or as costly as a system upgrade

Wet Basements are not unusually in Maine understanding how to maintain and improve the health of your basement is the key

Attic venting and improper attic entries are the two major sources of mold I see in attic areas.  Opening up a attic entry and seeing black staining is never a good thing for a seller to find during a buyer’s inspection.

Call TP Environmental today to help you make the right decision with the home you are buying or selling!


Is there Soot in your Home?

Soot on your walls indicates a problem somewhere in your house, and you often don’t notice soot until it’s become a huge problem. Most often, you move a picture on the wall and notice the telltale signs of soot. Upon closer inspection, you’ll probably find stains on carpets, drapes and other home furnishings as well. Ductwork can pickup soot particles and quickly spread soot throughout your home, evidenced by soot stains around registers and embedded into your air intake or filter. Before addressing cleanup, let’s address the cause.


First, if you notice soot stains around your fireplace or hearth stove, you may have found clues to the culprit. However, a byproduct of burning any fuel is carbon. If your fireplace or stove is a vented model, the problem is the venting system, not the appliance; the venting components, connector pipe, chimney liner or the chimney design itself are to blame. Either look for excessively dirty venting, a blockage such as a bird’s nest, or improper maintenance of the appliance. A fireplace or stove that has not been properly maintained may produce more smoke, fumes and particulates than the venting system was designed to withstand. Have the appliance cleaned and serviced, have the chimney cleaned and inspected.


Again, gas and oil furnaces are designed to vent fumes and soot out of the house. A properly installed and maintained furnace that’s connected to a well designed chimney and venting system should show no signs of soot. If you see soot near your furnace, have the appliance cleaned and tuned for optimum performance, then have the chimney and venting system inspected. If the venting system is oversized, undersized, contains offsets or has been blocked by leaves or birds nests, make corrections immediately. If you upgraded the furnace but attention was not given to the venting system then your furnace may not be able to perform at its optimum, and may actually be dangerous. Additionally, consider the needs of a water heater, especially if the water heater shares a flue with your furnace. The water heater may perform well in the winter when rising flue gases from the furnace assist draft, but not these fumes may linger during warm months when the chimney lacks sufficient draft to evacuate fumes. Be aware that soot caused by burning fuels (oil, gas, wood, coal) indicates another great potential health and safety risk of exposure to carbon monoxide. Soot is carbon, and where there are carbon stains then carbon monoxide has also been present. Carbon monoxide exposure can cause flu-like symptoms. Exposure to abrupt high concentrations, or long term low concentrations, can lead to permanent health damage and even result in death. If dirty walls are not enough motivation for you to immediately address your soot problem then the health and safety concerns of carbon monoxide should spur you into prompt action. Every home should have carbon monoxide detectors and smoke detectors installed relatively close to each fuel burning appliance, and on every floor of the home. TP Environmental can also point out design flaws in the venting system – such as a flue that’s too small, too short or with improper offsets – that may prevent adequate venting. If the appliance is in good repair, the chimney is clean, unblocked and designed properly then the chimney should perform its job of carrying away fumes and smoke. If not, your house design may be at fault, not allowing sufficient combustion air to enter the house. Research negative draft issues and how house designs may encourage other appliances to pull combustion air INTO your chimney.


Yes, candles can cause thousands of dollars in damage to your home before you even realize this is where your soot stains originated. The worst culprits are imported candles using petroleum byproducts and/or lead wicks. Combine these ingredients with the chemicals added to manufacture scented candles and you may have a real soot maker on your hands! Most candle manufacturers recommend keeping wicks trimmed to 1/4″ as this promotes a more even burning that results in less soot. Also keep candles away from drafts that visibly affect the flame. Never blow out a candle as this produces smoke and soot; extinguish the flame with a candle snuffer or by suffocating the fire by putting the top on a jar candle. Soy and beeswax candles are generally preferred to parafin wax (a petroleum based byproduct). Soy and beeswax are renewable resources that burn cleaner and with less chemical additives. While they generally are more expensive to purchase, they burn longer and more cleanly than paraffin wax. Non-cored wicks made of natural plant fibers are also safer and cleaner burning. Candles are a source of open burning fire in your home and should only be used with extreme caution any way. Don’t burn them for hours on end; extinguish the the flame after one hour, and allow the candle to cool completely before relighting. Don’t burn candles unattended, and make sure the wax is properly contained as the candle burns down.


