Due to popular demand, I have been forced to sit down at my computer and put
to paper my mold prevention ideas and concepts that apply to finishing basements
and other sub-grade living spaces.
First, let me say that if you are reading this you are head and shoulders
above the mass of the population that will haphazardly sheetrock and
carpet a basement without concern for the inherent problems that traditional
finished basements are known for within my industry. My only concern
is that the ideas contained in this article gain wide acceptance and
my revenue decreases dramatically. If this occurs, I will gladly accept
generous donations from the happy applicants of the wisdom contained
herein.
Few of these ideas are original. The true value of this short piece
is to shine the light on the choices you have as you endeavor to add
very valuable space to your home.
If done right, a nice profit and many enjoyable years can grow out of
your healthy, well-designed basement. If done wrong or without proper
attention to the crucial details, other things will grow out of -- and
in -- your basement. And you won’t like that. That’s why
you are reading this. So let’s proceed.
Let’s start with a brief course in mold. Mold 101. Here’s
all you need to know for now.
Mold spores are like microscopic seeds that are constantly floating
around in the air. In fact, unless you are highly sensitive or there
is a large concentration of spores as a result of a mold growth problem
near where you are now sitting, the air you are now breathing contains
mold spores that are probably not bothering you in the least. Mold spores
are literally everywhere; on your clothing, your eyeglasses, the face
of your watch, your kitchen table. This is unavoidable. What we really
want to avoid is mold growth, not mold spores since mold
spores are, in fact, unavoidable.
Why do you not want mold growth in your house? In a nutshell, here it
is:
It stinks
It ruins your stuff
It can make you and your family sick
Other nasty stuff likes to join the party (i.e.
dust mites, spiders, bacteria, amoeba, nematodes)
You may end up having a hard time selling your
house
Mold growth occurs when a few specific factors are present. In fact,
part of the problem is that these factors are very often present indoors
because mold loves the same conditions we do, with few exceptions.
Of all of the above factors, moisture is the most easily controlled.
In fact, few of the other factors are easily or cost-effectively dealt
with. So, control moisture you must. Moisture control is the mold-prevention
mantra.
Also at play is the type of building materials and the way they interact
and integrate in modern construction. The way we have built and continue
to build homes since the 1970s energy crisis, and what we build them
with, makes it very easy for mold growth to occur indoors. Most builders
use low-cost materials, over-insulate and insist on putting basements
into buildings built in areas with poor soil drainage or high water tables.
One of my mentors is fond of saying that we now build self-composting
houses – just add water!
When it comes to finishing basements, you have more choices and – at
the same time – more problems. Since it is a much smaller space
than the rest of the structure, you can spend more money on the specialized
building materials that resist moisture and mold growth. At the same
time, the added cost can sometimes make it more expensive than it’s
worth for some homeowners. For example: Dens-Armor Plus by Georgia-Pacific,
a fiberglass-faced gypsum board with no mold-friendly nutrition source
for the mold to grow on is at least 2x the cost of normal 1/2” paper-faced
drywall gypsum board. In fact, many of the solutions are twice the price
but worth every penny. The way I figure it, you can spend twice as much
once and do it right, or you can do it wrong and spend half as much,
but end up doing it twice. The first choice is must easier, and you don’t
have to pay a mold remediation specialist a small fortune to gut your
basement and a remodeler to rebuild it all over again. Look at the savings!
In addition to donations, I accept Thank You cards. This means you can
thank me for saving you tons of money in advance. Tons. I
really like the Thank You cards. I still prefer donations though.
Moving on.
Here are the primary ideas and guidelines to follow:
1. Stop the water: If you have a damp basement or get water sometimes,
you MUST do whatever is necessary to fix it before doing anything else.
A dehumidifier is NOT the silver bullet. If you can, you should do whatever
you have to do to prevent the water from coming into the basement in
the first place. This can sometimes mean excavating outside, fixing cracks
and sealing the foundation properly (Big $$$$). Although still expensive,
some people install French drains (see more on them later) and sump pumps
with battery backup units. This can be helpful but, again, it is not
a silver bullet all by itself. You may find that something as simple
as re-grading outside, covering window wells or extending the gutter
downspouts further from the foundation is enough. You may find that some
combination of these may work. In any case, do what you must. Otherwise
your allergies and your wallet will suffer.
