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Best strategy basement mold

Posted: Sun Nov 04, 2018 8:01 pm
by PoultryMan
I am about to remove my basement carpet and install floating vinyl flooring. As I look closely there is some slight mold on the bottom inch or two of my leather sofas and coffee tables.

I am cleaning the furniture with a 50/50 mix of water and apple vinegar, which seems to be working, I needed to soak and wipe twice, but there is progress. I just ordered concrobium to spray on the baseboards and am about to re paint the room and use mold killing primer on the walls. I think I am also able to roll the primer on the slab floor. I think some of the mold is in the carpet. I was hoping the installers could remove the carpeting and I am paying them to do so but don’t want to take the chance of there being mold under the new flooring.

Years ago one wall of about 8 feet of drywall got wet from a heavy flood, but other than that the walls should be ok, I guess.

Also curious if anyone has used an ozone machine?

Am I overly worried about this? Is there a better way to remediate it? The only visible mold I see is on the bottom of the furniture

Re: Best strategy basement mold

Posted: Sun Nov 04, 2018 9:09 pm
by shunkman
We have a below-grade family room. We run a ceiling fan 24/7 and a dehumidifier set at 50%. Mildew is no longer a problem for us.

Re: Best strategy basement mold

Posted: Mon Nov 05, 2018 3:31 am
by Rexindex
I second the dehumidifier idea.

As for ozone, I don’t know I feel it kills mold.

Re: Best strategy basement mold

Posted: Mon Nov 05, 2018 7:36 am
by markcoop
I live in the Northeast. Winters tend to be dry. Curious if people run dehumidifiers in the basement in the winter?

Re: Best strategy basement mold

Posted: Mon Nov 05, 2018 8:21 am
by Rus In Urbe
We had a mold problem because we have a 1925 house with a basement with concrete walls that would occasionally weep. Parging bubbled and there was some moisture on the floor after rains. Given the way the climate is changing, with more rain-bombs in the future, I was planning for extremes.

I had the entire basement wrapped in double thick plastic sheeting and a French drain installed below the concrete floor so that any moisture would run into a sump pump and be expelled onto the front lawn. You can find this online, called the BDry system. Works great. I did not want to see any more moisture ever. Like you, we run a dehumidifier anyway. This wrapping system is expensive and may be more than you need, however.

When we had the project done, I had the workers wash the floor twice with bleach before installing a floating vinyl floor. I admit to going a little extreme, but the mold problem had been around probably since the house was built. Like you, I did not want to take the risk of mold re-appearing. It was all a nasty job, but the results were terrific.

Five years later----no problems ever, even during heavy rainstorms and no mold anywhere. I couldn't be happier with the project, as it added a very usable floor to the house.

Re: Best strategy basement mold

Posted: Mon Nov 05, 2018 11:38 am
by forgeblast
We use de- humidifiers in our basement and just used rhino tuff cleaner and mold preventive. Seems to be working great.
Before you put the floating floor down. I remember being told to do a test. Take plastic and duct tape it to the floor for a day or two to see how much moisture is in there. IF there is too much you need a different underlayment.

Re: Best strategy basement mold

Posted: Mon Nov 05, 2018 11:46 am
by HereToLearn
markcoop wrote:
Mon Nov 05, 2018 7:36 am
I live in the Northeast. Winters tend to be dry. Curious if people run dehumidifiers in the basement in the winter?
I live in the NE and run the dehumidifier when the temperature goes above 60. I have no idea why that is my breakpoint, so I would seek advice from someone who has a better explanation. We do not get water in the basement when it rains (no sump pump, French drain, etc), but when a section of the roof was off during construction, water came in and sat on the concrete floor. The particleboard shelves that were above that water (never touching the ground) must have absorbed the water, and mold grew on the underside. I have run a dehumidifier since. I am amazed at how much water it pulls out of the air every day.

The finished section of the basement is completely above ground, and no mold 20 years later.

