So let’s travel back in time to the 1950’s. The kids are bringing home friends and, well, mom needed to find a place for the kids to go. Someone figured out that the basement is already there, ready for action. Add a little paneling and a couple of weekends work and maybe a pool table, and the kids would have a place to gather. With the possible addition of a six pack, the plan also worked for the adults and their friends. Welcome the basement game room to modern living.
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Sixty years later and the basement is still the cheapest place to add living space to a home. Today’s basements are “not your daddy’s game room” They are now often elaborate and expensive endeavors featuring wonderful products and materials that were science fiction in the 1950’s.
Today there are homes still under construction that are already growing fuzzy mold. Expensive does not mean “free from mold.” This year I have found two under construction homes over $750,000 in sales price that already had mold at an unhealthy level. Start with the normal moisture in building products and add that to “Energy Star” tight construction and you have the perfect petri dish.
As in most things, preparation is the most important place to start a project.
Look for water coming through the wall. White power, yellow stains or black areas on basement walls are the result of water penetration. Fix the cause. Water behind walls will result in mold, termites, carpenter ants and rot to materials. It is also easier to locate and correct the water problem before walls and ceilings are installed.
Test for moisture coming up from the floor. The simple trick is to securely duct tape the perimeter of an 18”X18” piece of clear plastic to the floor. Come back in 3 days. Look at the plastic. If water droplets have collected under the plastic, the water problem under the floor needs corrected before moving forward
Test for radon and natural gas leaks before finishing the basement. In addition to making the basement a healthier environment, it will be easier and often less expensive to fix before the basement is finished.
Move water and gas valves so that they can be used. They are installed for a purpose. You do not want to learn that purpose when water is running through a wall or ceiling.
Plan for all of the features you want in the room. Your plan should include any future changes that may happen in upper levels. Installing plumbing, wiring and heating for a future bath or other renovation will be easier when you have basement access.
Check local codes. As one example, many codes and municipalities require the installation of a second method to exit the home from a finished basement. There are manufactured large window and window well assemblies that allow people another path to leave the basement. Many appraisers can’t add the value of a basement space as living space without that additional exit. Adding that feature can add thousands of dollars to the sales price.
Avoid the Most Common Mistakes in Finishing Basements
Allow enough room around the hot water tank and furnace for both servicing and replacement. You will not like your plumber removing a section of wall to change your hot water tank.
Plan your rooms so that electrical panels are not located in clothes closets, bathrooms or stairwells. That is an electrical code requirement.
Allow for floor drains to be located where the traps can be filled with water. Sewer odor is a common problem if a trap dries out under a carpet.
Provide for comfortable heating, cooling and fresh air. Call a professional for that part of the project. Most home improvement contractors and DIYers don’t have the experience or knowledge to make basements comfortable year around.
Add enough lighting. Consider adding enough light fixtures to create a bright environment. Even if you call it a “man cave”, dark rooms are not pleasant and inviting.
Solve moisture problems without adding interior French drains if possible. If an interior french drain is installed, seal the system. Do not install sheet vinyl, not matter how cheap and easy it is to do. These floors trap moisture underneath the surface. The floor then turns gray with stains from moisture.
Modern Tricks and Products for Better Basement Living
Material selection for the basement can make the difference between having an enjoyable family living area in the basement or a dreaded dark and smelly place.
Frame walls with steel studs instead of wood studs. It is not really so scary to use steel studs. They are easy to cut and screw together. They are better in basements because they are not a source of food for termites or mold.
Do not install the new walls directly against the foundation. Allow an air space of an inch between your new walls and the foundation. That air space allows trapped condensate to vent out from behind walls.
Use a wall finish such as fiberglass drywall. Traditional drywall, including MR (Moisture Resistant) board supports the growth of mold. Some of the fiberglass faced drywall products are DensArmor and Greenglass Board.
Raise the wall finish and any wood trim about 3/8” up from the floor. This avoids the wicking of moisture up a wall if a leak occurs.
Select a floor material that is resistance to water breakdown or mold. Some examples would include carpet that is Olefin yarn based as opposed to other yarn systems. Avoid carpet pad. When you think about it, carpet pad is really a sponge that will hold dirt, odors and mold
Read the instructions on all flooring before purchasing. Yes, I know that reading directions is a tough task. An example of why this is important is the popular composite or laminate flooring. Some of these materials specify “not for use in a below grade application.” Others require specialized underlayment or procedures for this use. Ceramic or solid vinyl flooring products such as Traffic Master are examples of good products for basements.
When installing flooring, use adhesive suited for damp areas. Saving money on adhesives can be an expensive mistake
Cover plumbing pipes with foam insulation. Also insulate ductwork if you have air conditioning. Think of the glass of ice water on the table on the 4th of July. Covering pipes is like putting them in a Styrofoam cup instead of a sweating glass. You do not want dripping of pipes and ductwork.
In the end, if a basement is not a comfortable place to go, it has little value. That is unless you want to grow mushrooms in your very own basement cave.
A lack of fresh air is a common problem in finished basements and new energy efficient construction. This is a great article explaining the choice of methods to add the fresh air we need for a healthy home Ventilation is a great thing. Bringing outdoor air into the home and exhausting stale indoor air improves indoor air quality. Well, most of the time anyway. Sometimes the outdoor air quality is worse than indoor air. Sometimes you bring in too much humidity and start growing mold. And sometimes you bring in the wrong outdoor air.