2. Monitor the humidity with a digital humidity gauge otherwise
known as a hygrometer (available at Radio Shack, Lowe’s, etc. for
about $20). Keep your humidity at 45% or below. In fact, you should do
this in the other areas of your home as well. Maintaining a moderate
humidity in your home is one of the most important things you can do
to keep your home healthy and help prevent mold growth, dust mite proliferation,
and a whole roster of other nasty stuff. In the basement, do not even
think about finishing it until you get a handle on the humidity.
3. Insulate all cold water pipes to prevent condensation. When
possible, insulated ducts are a great idea too to prevent condensation
from accumulating on the ducts in the ceiling when the air conditioning
is running. But this is not always practical.
4. DO NOT PAINT YOUR WALLS WITH DRYLOK OR WATERPROOFING PAINT.
Concrete does not support fungal (mold) growth. Paint does. Even most
antimicrobial and antifungal paints and coatings will eventually grow
mold if the conditions are right. Also, do not attach insulation directly
to the foundation walls. It behaves as a moisture trap and can also hide
structural problems and cracks in the foundation. Bottom line: basement
walls need to breathe too.
5. How ‘bout a little elbow room?: Although this is sometimes
impractical and you can lose a lot of square footage, building the wall
at least 18 inches away from the foundation gives you permanent access
to your foundation and allows enough air movement that ventilation and
dehumidification can work together to the fullest. Also, if you ever
need to perform any repairs to the foundation, it can be done with little
additional cost and destruction. It also makes upgrading wiring, plumbing,
sound systems etc. much easier and less expensive.
6. Use metal studs or, if you use wooden studs, make sure to
put in a pressure-treated sill plate. As a rule, untreated wood and all
porous and absorptive building materials should never be in direct contact
with concrete. A concrete slab and foundation can contains thousands
of pounds of water and will gladly transfer that moisture into anything
porous and absorptive it’s in contact with. Once the moisture gets
in and stays, mold growth and, eventually, rot are inevitable. So keep
wood, drywall, carpet, carpet padding, tack strips, etc. away from direct
contact with concrete.
7. Insulate properly: Although some building code officials do
not like rigid insulation, it is a preferred material for moisture-prone
areas such as basement. Unlike traditional fiberglass batt insulation
that you will find in most attics and wall cavities, rigid insulation
will not absorb water. Also, rigid insulation contains no nutrition to
support mold growth but the paper backing on many kinds of fiberglass
batt insulation does. Building code officials don’t like rigid
insulation sometimes because in the event of a fire, the gases are deadly.
So if that scares you or your local building code official too much,
then fiberglass batt insulation is your best bet. Johns Manville makes
a Formaldehyde-Free fiberglass batt insulation that is great for families
concerned about indoor air quality. You’ll know you’ve found
it because it is white, fluffy and encased in plastic.
8. Heat and air condition the basement just like the upstairs.
Consult with a NASE certified HVAC technician to prevent losing heating
and cooling efficiency upstairs.
9. No carpet. No hardwood floors. Ceramic tile is the preferred
choice. Pergo is often recommended but I have my reservations. Pergo,
as with all laminate flooring, is made by taking fiberboard planks with
decorative laminate sheeting around it. The fiberboard inside is a favorite
on the menu mold likes to eat from most. If you insist on carpet don’t
overspend, seal the slab with an epoxy-based concrete floor sealer, use
no carpet padding, and install Dri-Core (www.dricore.com)
or Sub-Flor (www.subflor.com) raised-floor
systems on the slab. Then put your carpet over the raised floor system.
If you flood, for whatever reason, the carpet will need to be professionally
dried within 24 hours, or it is garbage. Period.
10. No drywall on exterior walls. This includes “green-board”, “blue-board” or
any paper-faced gypsum wallboard. All of it will get moldy in a wet environment.
On exterior walls, Dens-Armor Plus by Georgia-Pacific is the only way
to go. It has no mold-friendly nutrients and is just as easy to work
with as standard drywall. At this writing, the only problem with Dens-Armor
Plus is that it is has a slightly different surface texture when compared
to traditional drywall. It requires more primer and more paint to even
out the surface. When I called Georgia-Pacific to ask them about this
they assured me that they are working hard to remedy this.