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 5:47 am
by nativenewenglander
HereToLearn wrote:
Mon Nov 05, 2018 11:46 am
markcoop wrote:
Mon Nov 05, 2018 7:36 am
I live in the Northeast. Winters tend to be dry. Curious if people run dehumidifiers in the basement in the winter?
I live in the NE and run the dehumidifier when the temperature goes above 60. I have no idea why that is my breakpoint, so I would seek advice from someone who has a better explanation. We do not get water in the basement when it rains (no sump pump, French drain, etc), but when a section of the roof was off during construction, water came in and sat on the concrete floor. The particleboard shelves that were above that water (never touching the ground) must have absorbed the water, and mold grew on the underside. I have run a dehumidifier since. I am amazed at how much water it pulls out of the air every day.

The finished section of the basement is completely above ground, and no mold 20 years later.
I live in northern NE when we bought 150 year old house I had the basement foamed with 1 inch of closed cell urethane.It keeps the basement warm and there are no more seeps of water coming in or mice for that matter. We run a dehumidifier we empty every few days in warm weather but now that it's getting cool it's once a week by Christmas I won't have to empty it at all. It's kept at 50% relative humidity.

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 5:54 am
by unclescrooge
Based on advice I received in a recent thread, I bought a frigidaire 50 pint dehumidifier for my finished, 700 sq ft walk-out basement in SoCal.

That has solved the humidity issues, however it runs continuously and is pretty noisy. The fact that I have tile floors and bare walls doesn't seem to help.

How do you deal with the noise issue?

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 9:43 am
by 3feetpete
I used a dehumidifer to keep my basement mold and mildew free. It had a built in humidistat so it only ran when necessary and generally not at all in the winter. The reason mold is common in basements is that in the summer the basement is usually cooler than outside. So air that infiltrates from outside gets cooled down and the relative humidity increases.

I recommend you get a humidifier that allows you to gravity drain into a sink or other drain. I set mine on a wall and drained it into a laundry sink. You don't want to be emptying a tank every day. Friedrich also makes models that have a built in pump so they can be set on the floor and the condensate is pumped up to a drain.

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 10:16 am
by sjt
unclescrooge wrote:
Tue Nov 06, 2018 5:54 am
however it runs continuously and is pretty noisy.
How do you deal with the noise issue?
Have you checked the humidity level? If it's running continuously, it may be overwhelmed. I put a 90 pint / 2600 sqft dehumidifier (brand is Alorair) in the crawlspace and it's very quiet even when I'm in the crawlspace. Maybe when your current one gives up - look at a more heavy duty model?

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 11:39 am
by GrowthSeeker
PoultryMan wrote:
Sun Nov 04, 2018 8:01 pm
I am about to remove my basement carpet and install floating vinyl flooring. As I look closely there is some slight mold on the bottom inch or two of my leather sofas and coffee tables.

I am cleaning the furniture with a 50/50 mix of water and apple vinegar, which seems to be working, I needed to soak and wipe twice, but there is progress. I just ordered concrobium to spray on the baseboards and am about to re paint the room and use mold killing primer on the walls. I think I am also able to roll the primer on the slab floor. I think some of the mold is in the carpet. I was hoping the installers could remove the carpeting and I am paying them to do so but don’t want to take the chance of there being mold under the new flooring.

Years ago one wall of about 8 feet of drywall got wet from a heavy flood, but other than that the walls should be ok, I guess.

Also curious if anyone has used an ozone machine?

Am I overly worried about this? Is there a better way to remediate it? The only visible mold I see is on the bottom of the furniture
Unfortunately, I had some experience with this problem. The professionals use quaternary ammonium cleaning products for mold; for example this one
https://www.amazon.com/Mediclean-Disinf ... roban&th=1
The quaternary ammonium liquid can also be aerosol-ized by a fogging machine (but you need a monkey suit and full face mask to do that).

I looked up Concrobium and its active ingredient is: Sodium Carbonate.
Does this make a huge difference? Probably not.
If you clean off the surface mold and then decrease the humidity below a certain point, you should be fine.

The exception is, if you have mold where you can't see, like behind drywall. The best indicator of this (short of tearing it out and looking) is someone with a sensitive sense of smell who can smell mold. Some people are amazingly poor at smelling mold, perhaps because they are around low levels of mold a lot.

