Major differences between interior and exterior paint
The proportions of each component as well as their types make the difference between interior and exterior paint. Exterior paint, for example, might feature more resins and special additives to increase resilience. However, these additional components might cause outgassing, releasing VOCs, or Volatile Organic Compounds.
Depending on factors like ventilation efficiency and house insulation, even interior paint might take a couple of months before the paint fully cures and all VOCs are removed. This is why paint with high VOC count is usually used in exterior painting, as the gasses can safely dissipate into the air (which, depending on the paint used, might also not be the best for the environment).
Specifics of exterior and interior painting
Exterior paint can slowly release VOCs for up to several years after painting, with additional substances that prevent mould and mildew growth, as well as weatherproofing the outside of a building.
Interior painting, on the other hand, doesn’t require paint that is as durable and weatherproof as the one used on the exterior. These paints feature low VOC count, and some brands even offer VOC-free alternatives. Most interior paints still feature additives to make them scratch and stain resistant and come in a range of finishes, from matte to gloss.
Preparing for a renovation project? Take a look at our preparation guide for interior painting as well as our exterior painting in London guides for Spring, Summer, and Autumn. You’ll find more helpful painting and decorating tips at our blog.