Improper Operation of a Crawlspace

Over the last few weeks, I’ve focused on the sealed crawlspace and what goes into one. This week, I will review why you shouldn’t leave a crawlspace open and what is not a proper solution to a vented crawlspace. The reasons for sealing a crawlspace have already been discussed in the previous post; however, here's a review of what a vented crawlspace will typically have:

1. Higher moisture content in the wood
2. Increased fungal growth
3. Higher relative humidity
4. Overall less energy efficient for the home
5. The need for more pest control
6. Lower indoor air quality in the home

Since most homeowners know about these issues, some are looking for alternatives to the sealed crawlspace. While there are possibly individual solutions to each one of these problems, none of them solve the problem like a sealed crawlspace.

There is one solution - the foundation fan - that I have seen used  time and time again in an attempt to control moisture. However, it not only fails to eliminate the problem, but will actually increase the issues in the crawlspace. There are several variations to this product, ranging from simple humidity-controlled fans that install in the vents to larger, more powerful fans that are run on timers. Most individuals will sell these fans on the premise that the crawlspace needs more ventilation to “dry” the space. This is the concept on which the foundation vent was based: By providing ventilation under a home, you are able to keep it dry. Here in the South, this is not the case, especially since we began installing plumbing and HVAC in the crawlspace. By exposing the crawlspace to the exterior air and having surfaces in the space with lower temperatures, you are just providing an optimum situation for condensation.

Condensation occurs when the temperature of the surface is below the dew point of the air. This is the same thing as dew in the morning. When we have surfaces such as plumbing pipes and ducts that will consistently be below the dew point of the outdoor air, we will get condensation of these surfaces. This condensation can wet the other surfaces and cause even greater problems.

Wood surfaces can also be affected, and since fungal growth can occur with a humidity over 60%, you increase the risk of providing an environment conducive to growth when introducing the outdoor air. This brings up another aspect of introducing outdoor air, because as you lower the temperature, the relative humidity rises. We can all assume that the crawlspace will typically be cooler than the outdoor air in the summer time, so as the outdoor air comes into the crawlspace, you will actually increase the air's relative humidity.

Originally, the idea of a foundation vent fan was to increase the ventilation of the crawlspace; however, all it does is actually increase the moisture content of the space by pulling in more exterior air. Therefore, the fan actually increases the relative humidity and the potential for condensation. Many will argue that the air will help remove the condensation, but as you lower the temperature and raise the humidity, you will actually decrease the amount of moisture the air can even hold. Adding more moisture to it will only increase the dew point temperature. There are several cases I've seen in which a vent fan has been installed to combat a small amount of fungal growth, and actually ended up causing the floor structure to rot!

So, if someone tells you that a sealed crawlspace is a bad idea, and that you should instead install a foundation fan, take the time to consider the negatives.

Reduce your air leakage.

If you have a leaky home, think of it as spilling money through the cracks. Most of your loss is through the ceiling, so start looking there first. Seal all ceiling penetrations you can; these include recessed lights, attic stairs, and even standard lights. Next, look to your walls and floors. Last should be your outlets, as they only account for about 2% of the leakage in your home.

Need help finding the leaks? As a homeowner, you can feel for drafts, use a candle, or have a professional set up a blower door.

What Goes Into Sealing a Crawlspace?

Last week I discussed why to seal a crawlspace, so how about now looking at what goes into properly sealing the space? There are a large number of variations on how a sealed crawlspace is installed; while most just vary by quality, not all of them are proper. A sealed crawlspace is intended to provide 5 things:

1. Moisture management
2. Pest control
3. Combustion safety
4. Fire safety
5. Radon safety

There are a few items that are required to make sure your crawlspace is properly sealed and that you will get all the benefits that are intended:

1. Installation of a vapor barrier with sealed joints on the floor, piers, and foundation walls.
A minimum of a 6-mil vapor barrier should be installed, with all joints sealed via mastic or an approved tape. It is highly recommended that a higher mil plastic be used because the 6 mil will tend to tear and wear easier.

2. Seal all foundation vents.
No vents or openings to the outside should be present, other than an access door. Porch penetrations should also be sealed with an access panel or permanent material.

3. Provide a foundation drain.
A foundation drain is needed with a backflow preventer. It is a good idea to allow the drain to accept moisture from above and below the vapor barrier.

4. Insulate the floor or foundation wall.
Insulating the foundation wall is more efficient, but either the floor or wall is acceptable. Evaluate the situation and choose accordingly.

