Can Hardie Board Get Wet? (Read This First!)

Building your house seems to be fun, but it soon turns into bewilderment when you see all the alternatives lying around. We all know about the amazing benefits Hardie boards provide us but are Hardie boards really waterproof?

Stay tuned so you don’t make any unforgivable mistake with Hardie boards.

Can Hardie board get wet?

Yes, Hardie boards can get wet if they are soaked in water for months. Hardie boards do not get wet when they’re installed on the wall. But the boards absorb water when they are put uncovered, flat on a surface. It takes a considerable amount of water to make Hardie boards wet.

Hardie board siding is proven to increase the value of your household. And who does not love the longevity of their products? With its low maintenance cost, lasting color, and unmatched warranty, Hardie boards have become a common choice for household owners.

Hardie backer boards are incredibly durable and can survive in the most intense weather. It has a sturdy water-resistant ability. Strong winds, hail, storms do not damage Hardie boards.

But the problem arises when Hardie boards are left flat on surfaces for months. They begin to absorb moisture. Likewise, cement boards are not waterproof. They may resist water, but prolonged exposure to water or moisture will damage their internal materials.

Hardie board before painting:

Hardie boards should be dried out before painting. Painting on wet Hardie boards distorts the board’s texture. You will get a different hue of paint once it dries out.

It is better to dry Hardie boards before painting to save yourself further struggle,

Hardie board before installation:

You should not install wet Hardie boards. They swell as they soak some water. Drying causes shrinkage, so installing wet Hardie boards will leave out spaces once it dries. The surfaces will peel off.

This will require further costs and installation.

Drying Hardie boards takes little to no effort. Just leave the boards outdoors in direct sun, and they will be ready for use in two days.

What happens if the Hardie board gets wet?

Hardie boards will swell up, causing their shape to deform. Some amount of discoloration can be expected. Excess water is detrimental for Hardie boards. Delamination occurs as the water gets inside layers and weakens the glue.

But it does not eradicate the integrity of the board. After drying out, you can use the board as if nothing happened to it.

Is Hardie board water-resistant?

Yes, the Hardie board is water-resistant. It endures heavy rain to storms. You can even install Hardie boards during light showers. It is water-resistant as long as it is installed on walls. Idle Hardie boards will soak water if put in a damp condition for long.

Does Hardie board need sealing?

Generally, Hardie boards do not require sealing. The boards are water-resistant enough to live for years enduring storms and rains. But the places that come with constant contact with water need sealing like using Hardie boards in showers or indoors will require sealing.

Otherwise, water will peep through the layers and damage them.

Can Hardie board be used outside?

Yes, Hardie boards are absolutely fine to use outside. Hardie board sidings can withstand any sort of weather condition. They are best known for their persistent durability across harsh climates.

Another advantage is that Hardie boards are non-combustible. They will not catch fire if installed following National Evaluation Report. (NER-405)

Will rain hurt Hardie board?

Hardie boards are water-resistant. That is, the boards are made to tolerate harsh weather conditions such as storms and rains. After installation, you can stay without any worries cause rain will not hurt your Hardie boards.

But beware when handling wet Hardie boards before installation. Dry out wet Hardie boards to reduce complications.

How to maintain Hardie plank siding?

Its unmatched warranty made Hardie sidings synonymous with durable, long-lasting. Lower maintenance cost is one of their significant advantages. But you still have to maintain Hardie plank sidings to maintain the beauty and value of your house.

Maintenance greatly depends on the location your house is situated in. Weather condition also contributes to maintenance style.

Here are some ways you can maintain Hardie plank siding –

Water and brush:

Wash your Hardie plank siding every 6-12 months to remove dust and dirt that have settled on the exterior surface. You can use a garden hose, and a soft-bristled brush, or a soft wet cloth. Wipe in the direction of plank siding, side to side motion.

Pressure water:

You may use low water pressure spray and a soft-bristled brush to clean fiber cement sidings. Brush in a side-to-side motion.

Beware while using water pressure because high water pressure will damage your siding. Keep a minimum of 6 ft distance, and water pressure should not rise above 1500 psi.

Detergent for stains:

You can use mild detergent and a soft-bristled brush for hard-to-remove stains that you couldn’t remove with water. Clean in small sections until the stubborn stain comes off. Do not use harsh detergents.  

Trim shrubs and bushes:

Make sure shrubs and herbs are away from home and siding. These plants could cause molds. Trim them if required.

Gutters for rainy weather:

Gutters will save your sidings from excessive rainwater. Installing gutters increases Hardie plank siding’s longevity by far.

Manufacturers’ suggestion on repainting:

Hardie plank sidings typically require repainting after some years. So before painting, read out the manufacturer’s recommendation on selecting proper paint. You can also paint Hardie planks sidings to cover up minor nicks and scratches.

Maintaining Hardie board sidings is not rocket science, but you can still hamper Hardie sidings with some forbidden products. Always avoid using any acid solution to clean Hardie plank sidings as they damage the surface. High water pressure damages Hardie plank sidings surface.

Metal scrubber should be a no because it damages the siding’s texture. It is not suitable for Hardie plank siding’s surface. Avoid oil and alkyd-based paints. These paints further damage Hardie plank sidings.

How often does the Hardie board need to be painted?

Hardie boards don’t require much painting. After installation, you don’t have to worry about repainting for about 10 to 15 years. Hardie board paints have a lifespan of 5 to 15 years as long as the paint is applied correctly and there is no external damage.

After that period, the paint will start to fade or chip, so you should keep regular check-ups for minor nicks, scratches, and cracks. You have to paint more frequently if the weather is too harsh for households.

Does Hardie board get mold?

Yes, Hadie boards can get molds if it is constantly exposed to water. Keep water sprinklers away from Hardie boards. Wet soil and ground around Hardie boards will cause it to grow molds and mildew. Warm weather and high humidity are also a reason for molds to grow.

Get yourself a mask and gloves. Use mild detergent and a soft-bristled brush to get rid of molds. Gently brush away the mold with mild detergent and rinse it with a garden hose. Do not overdo the cleaning because it may damage Hardie boards.

How long can Hardie board go unpainted?

There is no hard and fast rule on painting Hardie boards. Painting depends on the location of the house and weather conditions. A higher amount of rain and little shades will cause the surface to deteriorate soon.

Usually, your Hardie boards will do fine, about 4-6 years unpainted. But this depends on place to place.

Once the surface starts to deteriorate, it will be hard to cover it with paint. There will be rough spots visible. A helpful rule of thumb is to paint Hardie boards before installing. It is much easier this way.

How long will Hardie board last?

Hardie boards have an average lifespan of 30 years. But this number varies for factors such as maintenance, humidity, and climate. Warm weather and high humidity often reduce the life of Hardie boards.

But with proper care and maintenance, your Hardie boards can last up to 50 years. Check for molds, paint when necessary, and clean occasionally, and your Hardie boards will reward you with long-lasting longevity.

Final thoughts

Waterproof and water-resistant are two different things. Hardie boards will repel water, but it gets wet if exposed to water for a prolonged time. Staying a little cautious while handling them will save you from great upsets. Store with waterproof cover, and if wet, dry out before using.