Drywall has paper on both sides: once it gets wet, the chances it has mold on both sides is high. If the humidity is low enough, the mold is dormant; when the humidity is high enough, the mold grows

Another very helpful tool is a Humidity Monitor such as this one:
https://www.amazon.com/AcuRite-Humidity ... dity+gauge
Particularly if you take a measurement before you start dehumidifying.

The most convenient way to dehumidify is to get a short hose attached to the back of the dehumidifier, such that it drains by gravity into a floor drain, a washtub drain, a sump pit. Most of these will not pump uphill, so it will have to drain by gravity (those with a pump function exist, but more expensive).

Speaking of drains: if you have any drains in the basement that you essentially never use, put some water down them every so often so that the trap won't dry out and allow in sewer gases.

Ozone will oxidize molecules that cause smell including mVOCs (mold Volatile Organic Compounds), and I think this happens at fairly low ozone levels. I can't prove it, but just from general science knowledge I believe that it probably takes much higher levels and longer contact times for ozone to kill mold cells and mold spores. There are also health side effects from high ozone levels (to pets and humans) which you don't want. How high a level to kill mold spores vs how high for health hazards? I don't know. But you could run toxic levels of ozone for a week, kill lots of mold; but if it is still humid, it will just be a temporary benefit.

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 12:38 pm
by rgarling
PoultryMan wrote:
Sun Nov 04, 2018 8:01 pm
...
Also curious if anyone has used an ozone machine?
...
High concentrations of ozone can kill mold and mildew; however, you don't want to be in there when the machine is being used. Before re-entering make sure the ozone has completely dissipated.

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 3:47 pm
by unclescrooge
3feetpete wrote:
Tue Nov 06, 2018 9:43 am
I used a dehumidifer to keep my basement mold and mildew free. It had a built in humidistat so it only ran when necessary and generally not at all in the winter. The reason mold is common in basements is that in the summer the basement is usually cooler than outside. So air that infiltrates from outside gets cooled down and the relative humidity increases.

I recommend you get a humidifier that allows you to gravity drain into a sink or other drain. I set mine on a wall and drained it into a laundry sink. You don't want to be emptying a tank every day. Friedrich also makes models that have a built in pump so they can be set on the floor and the condensate is pumped up to a drain.
Which model dehumidifier did you get?

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 7:35 pm
by randybobandy
markcoop wrote:
Mon Nov 05, 2018 7:36 am
I live in the Northeast. Winters tend to be dry. Curious if people run dehumidifiers in the basement in the winter?
I turn off the dehumidifier when I start getting shocked.

Re: Best strategy basement mold

Posted: Tue Nov 06, 2018 8:10 pm
by ralph124cf
I would like to suggest ceramic or porcelain tile set in mortar instead of vinyl. Mortar gets harder with moisture, vinyl adhesive fails with excessive moisture. If you have a minor flood, the floor will not be harmed if set in mortar.

Ralph

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 10:33 am
by Doug E. Dee
markcoop wrote:
Mon Nov 05, 2018 7:36 am
I live in the Northeast. Winters tend to be dry. Curious if people run dehumidifiers in the basement in the winter?
No, I unplug it once the humidity level drops to the point where the dehumidifier is no longer coming on. Unplugging also protects it from any wintertime power hits.

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 11:48 am
by nativenewenglander
unclescrooge wrote:
Tue Nov 06, 2018 3:47 pm
3feetpete wrote:
Tue Nov 06, 2018 9:43 am
I used a dehumidifer to keep my basement mold and mildew free. It had a built in humidistat so it only ran when necessary and generally not at all in the winter. The reason mold is common in basements is that in the summer the basement is usually cooler than outside. So air that infiltrates from outside gets cooled down and the relative humidity increases.