5. Air seal duct and floor penetrations.
Air sealing the ducts will help improve your home's efficiency, and sealing them and the floor penetrations help prevent air transfer between the home and crawlspace. This also helps with fire safety.

6. Vent appliances to the exterior.
Gas appliances should be direct vented or two-pipe vented in the crawlspace. Most vented spaces do not have enough makeup air for single vent appliances, and a sealed one definitely won’t. Direct venting is recommended.

7. Mechanical Moisture Control
There are several variations on this, including the use of HVAC ducts and dehumidifiers. If an HVAC supply duct is to be used, a backdraft damper is needed and no return ducts. This can affect the efficiency of the system, so check with an HVAC contractor prior to doing it. I tend to recommend a dehumidifier, as it is the least problematic.

Additional Item:
A relative humidity monitor is good addition to help you know that the system is operating properly!

Use CFLs!

This is pretty rudimentary when it comes to energy savings, but there are still a lot of people who are not aren't doing this! Incandescent bulbs convert 90% of their energy to heat and only 10% to light, so they are good heaters but poor light generators. CFLs not only use less energy, but they last longer, too. A 14-watt CFL is equivelent to a 60-watt incandescent. The CFL uses around 75% less energy, and therefore costs 75% less to operate. Also, because the CFL lasts 10x longer, you buy one CFL for every 10 incandescent, which increases your savings. Many will argue that you can't use a CFL everywhere, but they are also becoming more versatile in their uses. So look at your light use and install CFL’s where you can!

To Seal or Not to Seal, That is NOT the Question!

There are still individuals in the construction industry who will question a sealed or conditioned crawlspace, but this argument should be put to rest: Studies have shown significant improvements in a home's efficiency and environment with the installation of a sealed crawlspace! According to a study conducted by Advanced Energy, sealed crawlspaces, when properly installed, will perform better with relative humidity, wood moisture content, and energy efficiency than a traditional vented crawlspace.


The study has shown that during the summer of 2003, the studied sealed crawlspaces only exceeded 70% relative humidity only 5% of the time, while the vented crawlspace stayed above 70% almost all the time. The wood moisture content in the sealed crawlspace stayed below 12% during the study, while the vented crawlspace wood moisture varied greatly. Also, the sealed crawlspaces showed an annual energy use reduction of 15% for sealed crawlspace with insulation on the floors and 18% for sealed crawlspace with insulation on the foundation wall.

Here are some of the main benefits to having a sealed crawlspace:

1. Improved Moisture Control
A sealed crawlspace improves the moisture content of the space by preventing transfer of moisture through three of the main entrance points, the foundation wall, the soil floor, and the foundation vents.

2. Pest Control
By removing moisture from the space, the appeal to subterranean termites is reduced.

3. Improved Efficiency
As already stated from the study, results a sealed crawlspace can improve the efficiency of the home.

4. Improved Indoor Air Quality
A good number of contaminates can come from your crawlspace. By cleaning up the space, you may be able to improve the air quality of your home. A sealed space can reduce the mold content in the crawlspace and can be used or modified to prevent radon intrusion.

5. Improved Maintenance
This is an unintended benefit, but due to the increased visibility and improved environment, homeowners are more likely to “visit” the space, leading to better home maintenance. Also, if the insulation is installed on the walls, the floor structure is visible and individuals are more likely to find problems around plumbing or HVAC.

Increase your ceiling insulation.

Most of your heat loss is through the ceiling of your home; by adding insulation in the attic, you can save energy. Insulation in the attic is relatively easy to install when compared to insulation in other areas, and it can have a greater impact. Here in North Carolina, we are required to have R-30 insulation in the ceilings, but I can see a benefit by increasing this to R-38 or beyond. Be careful, though - there will come a point in which the cost of the additional insulation will not outweigh the benefit of installation!


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Top 5 Findings on a Home Inspection

I have found there to be little information available regarding the most common findings during a home inspection. While there are some Top 10 lists available, the ones that I have found are only general, listing such categories as minor structural repairs, plumbing leaks, or grading/drainage problems. To be honest, these general categories are not Top 10’s, but rather a summary of what the home inspector will be looking for during the inspection. When performing an inspection, though I will be looking for items that fall into each one of the categories mentioned, I don’t find that providing this list to the homeowner is very helpful. If everyone knew what to look for within these categories, then the person buying the home wouldn't need to have a home inspector to perform the inspection! In realization of this, I have compiled a Top 5 list from my experience that are relevant to the homeowner.

