Mold is generally thought of as a bad thing. Much of the time it is, but is also normal to have mold in varying degrees, and to avoid it completely is pretty difficult.
Mold can cause a lot of ailments. Some forms of mold are harmless, but some are toxic, and some merely irritating if you happen to be sensitive to it. Respiratory ailments especially can be caused or exacerbated by the presence of mold and mold spores, which is the equivalent to its seeds or eggs. These spores in themselves can be toxic to humans and animals if inhaled or absorbed in high enough concentrations. I had two dogs that became quite ill an developed severe skin rashes and infections when exposed to mold. We ourselves were generally sneezing, tired, grumpy and congested, and eventually came tpo the conclusion that all of these symptoms were attributable to the presence of mold.
Not really understanding what was going on, we suffered for years until be purchased our first new house. Since it was new construction mold had not yet developed to an extent that we had previously experienced in a 30 year old home-with moisture issues, and our allergies and other ailments disappeared shortly after the move.
Mold needs moisture and some sort of food to grow. Wood, linoleum, and vinyl can be food for it.
A dry, arid environment is most hostile to mold growth. Unfortunately it’s not always easy to maintain such an environment in your home, even if you live in an arid region. We bring in food, drink, and ourselves into it, and most of us use water to clean things, like laundry, surfaces, and of course, our selves. This is why mold in the bathroom is generally the rule and not the exception.
How does moisture get in?
One way is moisture intrusion through the foundation…
Many people think that concrete is waterproof. After all it is used in pools, sidewalks, foundations and roads, and even under your bathroom shower. Well guess what, concrete is porous. Not only isn’t it waterproof, it actually can conduct moisture from the outside world into your home. This is why there is a moisture barrier installed under most slab foundations, often in the form of clear plastic sheeting.
Sometimes it works, and sometimes it doesn’t…
There are various grades and types of concrete used in foundations. Some are more likely to promote moisture intrusion than others. The cost differential is not extreme, at least for the material, but the better concrete takes longer to cure which may delay construction time. On a large project this can be very costly to a builder, so there are times when the builder will take a shortcut. It doesn;’t always cause problems. The type of concrete used is dependent upon the soil and moisture conditions present, along with other factors. However, there have been serious problems that have resulted in soem very sick people and very serious damage that also resulted in tens of millions of dollars in settlements at the expense of major builders because they took these shortcuts in the wrong place at the wrong time.
How do I know all this? Uh, I learned about it the hard way. I purchased a home that was involved in one of these suits, after deciding it was worth the risk. We had been looking for months, and decided that the situation was manageble, especially if we won the suit. Actually had we known all the facts when we made the offer we may have passed on it, but we sure learned a lot as we went through the process.
We ending up making significant modifications to the home, all aimed at keeping moisture out of the house in critical areas. For starters, we replaced the sprinklers that were shooting water up against the wall of the house with ones pointing the other direction. Pretty simple, and pretty effective.
This was in southern California, and irrigating the lawn was an almost daily occurrence. The exterior was stucco, which is essentially a layer of colored concrete. While it is fine to get it wet, the constant bombardment inevitably lead to some moisture intrusion, and imperfections or holes in the surface can exacerbate this. Also, the water obviously enters the soil and can be absorbed into the foundation, which in our case would then wick the moisture through the foundation causing problems with the vinyl flooring, carpets, and under the cabinetry. There was a moisture barrier which apparently was not getting the job done.
I am not sure why or how, but somehow water was being absorbed by the concrete and transmitted through the foundation into the home. The flooring in the laundry room had to be replaced twice in 5 years, and had a severe mold problem. There was also mold under the kitchen cabinets, and probably elsewhere.
Sealing the foundation.
A foundation can be sealed with on the top surface or on the bottom. Obviously it’s better done from the bottom, but this is hardly practical after the home is built, especially on a slab foundation that contains the pipes. There is a process that involves boring holes in the foundation and injecting waterproof material to seal it form the bottom, but because of the number of holes required the remaining foundation resembles Swiss cheese and it is near impossible to guarantee that the surface is properly protected. Not to mention that this is really, really expensive. Also some slab foundations have cables running through them that strengthen them, and this feature is disturbed by the process.
Sealing the inner surface is much easier and far more cost effective. Still, it’s not cheap and probably is only appropriate if you have identified a problem. You may have observed a similar process applied to sores with exposed concrete floors. The concrete surface is thoroughly cleaned and textured. Basically either sanded or in our case treated with what amounts to sand blasting the surface. The surface is bombarded with small iron balls, sort of like ball bearings or bee bees, which removes a layer of concrete making it an excellent surface to apply the sealant or sealants to. This is very helpful in achieving a stable long term bond. The surface was guaranteed for minimum of 10 years, and projected to last much longer.
Of course, all of the flooring has to be removed and replaced. We elected to not replace the few areas that had tile, as the process of securing tile to concrete seals it pretty well anyway. We did take out ALL the linoleum floors and carpeting. The entire slab was treated and sealed, with an extra layer of sealant installed under the new tile. It turns out that the material used for the initial layer is not something that tile adhesive sticks to, so an additional layer is required before laying tile.
Under the kitchen cabinets was another story. We got estimates for removing and replace the cabinets, and the cost was hard to accept. We removed the toe kicks (the3” of wood at the base of the cabinets) and found mold, but not to the extent that the rest of the cabinets were not salvageable. The house was only about six years old, so anything not directly in contact with mold was not severely damaged.
We elected to seal the concrete under the cabinets after cleaning and sanding and treating and letting the surface dry for several weeks. We couldn’t get a contractor to do it, so we did it ourselves with the best coating we could find. We didn’t want to have to open it up again and it was a relatively small area, so we did not go cheap here. Replacing the toe kicks was far less expensive than replacing the entire cabinet array, especially since we were having other work done that involved similar wood and the craftsman was a friend.
So does any of this sound like fun? In another environment we might have delayed the purchase until we found a non-affected home, but at that point home prices were escalating rapidly and we were under time constraints. The actions we took appear to have been successful, and we noticed no further moisture damage.
You may not have to go to these lengths to protect your home, but if you find mold or moisture be sure to have it checked out by a pro. Mold is usually not a death sentence, but it is definitely to be taken seriously. We did nto go into this without the advice, both official and unofficial, of several experts in different fields. It would have been very easy to over-or under-react, but looking back we feel like we followed the right course.
My advice? Do reaserch, get information, and listen to both your head and your heart. I hope I’ve given you some good information to help you get to where you need to go.