11. Get it up: Regardless of the type of wallboard you use, keep
at least a 2-inch gap between the bottom edge of the wallboard and the
slab to prevent wicking in the event of water intrusion or release. Use
molding along the bottom to cover the gap for aesthetic reasons. Do not
let the drywall touch the foundation walls either.
12. Get exhausted: If bathrooms or a kitchen are part of the
plan, exhaust fans vented to the outside are a must.
13. Stuff it: Anything stored in the unfinished areas should
be in Rubbermaid containers or, at least, up on shelves.
About French drains:
1. If you think you have a French drain, you might. But you probably
don’t. Most people were told when they bought their house that
the gap between the wall and the floor around the perimeter of the basement
is a French drain. A vast majority of homes that have this gap where
the floor meets the wall actually have something called a “floating
slab”. It was designed that way for a few reasons. 1. The gap allows
for a very small amount of water to collect in the gap and not get onto
the floor. It should eventually drain, but VERY slowly. The problem is
there is no pitch or slant for the water to follow and so the water just
sits there and then, most of the time, evaporates creating high humidity
or allowing the random debris in the gap to get moldy and decompose;
neither being a good outcome. 2. It allows the floor to “float” slightly
and prevents the cracking that may result from excessive vertical pressure
from rising water under the floor. 3. Every state has different laws
regarding warranties for new home. Homes in NJ come with a 10-year structural
warranty and a 1-year water guarantee. This perimeter gap conveniently
keeps the water off the floor long enough for the warranty to expire
and the builder to get off the hook.
A French drain can be used inside or outside. They were developed in
12th-century France – hence the name – to deal with pooling
and rainwater run-off. Much like the Northeast here, they have a lot
of clay and, as a result, poor drainage. A true interior basement French
drain contains a few elements. There are many bells and whistles but
the guts of it remain the same.
Perforated pipes and gravel under the floor around
the perimeter that are pitched towards the sump pump
pit.
The pipes terminate, or drain, into a pit
The pit has a pump capable of ejecting the water
out and away from the building
If you want to know whether you have a true French drain or not, this
requires some investigation. Here are a few questions to get answered:
Can you see gravel or stones in the gap?
Do you have a sump pump pit with a working pump
and pipes that drain into the pit?
If you pour water into the gap, does it disappear
quickly no matter how much you pour in (think: garden
hose full-blast for 10 minutes)?
Does it make it into the sump pump?
Can you see a “scar” around the perimeter
where it looks like concrete was removed and replaced?
If you have a concrete or cinder block foundation,
are there holes drilled into the block walls all
the way around the perimeter that allow for the cells/voids
within the walls to drain into the gap?
If you answered “no” to more than a few of those questions
you probably have a floating slab. If you want confirmation, open your
phone book to Waterproofing and call a few of them to come and take a
look. Be prepared to endure a sales pitch and sift through the B.S. But
you should be able to find out what kind of drainage you have….or
need.
2. If you have a sump pump, a battery backup unit is a must.
Just think, when do you lose power? During a thunderstorm or hurricane,
right? When do you need a sump pump most? Exactly.
3. Make sure that the discharge from the pump goes far enough
away from the house.
4. If you get an interior French drain installed or are willing
to add to your existing one, a round floor drain tied into it is a great
idea especially in the middle of the floor, in the bathroom, or anywhere
else that flood and spills are probable and likely.
5. This one will make my friends in the waterproofing business
hate me, but you will love me for speaking the truth. Most installers
are crooks. Check the BBB and call at least 3 references. Get an insurance binder,
not an insurance certificate, with your name and address on it BEFORE
the work is started. Do not give more than a 10% deposit and make sure
it is refundable if they fail to deliver the insurance binder. Get everything
in writing and go with your gut feeling. You will probably be right.
6. It is often a high-pressure sales pitch so put on your thick
skin and don’t fall for the scare tactics. Most of the systems
are so similar in design that the main variable is the quality of the
company. Since what you are really buying is a warranty, make sure they
will be there when the system leaks or the sump pump fails. Both will
probably happen at some point.
7. If you really still feel confused…call me.
Oh, and good luck. Remember my first piece of advice…don’t
finish your basement.
But if you insist, at least do it right.
Our Guarantee
If you aren’t pleased, neither are we.
We will re-perform any contracted service
deemed to be unsatisfactory – free of additional charges.
If you are still displeased, we will offer a 100% refund.
We know that you’ll be more than satisfied.
We guarantee it.
