Basement flood damage


  #1  
Old 09-21-21, 07:12 AM
A
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 240
Received 2 Votes on 2 Posts
Basement flood damage

During the Ida rainstorm I lost power. The sump pump stopped working and the basement got flooded. In the morning I noticed more than inch of water. The water finally receded but the carpet was saturated with water. I removed the carpet and disposed of it. I invited contractors to take a look. The walls were wet to the touch. Among other things, they recommended cutting off 1 foot or even 2 feet of drywall at the bottom. The last contractor arrived yesterday, some 3 weeks after the storm. He checked around with a moisture meter and indicated my walls are now dry. Also, he doesn't see any mold forming. His conclusion was that there was nothing for him to do any more. Does that sound right?
 
  #2  
Old 09-21-21, 07:36 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,117
Received 1,560 Votes on 1,403 Posts
Does that sound right?
Have you cut any exploratory holes to see inside the affected walls? The surface may indeed be dry but do you have any idea what is going on inside the wall cavity? Is there insulation that is wet? Is there a vapor barrier trapping moisture? Did any wiring get submerged?
 
  #3  
Old 09-21-21, 09:53 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 20,165
Received 1,165 Votes on 1,123 Posts
I agree with the first contractors with the idea of cutting off a foot or two of drywall. How the last guy determined there to be no mold is beyond me.
 
  #4  
Old 09-21-21, 10:16 AM
A
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 240
Received 2 Votes on 2 Posts
Pilot Dane, I did cut some portion of the drywall (see pic below). When I put my fingers inside, I didn't feel any dampness. I didn't seen any insulation but I'll admit this is not an exterior wall. No wiring got submerged.

Stickshift, the last contractor determined no mold just by sight.

By the way, is 3 grand reasonable for the job?



 
  #5  
Old 09-21-21, 10:46 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 20,165
Received 1,165 Votes on 1,123 Posts
Well, knowing you did cut away some drywall to inspect would have been nice to know from the beginning. At this point, you appear to be fine.
 
  #6  
Old 09-21-21, 11:23 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,477
Received 946 Votes on 859 Posts
That is something to consider, just because you got water in a basement doesnt always mean everything is ruined, a lot depends on what type of water.

Sewer water, yea a problem. rain water or even city water (like I had once from a leaking pipe) you might be able to get it dried out (including the carpet) with no issues.
 
  #7  
Old 09-22-21, 08:19 AM
A
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 240
Received 2 Votes on 2 Posts
Marq1, it is rain water, not sewer water.

I did cut up some sections of the exterior walls also. There doesn't seem to be any insulation. I can directly see the cinder blocks. When I run my fingers on the inside of the drywall, I don't feel any dampness.

Parts of the basement are wallpapered. I noticed that some of it is peeling away. I lifted the flaps and noticed some black spots on the underside of the wallpaper and the drywall it's in contact with (see pics below). Is this mold? I sprayed some Concrobium mold control solution on these spots and let it sit overnight. The black spots remain. What should be my next step? Should I fog the entire basement for mold control?



 
  #8  
Old 09-22-21, 10:48 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,477
Received 946 Votes on 859 Posts
Have you checked the moisture level?

Knowing what that is and a means to lower it (dehumidifier) is a critical step.

Mold can not grow in a dry environment!
 
  #9  
Old 09-22-21, 11:03 AM
A
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 240
Received 2 Votes on 2 Posts
Marq1, I have a dehumidifier, 4 fans and basement lights on 24x7 from the very beginning. The dehumidifier was showing a reading in the 80s right after the flood. These days (3 weeks later) it is showing a reading in the 40s. Let me also mention this strange behavior. During the day, I see the humidity level (as shown on the dehumidifier) declining from a level of 50 to about 40 at which point the water full signal lights up. At that point, I empty the water bucket. Upon re-inserting the bucket, the dehumidifier reading again jumps to 50, and over a period of hours, keeps declining till water bucket is full and the cycle repeats. However, in a week to week comparison, the max reading has been steadily lowering.
 
  #10  
Old 09-23-21, 05:54 AM
A
Member
Join Date: Mar 2010
Location: USA
Posts: 4,928
Received 214 Votes on 197 Posts
If the dehumidifier is kicked on (specifically not shut off due to a full bucket), if you record the humidity reading, empty the bucket, and put the bucket back all within three minutes, then an hour later the humidity should read about the same as when you emptied the bucket.

Otherwise the meter on your dehumidifier might be measuring something else, say, the level of water in the bucket.
 
  #11  
Old 09-23-21, 07:33 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,477
Received 946 Votes on 859 Posts
I would bet the meter on the dehumidifier is more for reference, an inexpensive hygrometer might be needed.

Get that relative humidity down to 35% for extended period of time and you will kill off any mold present.
 
  #12  
Old 09-23-21, 08:24 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,117
Received 1,560 Votes on 1,403 Posts
Keep in mind that killing mold and an environment where it can grow are two separate things. Low humidity will not kill mold. The spores will simply go dormant and wait for humidity to rise again. If you want to kill the mold removal is certainly a effective method which is why the submerged sheetrock and carpeting is usually removed. There are also chemical treatments that can kill mold spores but the problem is with porous and fragile surfaces like sheetrock is applying enough to penetrate deep and kill the mold without damaging the sheetrock.

If you have a musty or damp odor you can also consider ozone treatment. You need high concentrations but it can be very effective at breaking down odors and kill mold and it's spores. And, because ozone is a gas it is great at penetrating into porous surfaces and nooks & crannies. Unfortunately when most people do DIY ozone treatments they don't use anywhere near the required concentration. You would need properly sized ozone generator(s), turn off the HVAC system and seal the basement for treatment. It is possible that enough ozone will leak out of the basement to make the house uninhabitable or uncomfortable while treatment is in progress. When treatment is done a few hours airing out the house will get rid of it.
 
  #13  
Old 09-23-21, 11:25 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,477
Received 946 Votes on 859 Posts
I typed that wrong, the statements should have been

Get that relative humidity down to 35% for extended period of time and you will prevent the occurrence of mold.

 
  #14  
Old 09-23-21, 12:06 PM
A
Member
Thread Starter
Join Date: Aug 2009
Location: USA
Posts: 240
Received 2 Votes on 2 Posts
AllanJ and Marq1, according to the product's user manual, the dehumidifier displays the humidity level or an error code. When the bucket is full, it displays the corresponding error code and not the humidity level. Before the bucket is full, I've seen it go as low as 39. AllanJ, I'll try the experiment you suggested.

Pilot Dane, you're making a good point about killing mold and an environment where it can grow being two separate things. I've already removed the wet carpet. The drywall is no longer wet. The humidity level is now low though not down to 35 yet. I feel that the environment does not encourage further mold growth. However, I happened to peel off the wallpaper at another place and found more black spots, see pic. It's hard to tell whether this is due to the recent flood or a pre-existing condition that went unnoticed. The water level was only an inch and it could not have gone all the way up to where the black spots are located. I've decided to get rid of all the wallpaper. What do you think of fogging the area with Concrobium mold control? The fog will penetrate porous surfaces like drywall. I can't tell anymore if there's a musty odor because now my nose is used to whatever odor that previously existed. I'll ask a friend to render their opinion.


 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: