What is the best way to get rid
of cracks in the walls or ceiling of a house? If you can't get
rid of them, what is the temporary "Fix," and how often must
this "Fix" be done?
Let me respond to the second part of your question first. Your
question about what to do if you can't get rid of cracks in
your wall or ceilings, and how often a “temporary fix” might
have to be repeated, is very important. The reason it is important
is that it gets at the need to determine WHY the cracks are
forming in the first place. Usually, cracks result from a house
naturally settling on its foundation, or periods when you house
may have experienced large changes in temperature or humidity,
etc. Small cracks created by these events can be successfully
repaired and should last for a long time. But if your repaired
cracks end up showing up again in just a few months, getting
bigger, or are joined by cracks in other parts of the wall or
ceiling, then this may be an indication of a bigger problem,
such as: the wood framing in the walls or ceiling may be flexing
due to excessive moisture; or the structural integrity of your
house might be compromised; or that your home needs a humidifier
for the winter; etc. If this is the case, then it would
be best to talk to a building contractor who can diagnose the
problem before more serious damage is done to your home.
Now regarding the first part of your question, the initial step
to fixing a crack in the wall or ceiling is assessing whether
you have plaster or drywall (drywall is also known as sheetrock,
plasterboard, or wallboard).
With plaster, you will need to check to see if the metal lathe
on which the plaster is applied needs to be secured with some
additional nails. The cracks can then be filled with plaster
compound. After it dries, you can sand it and paint the affected
area, and carefully “feather” it out to the surrounding areas.
For repairing drywall wall or ceilings, the patch compound you
will use is called “joint compound” (also sometimes call “spackling
putty”). Applying drywall joint compound typically involves
putting several coats on, and sanding in between each coat.
Use a sanding block to help keep your work flat and smooth.
Sometimes larger cracks both in plaster and drywall need to
have the crack area enlarged to remove loose pieces. This can
be carefully done with a utility knife. A very wide crack will
need more reinforcement to help it stick properly. And this
is where patching tape (also called joint tape) will be helpful.
If the section is very large, then you may even want to cut
back the wall or ceiling all the way back to the middle of the
studs or ceiling joists (the middle of the studs so that you
still have something to nail to), and then adding a new section
of drywall (and then patching the seams with drywall tape.)
One important note is that textured ceilings installed before
around 1979 may contain asbestos, which is hazardous to breathe
when disturbed. If your house is more than 25 years old, you
should have the ceiling tested. And if the test comes back positive,
then you will need to have a licensed asbestos abatement contractor
tell you what your options are. Do NOT work on it yourself if
you suspect that there could be asbestos involved.
We hope this helps.
Lima on 4/27/2008:
My baseboards are mold, bent and squeak by much too low air
from outside. Besides the air flow issue, how can I fix those
ANSWER FROM HOME-WIZARD.COM
ON on 4/27/2008:
Just so that I understand your question, when you refer to your
"baseboards", do you mean the wooden baseboards where your walls
meet the floor? Or are you referring to your baseboard heating
system? Or are you referring to your hardwood floor boards?
And what do you mean by "much too low air from outside"? Are
you referring to an area that is getting wet, and not having
enough air circulation to dry it out?
If you can provide me with some additional information, I can
then give you the best answer.
from Lima on 04/28/2008:
Thank you for your
The baseboard I meant is the board under the carpet sponge,
in this case which is like a big pannel.
What happen was, We installed a new furnace and heat pump, along
with it the installer recomended humidifierto come with it.
It was way too powerful and created extra noise and air leak
from the air hundler(the leak also created a very loud hissing
sound), even though no harm to the house for 5 or 6 months.
When the installer tried to fix the air leak and noise by reducing
the air flow to the lowest stage, I started to notice a mugging
smell, and I turned off the humilifier. Which is also when the
baseboard started to squeak.
But the smell was still there a month later. As the day
passed by the baseboard started to bent here and there so I
could feel the bump on the floor through my feet.
And one day, I happened to find out that the system automatically
set to bring in the out side air every 20 minute for 20 minutes.
In a normal weather or air flow those damage won't happen.
But in this Northwest it rains 24/7 and the humidity is most
likely more than 90 percent. Atop of that the Forced Air
flow was so low and won't be able to agitate the air.
It was prooved by the temperature different between the floor
and where the thermostat is. There are 6-8 degrees difference,
also room to room temperature are so different that my hands
and feet would went cold even though I set the temperature to
To prevent further damage I shut the whole system down and turned
on when the temperature dropped. By the way the whole
damage was caused by American Standard so called Comfort something
(16 ser)heat pump along with the Comfort R variable speed
furnace. Also the Air cleaner Acu clean couldn't get rid
of the oder because when I set the air flow to circulation the
air is so weak.
I have never dreamt of a air conditioning system could cause
so much damage.
So, should I tear off the entire carpet and change the baseboard
or I can just use a nail gun to nail it over the carpet?
But the floor were so uneven now, I actually felt like I stepped
on something and in some area the dark spots are visible ( I
assume those are mold, unfortunately the carpet is white)
Thank you again.
