Tape selection & application in humid environments
5 August, 2020
In an interior environment, it’s always best to reduce the humidity if possible. In a basement or a bathroom, for example, you may be able to use a dehumidifier to control the environment during the painting process. Not only will the tape be happier, but most prep and liquid products will work more effectively as well.
Sometimes it isn’t possible; an extreme example would be an indoor swimming pool or Jacuzzi/hot tub-type of space. You probably won’t win the battle with humidity on that scale, so that is where tape selection comes into play. 3M makes a “Masking Tape for Humid Conditions,” but with so many different types of tapes available these days, it is important for pro painters to do the research and learn which ones are designed for what use. My advice in these extreme types of indoor environments would be to pay close attention to the exact substrates that are present and try to match up tapes specifically designed for them.
For example, there is often concrete present in the “wet” types of areas I mentioned above, and there are tapes formulated for adhesion to concrete. When dehumidification isn’t possible, I try to move air with fans and introduce fresh air. Also, you will find that some tapes don’t stick well to themselves. In situations where I am unsure if the tape will hold to the substrate, I do more taping to tape, so it is important that one layer of tape can receive another lapped over it.
In exterior situations, controlling humidity is just about impossible. We don’t run into that too much here in the Northeast, but sometimes that turns into a game of picking and choosing the right times to work on exterior façades that hold humidity. You may be able to identify them by the presence of mildew or mold. As you prep those issues out, be sure to create the best possible adhesion on substrates – it’s often a good idea to sample different tapes to see which seems most compatible. Overall, you generally don’t want to use a stronger tape than necessary, so it is worth experimenting to find the one that will adhere just enough, without causing damage to surfaces (pulling finish off) or leaving a residue that can be difficult to remove.