1. Improperly operating interior doors.
This is typically a door that rubs slightly on the jamb or drags the carpet. It is usually a minor repair and is caused by an improper installation, settling, or installation of new flooring. The door is usually easily repaired by trimming or shaving the door slab.

2. Rotten or damaged trim.
This can be anywhere around the home, but the most common problems tend to be around exterior doors that are on the ground or not covered, such as a garage or deck entrance. Repairs vary from replacement to repair in some situations. 

3. GFCI is not working properly.
Surprisingly, this item actually comes up a lot. While it is a simple fix, most individuals do not realize that the safety feature on their electrical system doesn't work, or they would have repaired it. These outlets are in place to prevent an electrical shock, but if they don’t trip, this can’t happen. The solution is typically a new outlet.

4. Improperly operating garage door opener.
This is another home safety feature gone awry. Most of the time, the problem is the pressure feature that will return the door if something is under it, but sometimes the sensors that return the door if something has crossed under it are not working either. This is typically a simple adjustment or sometimes replacement of the motion sensors.

5. Fungal growth in the crawlspace.
This item can be a discussion all of its’ own, but it is still one of the most common findings in my area of the country. To keep things simple, because the crawlspace is exposed to the environment and has conditions that are conducive to growth, it may have mold in it. How this affects the home and should be treated is again a discussion all of its own and too long for this brief explanation. Repairs for this item will vary significantly based on the scenario.

Replace your old Christmas lights with LED lights

The holidays are upon us, and as the many Christmas trees begin to go up over the next few weeks, everyone can save a little money by using LED lights. If you are anything like me, you have a few strands that aren’t working anyway, but yet you still fight with them every year - trying to find that one bulb that will make that strand work! While savings may be short-term and worth a small amount, they are still savings, and the new lights will last for years to come. Savings will be even greater for all the individuals who take the time to dress the entire home in the festive spirit by placing lights on every eave, doorway, tree, and bush around their home. To all those individuals, thank you for making my holidays a little brighter - both figuratively and literally - as I am still a kid at heart, but take the time and do yourself some good by getting those LED lights.

How Can Saving Water Save You Money?

Often, many homeowners  - and unfortunately, some energy auditors, as well - overlook the benefits to reducing water consumption in the home. Just like reducing your electrical needs, reducing your water needs can also save you money. The benefits you will receive by reducing your water consumption will vary depending on how you receive your water, but ultimately, there are benefits no matter what the situation!


If you are on a well, you may not see the same, direct monetary benefits as someone who pays for their water. However, there are still benefits, primarily in the form of reduced energy consumption through reduced pump use. If you use less water, you will use less energy. Also, in times of drought, you may be able to make it through without your well going dry, saving you the cost of drilling another well.

There are several areas in the home where you can reduce water use, and some of the reductions are by habit alone. Here are some tips for the water-using rooms of your home:

Kitchen:

• Use the dishwasher instead of hand washing dishes. This may sound counterintuitive, but this does reduce water usage when washing full loads - according to the EPA, as much as 5000 gallons a year!
• Install a low flow aerator on the kitchen sink.

Laundry:

• Wash full loads of clothes only!

Bathroom:

• Get rid of the old high volume toilets. Old toilets used 3.5 gallons or more per flush. These can be replaced with low volume or even dual flush. Don’t want to spend the money to replace the toilet? Look for tank flush valve that converts an existing toilet to a dual flush.
  
• Install an aerator on the bathroom sink.  
• Install a low flow shower head. Old units can use over 4 gpm. Newer units can help reduce flow to 1.5 gpm without sacrificing power and comfort.

Yard:

• Don’t use :"set-and-forget" yard sprinklers. These are the ones that you always set in the yard and leave for hours at a time while you are doing something else. These will overwater the yard and waste your money, not to mention make one section of your yard greener than the rest! Consider automated sprinklers or timers. 
• Use rain or moisture sensors on sprinklers. For those of you who do have automated sprinklers, make sure you have moisture sensors on your units so they don’t come on in the rain or directly after one. Let Mother Nature do her job! 
• Use rain barrels to collect your water for indoor and potted plants.
• Use spot watering or soaker hoses for your gardens. If you’re not watering by hand, use direct watering means for your plants in the garden. These can be either be soaker hoses or drip irrigation directly at the base of the plants, which eliminates unnecessary watering of the soil (which promotes weed growth, anyway).

Set hot water temperature to 120 degrees.