I recommend you get a humidifier that allows you to gravity drain into a sink or other drain. I set mine on a wall and drained it into a laundry sink. You don't want to be emptying a tank every day. Friedrich also makes models that have a built in pump so they can be set on the floor and the condensate is pumped up to a drain.
Which model dehumidifier did you get?
I have this model Frigidaire, it's the best unit I have owned over the last 25 years. Quiet and reliable. There are ways to have the water gravity feed into a bucket then pump it out to your drain field. Youtube is your friend here. https://www.amazon.com/Frigidaire-50-Pi ... 1340&psc=1

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 11:54 am
by 3feetpete
unclescrooge wrote:
Tue Nov 06, 2018 3:47 pm
3feetpete wrote:
Tue Nov 06, 2018 9:43 am
I used a dehumidifer to keep my basement mold and mildew free. It had a built in humidistat so it only ran when necessary and generally not at all in the winter. The reason mold is common in basements is that in the summer the basement is usually cooler than outside. So air that infiltrates from outside gets cooled down and the relative humidity increases.

I recommend you get a humidifier that allows you to gravity drain into a sink or other drain. I set mine on a wall and drained it into a laundry sink. You don't want to be emptying a tank every day. Friedrich also makes models that have a built in pump so they can be set on the floor and the condensate is pumped up to a drain.
Which model dehumidifier did you get?
I bought the Friedrich 50 pint model with gravity drain. I don't own a house with a basement anymore but I also bought one for my beach vacation condo and set it on the kitchen counter when I'm away and drain into the sink. It runs a lot in the summer and has given me years of service. The condo used to smell of mildew in the summer but not since I started using the dehumidifier. I don't know if it runs at all in the winter but I just keep it plugged in and set at 50% humidity.

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 12:20 pm
by unclescrooge
nativenewenglander wrote:
Wed Nov 07, 2018 11:48 am
unclescrooge wrote:
Tue Nov 06, 2018 3:47 pm
3feetpete wrote:
Tue Nov 06, 2018 9:43 am
I used a dehumidifer to keep my basement mold and mildew free. It had a built in humidistat so it only ran when necessary and generally not at all in the winter. The reason mold is common in basements is that in the summer the basement is usually cooler than outside. So air that infiltrates from outside gets cooled down and the relative humidity increases.

I recommend you get a humidifier that allows you to gravity drain into a sink or other drain. I set mine on a wall and drained it into a laundry sink. You don't want to be emptying a tank every day. Friedrich also makes models that have a built in pump so they can be set on the floor and the condensate is pumped up to a drain.
Which model dehumidifier did you get?
I have this model Frigidaire, it's the best unit I have owned over the last 25 years. Quiet and reliable. There are ways to have the water gravity feed into a bucket then pump it out to your drain field. Youtube is your friend here. https://www.amazon.com/Frigidaire-50-Pi ... 1340&psc=1
I bought that exact model couple of weeks ago and it's running it in the shower for now. Yes, now I wish I had bought a gravity drain version.

It only emits 55 decibels, but the acoustics of the rooms make it sound much, much louder.

Once I install the kitchen, I'll drain it to the sink. Hopefully a thick rug and more furniture will help with the sound.

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 12:20 pm
by unclescrooge
3feetpete wrote:
Wed Nov 07, 2018 11:54 am
unclescrooge wrote:
Tue Nov 06, 2018 3:47 pm
3feetpete wrote:
Tue Nov 06, 2018 9:43 am
I used a dehumidifer to keep my basement mold and mildew free. It had a built in humidistat so it only ran when necessary and generally not at all in the winter. The reason mold is common in basements is that in the summer the basement is usually cooler than outside. So air that infiltrates from outside gets cooled down and the relative humidity increases.

I recommend you get a humidifier that allows you to gravity drain into a sink or other drain. I set mine on a wall and drained it into a laundry sink. You don't want to be emptying a tank every day. Friedrich also makes models that have a built in pump so they can be set on the floor and the condensate is pumped up to a drain.
Which model dehumidifier did you get?
I bought the Friedrich 50 pint model with gravity drain. I don't own a house with a basement anymore but I also bought one for my beach vacation condo and set it on the kitchen counter when I'm away and drain into the sink. It runs a lot in the summer and has given me years of service. The condo used to smell of mildew in the summer but not since I started using the dehumidifier. I don't know if it runs at all in the winter but I just keep it plugged in and set at 50% humidity.
Doesn't it take up a lot of space? How large is your condo?

