What Causes Exterior Blistering When House Painting in San Ramon?

When house painting in San Ramon, the one thing nobody wants to see when the job is done is blistering in the exterior paint. In order to avoid having these appear, you will need to know what causes them. There are also ways to fix them if they show up anyway.

Blistering is what happens when the top layer of paint is separated from the layer underneath by air or water. Sometimes the possibility of blistering is apparent, while at other times it sneaks up on you. Either way, there are ways to avoid them so that it is less likely to happen.

Moisture is a big reason for blistering in exterior paint. If it has been raining or if the area was washed but not dried thoroughly, or if there is a leak, then moisture is in the area. Being careful to make sure that the entire area is dry and there are no leaks is one way to prevent moisture from causing blistering. This is obviously more important in humid areas, since there is more ambient moisture in those conditions. Choosing to paint an exterior surface on a dry, sunny day is the best option.

Mixing types of paint can also cause blistering. Because latex and oil paints do not respond the same way to heat, one will expand more quickly than the other and blistering will occur. There are primers that can be layered between paint types to help them bond more effectively. However, it is usually best to just paint the new coat with the same type of paint as was used previously.

Painting a new coat before the previous one is dry can also cause blistering. Because you are cutting off lower layers from the factors that speed drying, the upper layer is likely to dry first, leaving a layer that may still be releasing solvent vapors. These will blister, or bubble, because the upper layer will not allow it to be released into the air.

Additionally, if the area is not clean enough, residual dirt can cause blistering. Paint that is spread over dirty surfaces will not stick properly, and will pull away from the surface.

If you have done all you can to prevent blistering, but still find yourself faced with blisters in your exterior paint, the best way to handle it is to scrape the affected paint off, smooth it with sandpaper, dry it completely, and repaint. If the same area blisters again, check for leaks or other moisture traps in the wall behind it.

It is not always possible to prevent blistering when house painting in San Ramon, but if you know what to look for, you have a much better chance of avoiding them.