A lack of fresh air is a common problem in finished basements and new energy efficient construction. This is a great article explaining the choice of methods to add the fresh air we need for a healthy home
Probably the most common type of whole-house mechanical ventilation system in homes is an exhaust-only system. You put some controls on the exhaust fans that are already in the home and those fans are set to exhaust stale air from the home, either continuously or intermittently. The problem is this type of system sucks. Literally. And if your house is sucking from an attached garage, a moldy crawl space, or dirty attic, you could be making things worse.
The way to avoid having a house that sucks is to do balanced ventilation. You exhaust stale air from the house and you supply an equal amount of air directly rather than relying on the negative pressure of the house to bring in the outdoor air. Here are five ways to do balanced ventilation. I've put them in increasing order of cost, complexity, and efficiency.
1. Open the windows
OK, technically I shouldn't include this one because it's not a real solution for most homes. This one works only if the home is in a mild climate that needs to little to no conditioning. But if that's your situation, you don't need a fancy ventilation system. Just open the windows.
2. Pair a central-fan integrated supply system with the exhaust fans
A lot of homes get exhaust-only whole-house ventilation (fans plus controls). One easy way to upgrade is to install a central-fan integrated supply system to complement the exhaust-only side. The two most commonly used controls for this are made by AirCycler and Honeywell.
These systems are integrated with the blower in the central heating and cooling system. They bring in outdoor air when the system is running and mix it with the indoor air circulating through the duct system. It gets filtered and conditioned before being introduced into the home. When tied to the exhaust-only controls, you get balanced ventilation.
The main drawback of this system is energy use in systems that don't have variable speed blowers. In addition to bringing in fresh air when the system is heating or cooling, it can turn the blower on when the home doesn't need heating or cooling. And some blowers use a lot of power. Turning on a 400 watt fan to bring in 50 cubic feet per minute of outdoor air is overkill. If you have a high-efficiency heating and cooling system with a variable speed blower, you should be able to do this at less than 50 watts.
And another drawback, pointed out by Curt Kinder in the first comment below, is moisture. In a humid climate, running the blower without the compressor on can evaporate moisture on the coil and put it back into the home.
3. Pair a supply fan with the exhaust fans
Another way to get balanced ventilation is to use the exhaust fans with controls and also install a supply fan. You can do this with a bath fan installed to blow air into the home or you can use a fan made specially for this task. I'm thinking of the QuFresh fan made by Air King.
They have two basic models. One has a sensor for temperature and relative humidity, and the other does not. The purpose of the sensor is to limit the amount of ventilation when it's really cold, really hot, or really humid outside. It'll still run 15 minutes an hour so you'll keep getting some ventilation air.
I like the concept and the features in the QuFresh fan. I haven't had a chance to try one out yet, but they do a lot of good things. You can adjust the flow rate from 30 to 130 cfm. It has a slot for a 2 inch filter that could be up to MERV 13. It's quiet (0.5 sone at 50 cfm). And it's relatively inexpensive.
3a. Pair a ventilating dehumidifier with the exhaust fans
OK. This really should be number 4, not 3a, but somehow I didn't think about it when I put my list together at first. The strategy here is to use controls on your exhaust fans, as in the previous two, and supply your ventilation air through a whole-house dehumidifier. Many models allow you to do this by providing two intake ports on the dehumidifier, the smaller of which attaches to a duct that goes to the outdoors. We like Ultra-Aire but you can also find good models from AprilAire, Honeywell, and others. (Disclosure: Therma-Stor, which makes Ultra-Aire dehumidifiers, advertises here in the Energy Vanguard Blog.)
One drawback of dehumidifiers is the heat they put into your home. The Ultra-Aire model SD12 eliminates that problem by being a split-system dehumidifier. It removes the humidity indoors but puts the heat outdoors. That means it even provides a bit of cooling (about a third of a ton).
4. Use a heat or energy recovery ventilator (HRV or ERV)
This is what most people think of when someone mentions balanced ventilation. The photo at the top of the article shows the inside of a typical ERV. (An HRV looks the same but uses a different material in the heat exchanger.)
The operation is simple. It has two fans, one to exhaust stale indoor air, one to bring in fresh outdoor air. It filters both air streams. The two air streams pass through a heat exchanger, a capillary core in most models. The two air streams pass near each other and exchange heat in an HRV and heat and moisture in an ERV. But the two air streams don't mix.
This is a great way to ventilate a home. It's also more expensive than the ones above. Panasonic does have a small "spot" ERV called the Whisper Comfort, but aside from that model, you're probably looking at $1,000 or more for an ERV or HRV. The biggest difference between this type of balanced ventilation and the previous two is the heat exchanger. You get balanced ventilation with recovery, which means you don't need to do as much conditioning of the outdoor air you bring in.
Finding balance
There's your quick rundown of the main ways to do balanced ventilation. We're seeing a lot of creativity in the ventilation market these days because ventilation is a big deal. I think we've gotten to the point where we rarely have to fight the battle about the need for airtight houses. The old myth that a house needs to breathe, while not completely gone, has mostly been relegated to the dustbin of bad thinking.
One more thing. I was going to make this a list of five ways to do balanced ventilation but decided to save the other one for a separate article. Going a step beyond the ERV, you could go with a souped-up ERV. There are two companies making devices that include balanced ventilation with recovery, a small heat pump, better filtration, and more. One is the Conditioning ERV, or CERV, by Build Equinox. The other is the Minotair by Minotair Ventilation.
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