ANSWER FROM HOME-WIZARD.COM ON 4/28/2008:
Thank you for your clarification. I now have a much better idea
of what you problem is, and can do a better job of helping you
From you description, it sounds like you actually have two problems
1) how to help you fix your floor underlayment which has been
damaged by moisture, and
2) how to solve the problem that is causing the excess moisture
in your home, which has led to the damage to your floor.
Let's start with your first problem: what to do with your floor
underlayment that has been damaged? Floor underlayment is the
layer of plywood that is fastened down on top of your floor
joists. And then on top of this layer of plywood goes the surface
flooring, such as tile, hardwood, or in your case, carpet. Underlayment
is typically made of plywood, and it is glued, nailed and screwed
down to floor joists to hold it securely in place, so that it
doesn't creak. And if you have tile or hardwood flooring, it
helps keeps the tile and hardwood flooring level and from shifting
Unfortunately, it sounds like your plywood underlayment has
been exposed to excessive moisture, and as a result, it has
gotten both swollen and has been attacked by mold. At this point,
just drying the area out is probably not going to be enough.
The plywood has gotten warped, and is not likely to go back
into its correct flat shape. So where it has pulled up the nails,
it will likely stay up, and therefore you will continue to get
the squeaking noise when you walk over it (its the sound of
the nails going in and out of the wood in the floor joists as
the underlayment flexes up and down).
But more importantly, since you have already seen significant
evidence of mold formation, this plywood has become contaminated
with mold, and even if you dry it out, the mold spores can remain
in the wood, and can therefore return when the room gets humid.
This can lead to health problems in your home.
So for both of these reasons, I would suggest that you carefully
pull back the carpeting, remove the affected plywood underlayment,
and replace it with new plywood. And you should be sure to remove
all of the old glue, nails, etc. from the floor joists before
you glue, nail and screw the new plywood down. So that the new
plywood fits down tight on top of your floor joists.
Now for your other problem, regarding what is causing the excessive
moisture that ruined your underlayment? If I understand you
correctly, that you were told that you needed to add a "humidifier"
to your air conditioner system (not a "de-humidifier"), even
though you are living in the Pacific Northwest where it typically
rains half of the year, and as such the humidity is already
relatively high? And further, you have a fresh air exchanger
that is bringing outside air into your home every other 20 minutes?
A couple of thoughts here. First, it sounds like you need to
find a different HVAC contractor. I could understand possibly
adding a humidifier to run in the winter when the air might
be dry. But in the Pacific Northwest, I would not add a humidifier
unless you have measured the humidity in your home during the
winter and determined that it is indeed too low (you can purchase
a low-cost hygrometer to measure indoor humidity). But the dry
season in the PNW is so short, I would question whether a humidifier
would be a good investment.
On the other hand, it sounds like the more important issue that
you have in your home is DE-humidification. That is, how do
you get the moisture out of the air in your home.
When an air conditioner runs, it cools the air which also lowers
what's called the "dew point", that is, the temperature at which
water condenses out of the air. This is why when you look at
your air handler, you should see some tubing or piping that
allows this water that has condensed to drain out of your house
(in our Newsletter last month we had an article about how it
is important to inspect this hose at least once a year to insure
that it is draining properly).
So it sounds like your air conditioner is working hard to lower
the temperature and remove moisture from your home, but then
your installed added a humidifier that put moisture right back
The other problem is that, since you are in the Pacific Northwest,
that your fresh air exchanger is bringing up to 90% humidity
air into your home during rainy days (and of course in the PNW,
you have quite a few rainy days . . . on average 155 days per
year). So this is bringing a whole lot of moisture into your
home as well.
This is why I suggested that you find a new HVAC contractor.
It sounds like you need someone who can look at the capacity
of your current heat pump and furnace, and determine:
a) do you really need a humidifier? Can it be set so that it
does NOT run when the humidity outside is above a certain level?
b) how should your fresh air exchanger be set to operate? Can
it be set so that it does NOT run when the humidity outside
is above a certain level?
c) does your system have adequate de-humidification capacity?
I hope this is helpful Lima. If you need additional help, just
let me know.
QUESTION from paul
i have to turn my humidifier down to like 50 in order to kick
on the air, even if air is set at 65. we live in fl in a highrise
with central air. if i have thermostat on say 75 and it gets
warmer than that in the condo i have to turn humidifier to like
55 or 60 before the air kicks on. is this normal? i have not
had to move humidfier setting in the past.
ANSWER FROM HOME-WIZARD.COM on 7/13/2008
Is it a "humidifier" that you are have this problem with? Or
is it actually a "dehumidifier"?
I would assume that this time of year in Florida, that you would
be trying to reduce the humidity in your condo with a dehumidifier,
rather than trying to increase the humidity with a humidifier.
If it is indeed a dehumidifier, then the reason that it might
not be turning on is that central air conditioning acts as a
dehumidifier itself (when an air conditioner operates to reduce
the air temperature, it also reduces the dew point of the air
causing water to condense out . . . this is why air conditioners
have water dripping from them). So if the air conditioning in
your condo has already dropped the humidity down for the temperature
of the room, then this humidity level may be already below what
it takes for your dehumidifier unit to kick on.
Hope this is helpful.