Setting your water temperature over 120 degrees can not only cost you money, but it is also a safety hazard. We do not typically use the full temperature of our hot water, so why pay to heat something up when you are only going to cool it down?

Basics of Mold Testing

Once you have had your home tested by a professional, how do you determine if the results are accurate? Hopefully, you have hired an ethical professional who has the proper training and expertise to perform the testing; just in case, as a homeowner, you should have a little understanding on how to interpret the sample results.

While there are several different types of samples used in the industry - and just as many sampling devices - two kinds of samples are the most common. These are the non-viable air sample and the surface sample.

Non-Viable Air Samples
The non-viable air sample is collected by pulling a known amount of air over a sticky slide. Contents of the air are deposited on the slide. This includes mold spores, insect parts, fibers, and anything else in the air. Some labs report on the other contents of the slide, while some only report on the mold. Several things can be inferred from the additional contents, but to keep this simple, we will concentrate on the mold spores.

The spore counts will be listed in the number of spores of a category, spores per cubic meter of a category, total spores, and total spores per cubic meter. The number of spores is the actual number of spores on the slide, while the spores per cubic meter is derived from a formula based on the amount of air pulled over the slide.

Both findings are important along with the location of the samples. An outdoor control sample should always be taken, and an air sample should never be taken in an unoccupied zone such as an attic or crawlspace. The sample taken from the investigated area is to be compared to the control sample.

There is a lot to interpreting non-viable spore samples, and a homeowner cannot be expected to understand all the aspects of the testing. A lot comes from experience and dealing with a large number of samples. I always recommend that you remember the following and don’t be afraid to ask questions or even another opinion:

1. In most situations, spore counts in the home should be similar to or below the outdoor control;
   
   
2. The type of mold spores in each sample should be similar;
   
   
3. Variations in the samples can occur, but this doesn't necessarily mean there is an abnormality in the home - you must look at the amount and type of spore in the variation;
   
   
4. Just because spore levels in the home are higher than outside does not mean there is a problem - levels must be considered significantly higher to cause alarm;
   
   
5. Actual counts of spores should also be considered - one spore in the sample can read as 13 spores per cubic meter or more, depending on the amount of air passed over the slide when the sample was taken. One spore may not indicate a problem!
   

Surface Samples
I have found surface samples to be one of the most misused samples out there. A surface sample can be used to determine the type of mold present, or if there are a large number of spores on a surface due to cross contamination. However, many people have been using surface samples to indicate abnormal fungal growth. This should not be the case if mold is visible.

A surface sample can be taken using a swab, tape lift, or stick slide. All are proper methods of sampling; the only difference is how you record the area sampled. The area sampled is only in question when quantitative results are desired; in most cases, the samples are qualitative and only used to determine what type of mold is present.

How results are reported vary by lab, but most use a scale, such as "occasional, few, moderate, numerous." Wording and categories may change between labs, but in this case, "occasional" and "few" would be viewed as normal, while "moderate" and "numerous" would be viewed as abnormal. The scale is typically listed at the bottom of the results.

Here are some items to remember when reviewing surface samples:

1. Surface samples do not indicate how much growth is present on a surface, just in the sampled area;
   
   
2. For the most part, surface samples are only for mold identification;
   
   
3. All surfaces may contain some amount of spores, even if everything is normal;
   
   
4. Generally, surface samples should not be used to determine abnormal conditions or remediation protocol.

The final item of this list is the most important, and should be further explained. The best example that can be given is as follows:

There are two walls in the home, Wall A and Wall B. Wall A has one square inch of mold on it that is very dense, and Wall B is fully covered (80 square feet for an 8x 10 wall), but it is not very dense. Two samples are taken from each wall. The results from Wall A come back with "Numerous" spore levels for one genius of mold, where Wall B comes back with "Moderate" and "Few" spore levels for several genera of mold. According to the samples, Wall A has a problem, while Wall B does not. Someone could determine based on the samples that Wall A needs remediation more than Wall B. In actuality, Wall A has had all the mold removed by the sample, while Wall B has a significant problem. The variation comes from the density and area sampled.

This just gives a rudimentary example of why surface samples cannot be used to determine the need for remediation. I see this happening the most in crawlspaces, with recommendations being made over the density of the growth - not the actual coverage area.

With surface samples, only take them for what they can actually tell you. Again, as a homeowner, don’t be afraid to ask questions or get a second opinion!



Install weather stripping.

