It is difficult to give you proper advise when I cannot see the property in person, so everything I state here will be based on assumptions.
I think it is important that you remove all infected materials. I am in the environmental services business and highly recommend you seek professional help to do the remediation. The average home owner does not have the proper equipment nor training to perform such a task. However, if you cannot afford it, you may want to handle the removal of the material and hire someone to sanitize the basement.
You may want to test to see what type of mold it is. In my opinion it is always best to know what you are dealing with to get a full picture of the problems.
I could be wrong, but the basement does not seem like it has significant water problems.
Your problems seem to be fairly typical when it comes to mold and finished basements. Most basements are not conducive to healthy living areas. Any amount of water in a finished basement can turn to mold issues.
Removing the infected material and killing the mold in your basement are the first steps. Once you disturb the areas with mold, mold spores will be released into the air. These spore will just loft around waiting for a suitable place to colonized. The will not die unless you kill them. HEPA Air filtration is a must.
You do not want any cross contamination, so the upstairs must be sealed off from the basement during the working process.
It is important to kill the mold and mold spores on all surfaces in the air.
Failure will just result in further mold growth over time.
Anyone working around mold must take proper precautions and protect themselves from mold exposure by wearing Personal Protective Equipment. Wearing a full face respirator with proper cartridges for mold is essential.
Once you have the basement cleaned out and the mold addressed, live with the basement to watch for water intrusion. Over time you will be able to properly assess the situation.
If your walls are painted, the Sani-Tred product will not function properly nor will Sani-Tred recommend it's use.
I hope this information helps. Again, try to go the professional route first. Call a few mold experts in your area for quotes. I will look at the quotes for you and help any way I can.
Newly renovated cottage has a problem with mold on the basement walls, and ceiling. There is no water leaking into the basement or coming up through the floors but there is a lot of humidity coming up through. The floors are dry, and so are the walls, and ceiling to touch. Inside and outside weeping tiles were installed with tarred outside wall but no plastic underneath the cement floor, and the cement is only about 2-3 inches thick. Would Sani-Tred fix this problem before I put sub floors down? Also could this problem be caused from another source. Advice or suggestions would be great.