Mold Remediation in the Crawl Space of a Fifty Year Old House
Here is our experience with mold remediation.
We owned a house a few years ago which we were trying to sale. The prospective buyer had a home inspector come in and do some testing.
The inspector determined that the house had black mold in the crawl space. He suggested to the buyer that they have the seller remediate the mold before they bought the house.
I being the seller was given a copy of the test report. So, I then called the testing lab and starting asking questions. They would not provide any answers as I was not the person that paid for the report. The buyer was paying for it. (I was just trying to determine exactly what was in the report. My knowledge of latin is zilch).
Then I called the inspector and all he wanted was exactly how I had gotten a copy of the report. That raised a red flag for me.
Remediation Company Call No. 1: This mold remediation company recommended, over the phone, a repair bid to rid the home of mold in the crawl space of $22,000.00. That company wanted to replace all the floor joists.
NOTE: there was no material damage. There were just mold spores growing on the floor joist one inch below the fiberglass insulation. There was no mention of them installing plastic ground cover.
Houses built today have a plastic vapor barrier in the crawl space on the ground. This is a reduce ground moisture in the crawl space. Houses built 50 years ago didnt require this.
Also, the mold remediation company used the inspectors report and never even looked under the house.
Remediation Company Call No. 2:That company wanted to place a thick membrane in the crawl space and seal everything up to the bottom of the floor joist.
Then they wanted to add power fans to reduce the moisture. They were just going to clean the mold spores off the existing floor joist, not replace them. The estimate from them was a little over $5,000.00.
The fans made no sense to me as this would have brought MORE moisture into the crawl space. The living space had air conditioning and as the air conditioning seeped through the floor, it would have cooled the moisture in the crawl space resulting in more mold.
Remediation Company Call No. 3: They wanted to close the foundation vents, place plastic on the ground and spray an EPA approved chemical on the joist to stop the growth of the mold.
By the way, it was just common mold and not black mold. The final cost was just over $1,200. This is the company we went with to fix the problem
A month later I saw a video at my local real estate investors club about fans to vent the crawl space. It showed a house built in the 1940s with no vents and just an access door. There was straw on a dirt floor and it was in good condition. There was no mold of any kind.
The video showed another house that had been built several years ago several hundred feet away from the first house and this one had foundation vents. There was mold. To fix the mold problem, the owner installed power ventilators (fans). Six months later the mold had gone wild. The fans were removed and the foundation vents sealed. Six months after that the mold was gone.
So, the question really is should you vent the foundation or not? The answer for my situation was not to vent! Also, if you are told you have black mold, be sure to get a second opinion before you spend money for mold remediation.