This may seem like a simple item, but many people forget about it. Check around your windows and doors and see if they are leaking, or if you can see daylight. If so, install weather stripping to seal this up! There are various types, and each one has it use. Ask someone at your local hardware store which one works for your situation or you can research your options online. Also, while door socks can help, many people will remove them in the summer. Just because you are not uncomfortable in the summer with the draft under the door, it's still there and costing you money! If you do this, also remember to pick up a door sweep while you are at the store getting your other weather stripping supplies.

How Do I Prevent Mold?

This is a very common question among homeowners. Concerns for fungal growth or mold often arise when an unfamiliar odor is noticed or a small leak occurs, and at that time one starts to investigate how to prevent the growth from occurring! I am often asked if there is a special treatment or construction product that can be used to prevent fungal growth in the home. While there are products on the market that are resistant or retard growth, there are even simpler solutions to prevention.

Before even looking at how to prevent fungal growth, what must first be understood is whether mold is ubiquitous to the environment. No matter what we do, we cannot keep mold spores from being in the air! It is the nature of our world and part of the air we breathe. With the understanding that these spores are everywhere, we can look at how to stop them from growing. In order for fungal growth to occur, there are four items that need to be present; removal of any of the four will prevent growth:

1. Mold Spores
Common sense would prompt the thought that for if spores are everywhere, then why even discuss this? Of course, spores are one of the four items that are required for growth, and there is little that can be done to prevent them from being in the air. What should be understood is that if you have some growth in the home, remove it - you don’t want to increase the number of spores that are there. I have had several individuals ask if they could just leave the mold growth if they removed one of the other three items required for growth; the answer is no. If you leave the growth, you have left spores on the surface; if you reintroduce optimum conditions for growth, you have just created a bigger problem because there are more spores present than under normal conditions. The bottom line is that you can do little to prevent the number of spores in the home; however, if you have growth, no matter how little, remove it before you just create a bigger problem if the conditions that are conducive to growth become favorable.

2. Temperature
This is the one item that is hard to control, and in all actuality, you really can’t. Though there are some species of mold that like to grow outside of our comfortable temperature range for living, many grow in the same temperature range that we like to inhabit, so there is not much that we can do. I am often asked if someone can cool or heat a home to help with the growth. There is some possibility to this, but often the range that inhibits (or prohibits) growth is out of our comfort range, so this is difficult to do.

3. Nutrition Source
Like all living organisms, fungus needs something to "eat" to grow. This comes down to organic material, which is often drywall paper and wood in our homes. Things that are not organic and will not support fungal growth for the most part are bricks, stones, and fiberglass. These objects do not have nutritional value for the fungal growth, and for the most part will not support it. However, dust and dirt collected on these items can have nutritional value, so there can be an exception to this rule. If we build our homes primarily out of material that supports growth, how do we eliminate this item? For the most part, we can’t, but this is where all the new materials on the market can help, such as fungal-resistant wall board and the variety of products that have Microban as a component. We can limit the nutritional value in the products we use, but again, this is something that comes along with the construction of the home, so it is less of a preventative measure in older homes.

4. Moisture
This is the most preventable of the four items in preventing fungal growth from ever occurring. Stop the moisture in the home! If you have a water leak, correct it and dry out the area. If you have water intrusion through your basement wall, stop it. Plain and simple, keep your home dry. Most homeowners understand this and do well with stopping the large water intrusions. Some of us could do a little better at doing maintenance inspections to find leaks, but again, for the most part, active leaks are typically corrected. Sometimes catastrophic damage occurs from a water line breaking or when piece of equipment malfunctions, such as a dishwasher. This cannot always be prevented, but there are items on the market that can help reduce the likelihood of the damage being significant, as well as good practices with preventive maintenance.

The one moisture source that most homeowners overlook is humidity. We all know how high humidity affects us, especially in the south, but mold likes a relative humidity above 60%. If your air conditioner is not properly operating and removing the moisture from the air in the summertime, or even in some cases putting more moisture into the air, you can have a mold problem without ever having water damage. The solution to this is to monitor your relative humidity and make sure the air conditioner is functioning properly.


Install a Radiant Barrier

A radiant barrier in your attic does not add to the insulation value of the attic, but it does help manage radiant heat. Radiant heat is the warmth we feel when standing in the sunlight. In the summertime, we want to keep this out, and in the wintertime we want to keep it in. Depending on the installation of the barrier, you can achieve both of these functions and reduce the heating and cooling cost of the home.