Once you find and remedy the cause of your soot stains, it’s time to begin the cleanup job. A variety of consumer-grade cleaners are available that claim to clean up soot stains. They’re certainly worth a try, but commercial cleaning products and a professional cleaning team may be in order, followed by repainting and replacement of carpeting and furnishings in extreme cases. While soot damage is sometimes covered by your homeowner’s insurance policy, the company will generally investigate the cause of the soot. Insurance policies often cover a “sudden occurrence” event – such soot caused by a kitchen stove flareup – but won’t necessarily cover damage that’s occurred over a long period like that caused by candles. Chemical analysis of soot can determine whether it’s caused by an improperly vented fireplace or by candle wax, so expect large cleanup claims to be investigated thoroughly.


Make sure the venting system is properly designed for the appliance it services

Have all fuel burning appliances cleaned, tuned and maintained annually for optimum performance and efficiency

Have all chimneys and venting systems inspected annually and cleaned when needed to eliminate excessive buildup

Use candles with extreme caution

Install smoke and carbon monoxide detectors in your home

Carbon Dioxide in your Office

Carbon dioxide is a villain in the climate change narrative, but coal plants and factories aren’t the only places that produce it. Humans generate CO2 too, just from breathing. And in certain circumstances, that human-generated CO2 might be enough to impair decision making and overall performance at work. Oddly enough, the problem may be especially prevalent in some energy-efficient buildings.

In a study published in Environmental Health Perspectives, researchers from Lawrence Berkeley National Laboratory and SUNY Upstate Medical University exposed 22 people to various levels of CO2 (600, 1,000, and 2,500 ppm) in an “office-like chamber” for two-and-a-half-hour sessions over the course of a day.

The researchers tested subjects’ decision-making ability with something called the Strategic Management Simulation–a system where participants are given real-world simulation scenarios and asked to respond using a drop-down menu of decisions. Factors measured include flexibility in approach, number of actions taken, opportunistic actions, openness to information, and focus on multiple task demands.

Much to the researchers’ surprise, decision-making abilities started declining significantly at exposure to 1,000 ppm–prior to this, the researchers thought detrimental effects wouldn’t start happening until exposure to at least 10,000 ppm. The exposure that the participants received is fairly common; it has been found in elementary school classrooms in California and Texas (21% of Texas classrooms have a peak CO2 concentration of over 3,000 ppm). Office spaces don’t face the same exposure–one study mentioned in the report of 100 U.S. offices found that only 5% had peak indoor CO2 concentrations of over 1,000 ppm.

But here’s where it gets weird: Energy-efficient buildings may be more at risk of having elevated concentrations of CO2. That’s because poor ventilation is one of the primary causes of elevated CO2 indoors, and lowering ventilation rates can cut down on energy use. As you might imagine, that could cause CO2 levels to rise and decision-making abilities to be affected–even, say the researchers, if air cleaning systems are put in place to combat other pollutants.

The researchers explain in the paper: “It seems unlikely that recommended minimum ventilation rates in future standards would be low enough to cause CO2 levels above 2,500 ppm, a level at which decrements in decision-making performance in our findings were large, but standards with rates that result in 1,500 ppm of indoor CO2 are conceivable.”

In other words, future energy-efficiency standards need to take into account indoor CO2 levels just as much as they consider cutting down on energy use–and as a result, outdoor CO2 emissions.

Wet Basements or Crawlspace

An unfinished basement or crawl space can be quietly undermining the integrity of the home and life within it. The crawl space—like many unfinished basements—tends to be quite humid. The excessive moisture in a basement or crawl space poses a number of threats to the home. It provides an environment for mold to thrive—mold that can eventually make its way up into the rest of the home. The moisture can also attract wood-boring insects that destroy the wood sub-structure. The presence of insects may also draw rodents and other pests into the crawl space. Solving the basement or crawl space moisture issue is the first priority in a finishing project.



Moisture Mitigation: Vapor Barriers and Encapsulation
The elimination of moisture and reduction of humidity in the crawl space is crucial to a healthy home. This step will help control mold growth, wood rot and insect infestation, which can also alleviate any rodent issues. Reducing moisture can put an end to any mustiness or unsavory smells emanating from the area. It will also prevent the hardwood floors above from warping.

Moisture and humidity in the basement or crawl space is partially the result of water evaporating from the soil. To combat moisture in the basement or crawl space, a vapor barrier or encapsulation system can be installed.

An encapsulation system usually sees a moisture/vapor barrier or “liner” installed up the walls of the basement or crawl space and over the exposed earth floor. Proper installation methods of an encapsulation system will vary from climate to climate and are dependent on the specific products used, but it often includes overlapping the liners of the wall and the floor, taping all the seams and fixing the barrier to the foundation walls with anchors. The nature of the vapor barrier itself will vary by installer—some use products from outside manufacturers and some have their own patented and branded system. Vapor barriers differ in composition, thickness, strength or durability and color. Thickness can range anywhere between three to 20 millimeters; both puncture strength and tensile strength are rated—these are measured in pound-force (lbf). The type of barrier used should be taken into consideration by the homeowner and can be determined by the desired end result.

One of the most important features of the vapor barrier is the water vapor permeance—or “perm”—rating of the product. This measures the transmission of water vapor through the product. The lower the number, the better the product’s resistance to vapor transmission.  Homeowners should ask TP Environmental which products would be used in a crawl space finishing project.

Just installing a vapor barrier most likely won’t be enough, however. TP Environmental may recommend installing a drainage system along the perimeter of the crawl space walls and a sump pump to keep the ground beneath the liner dry. Leveling the dirt floor will be an option or a necessity, depending on whether or not the homeowner wants to pour a concrete floor, a more expensive crawl space finishing solution. A level crawl space is more conducive to storage usage and will decrease the chances of tearing a hole through the liner.

Some crawls spaces need a lot of work. Fiberglass insulation may need to be removed and replaced. Broken or leaking pipes, drier vents and other elements found in the crawl space may also be a source of moisture and humidity.  TP Environmental will make sure the end result is a clean, dry and healthy room in the home.

Call us today for an estimate 207-991-0171 or

Indoor Air Quality and Weatherization

If your looking at having an energy audit or weatherization project for your home here are a few questions to ask….

1.  Will I need an air exchanger system to overcome the sealing from the weatherization of my home.  Cost for a standard air exchanger system $2000 – $3000.

2.  Will you perform backdrafting testing on my home after the weatherization.

Unchecked, a tightly sealed house can present a flurry of problems, such as range hoods and clothes dryers creating negative pressures in houses large enough to backdraft furnaces, water heaters or fireplaces. The concern then becomes that this can introduce carbon monoxide and other deadly gases directly into the house.

Carbon monoxide (CO) is called the silent killer or the silent threat. This is because it is colourless, odorless, and silent. It is formed as a by-product of combustion of carbon-based fuels such as natural gas, propane (LPG), coal, coke, furnace oil, kerosene and wood. Carbon monoxide is absorbed by breathing and is 245 times more absorbent to the body than oxygen. Symptoms of poisoning can be mis-diagnosed as flu since they are very similar.

Symptoms Carbon Monoxide Poisoning

  • Persistent, severe headaches
  • Dizziness and blurred vision
  • Nausea and vomiting
  • Confusion, weakness of muscles
  • Insomnia and constantly tired
  • Chest pain
  • Fainting
  • Cherry colored skin

The appliances that can generate CO within your house are the furnace, boiler, water heater, un-vented fuel burning heaters and solid fuel burning appliances. The three main problems are improper installation, chimney or vent blocked by bricks or bird’s nests etc. and inadequate ventilation, providing insufficient air to properly fuel the combustion process.

In addition to the symptoms of illness, a number of other signs can alert you to the presence of carbon monoxide in your house. Although carbon monoxide is problematic to detect, a stuffy, stale smell in your house may be a warning of its presence and not necessarily an indication that you should clean out the closets. If you have already taken measures to reduce moisture in your house, and you still see dripping water condensation on your windows, carbon monoxide may be present in your home. Moreover, closely inspect your stove to see that the normal blue flame you get upon ignition has not been replaced by a yellow burner flame. Or, if the pilot light in your furnace continues to go out, turn off the suspect equipment, evacuate everyone from the house and call a licensed heating contractor. A close inspection of your house may reveal that the source of carbon monoxide comes directly from your stove, fireplace, furnace or even your car. Although you would not know it, it is possible that your appliances have not been installed properly.

When your home is too airtight, dangerous carbon monoxide gases begin to seep into the air without you being aware of it. Like you, your house needs to be able to breathe. Excessive weatherizing has the potential to block the necessary flow of air needed for the safe operation of all appliances and heating equipment. Clear the air in your house with proper ventilation, know the dangers of excessive weatherization and don’t give carbon monoxide the chance to harm you and your family.

Maybe a little energy loss is worth good air quality……