Hardboard is a fiberboard or wood composite material used in woodworking or building projects. Hardboard is used primarily in houses, but it is sometimes used for painting canvas frames or other artistic materials and any other woodworking project that requires stronger materials. According to Design Technology, hardboard has a few available options such as standard, oil tempered and medium hardboard, which make it very versatile, but it soaks up water and is not useful for outdoor building due to the water retention. Standard hardboard is the basic strength and type of hardboard made out of wooden materials, medium hardboard is a stronger and thicker version of the standard hardboard and the oil tempered hardboard has oil added during the production process that makes it stronger, harder and more durable than the other two types. The main problem for hardboard is too much moisture because moisture will cause expansion and damage.
Apply a Waterproof Primer
Primer is the first step because it prepares the hardboard material. It provides the first layer of protection for hardboard from basic water damage or other liquids. The type of primer used will determine the exact amount of protection, but most provide basic protection against water. Primer is also used as a preparation for adding paint to the hardboard materials so that any color from the hardboard does not show through the paint.
Adding paint to the top of the primer adds an extra layer of protection while also providing a base color for the material. The type of paint will dictate what protection is provided. For example, a water soluble paint will not protect against water because it will melt away. Historic Homeworks recommends using a top heavy paint or a colored latex stain for protective purposes because the clear stains or light paints do not provide enough protection or durability.
Apply a waterproof coating. Waterproofing is an important part of protecting the hardboard material. The hardboard is susceptible to water which can cause expansion and damage. Waterproofing the material prevents the potential damage from water due to rain, soaking or any other potential situation where the board gets wet. Hardboard waterproofing has a few options: a waterproof sheeting material or an oil-based waterproof clear coat paint. The sheeting material is better for small areas of hardboard for cost efficiency and ease of application. The oil-based waterproof clear coat is better for larger areas of hardboard, such as an inside house wall.