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 6:11 pm
by ByThePond
I second the use of quaternary ammonium compounds like benzylkonium chloride as a mold/mildewcide. It's a very effective, all-purpose sanitizer that's widely used in food processing equipment, water systems and swimming pools . That as a cleaning agent and a dehumidifier should handle most situations.

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 8:13 pm
by 3feetpete
unclescrooge wrote:
Wed Nov 07, 2018 12:20 pm
3feetpete wrote:
Wed Nov 07, 2018 11:54 am
unclescrooge wrote:
Tue Nov 06, 2018 3:47 pm
3feetpete wrote:
Tue Nov 06, 2018 9:43 am
I used a dehumidifer to keep my basement mold and mildew free. It had a built in humidistat so it only ran when necessary and generally not at all in the winter. The reason mold is common in basements is that in the summer the basement is usually cooler than outside. So air that infiltrates from outside gets cooled down and the relative humidity increases.

I recommend you get a humidifier that allows you to gravity drain into a sink or other drain. I set mine on a wall and drained it into a laundry sink. You don't want to be emptying a tank every day. Friedrich also makes models that have a built in pump so they can be set on the floor and the condensate is pumped up to a drain.
Which model dehumidifier did you get?
I bought the Friedrich 50 pint model with gravity drain. I don't own a house with a basement anymore but I also bought one for my beach vacation condo and set it on the kitchen counter when I'm away and drain into the sink. It runs a lot in the summer and has given me years of service. The condo used to smell of mildew in the summer but not since I started using the dehumidifier. I don't know if it runs at all in the winter but I just keep it plugged in and set at 50% humidity.
Doesn't it take up a lot of space? How large is your condo?
It's not very large. A little larger than a typical office wastepaper basket.
From their website. Dimensions (WxHxD) 15” x 23 1/4” x 12”
When I'm using the condo I take it off the counter and store it in a closet.

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 9:29 pm
by PoultryMan
I have A small wet bar. Other than that I have no way of having a dehumidifier drain if running constantly. I have limited space to place a small one above the sink.

What are my options? I don’t see myself running downstairs every few hours to drain a self contained dehumidifier

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 10:40 pm
by longleaf
If the unit has a pump, you can run a hose into the sink and place the unit elsewhere.

Re: Best strategy basement mold

Posted: Wed Nov 07, 2018 10:45 pm
by whodidntante
Mold = moisture, specifically > 50% relative humidity in a wood framed house. Check to make sure your air conditioner condensate drain is not clogged. I clean mine once a year, or at least every second year.

Re: Best strategy basement mold

Posted: Thu Nov 08, 2018 8:53 am
by gd
GrowthSeeker wrote:
Tue Nov 06, 2018 11:39 am
I looked up Concrobium and its active ingredient is: Sodium Carbonate.
Web site says Tri sodium Phosphate, FWIW.

My experience is that humidity in NE basements will depend largely on your individual circumstances-- foundation depth, insulation, sealing and local water table, basement heating and ventilation. In summers I seal it up or get puddles of water from humid air on cool floor and walls, in winters I'm better ventilating.

Re: Best strategy basement mold

Posted: Thu Nov 08, 2018 10:28 am
by GrowthSeeker
gd wrote:
Thu Nov 08, 2018 8:53 am
GrowthSeeker wrote:
Tue Nov 06, 2018 11:39 am
I looked up Concrobium and its active ingredient is: Sodium Carbonate.
Web site says Tri sodium Phosphate, FWIW.

My experience is that humidity in NE basements will depend largely on your individual circumstances-- foundation depth, insulation, sealing and local water table, basement heating and ventilation. In summers I seal it up or get puddles of water from humid air on cool floor and walls, in winters I'm better ventilating.
It's a candy mint. It's a breath mint. Stop! You're both right.

The safety data sheet (updated 2015) lists both compounds, the TSP quantity is between 1 and 5 % by weight, and the Sodium Carbonate is less than 1%. The latter is the sodium salt of carbonic acid. The SDS lists the pH of the product at about 11.3