Everyone talks about how to install James Hardie siding. How great the product is. How durable it is. And on the other side — how it can crack, how paint can fail, how moisture can become a problem over time.
What almost nobody talks about is the part in the middle — how to take care of it.
Here’s something every homeowner should understand: there is no exterior siding product on the market that requires zero maintenance. Not James Hardie. Not vinyl. Not wood. Not anything. Every exterior surface on your home is exposed to UV, rain, freeze-thaw cycles, humidity, and biological growth — and every one of them benefits from regular attention. The difference with James Hardie is that a little maintenance goes a very long way. It’s a significant investment in your home, and like any significant investment, it rewards the homeowners who take care of it.
Here’s what that looks like in practice.
Soft Wash Twice a Year
The single most impactful thing you can do for your James Hardie siding is soft wash it twice a year — once in the spring after pollen season and once in the fall before winter sets in.
Soft washing is low-pressure washing with a cleaning solution — not pressure washing. Pressure washing at high PSI can drive water behind siding, damage paint, and force moisture into areas it has no business being. Soft washing uses the chemistry of the cleaning solution to do the work, not the force of the water.
For a homeowner-friendly cleaning solution, mix a small amount of Dawn dish soap with white vinegar and water. Apply it to the siding surface, let it sit for a few minutes, and rinse with a garden hose or a low-pressure setting on your sprayer. This combination cuts through dirt, mildew, pollen, and biological growth without damaging the paint or the substrate.
Work from the top down so dirty water doesn’t run over areas you’ve already cleaned. Pay extra attention to areas under eaves, around windows, and at grade level where dirt and biological growth tend to concentrate.
Keep Touch-Up Paint on Hand
This is something we tell every IES customer at the end of every James Hardie installation — make sure your contractor leaves you touch-up paint before they wrap up the job. If they don’t offer it, ask for it.
Here’s why it matters: James Hardie is a painted product. The paint is what seals the surface and keeps moisture out of the substrate. A scratch, a chip, or an area where the paint has worn thin is an open door for moisture. Left unaddressed, that moisture works its way into the fiber cement over time and creates the exact problems — swelling, cracking, paint failure — that people associate with siding going bad.
None of that has to happen. A small chip takes five minutes and a brush to fix. Walk your siding once a year — spring is a good time — and touch up anything that looks like it’s lost its paint coating. It’s the cheapest maintenance you’ll ever do and it protects one of the biggest investments on your home.
Clear the Base of Your Siding at Grade Level
The lower elevations of your siding take the most abuse — and they’re the area most homeowners pay the least attention to.
Snow and ice that pile up against the base of your siding in winter will wick moisture upward into the bottom courses as they melt. Mulch, soil, and landscaping debris that sits against the siding at grade creates a constant source of moisture contact and biological growth. These are the areas where you’re most likely to see paint failure and moisture issues develop over time.
A few simple habits prevent most of this:
- Keep mulch and soil pulled back at least 2 inches from the base of your siding
- Clear snow away from the base of your home after significant snowfall — don’t let it pile up and sit against the siding
- Make sure your gutters and downspouts are directing water away from the foundation and not splashing back up onto the lower courses of siding
- Trim back any landscaping that sits against or overhangs the siding — airflow matters
James Hardie is engineered with a clearance requirement at grade level for a reason. Maintaining that clearance in the field is the homeowner’s job once the siding is installed.
Check Caulk Joints Annually
Caulked joints at windows, doors, corners, and penetrations are the other area worth a quick annual inspection. Caulk ages. It shrinks, cracks, and eventually loses its seal. When that happens, water finds its way behind the siding at exactly the points where it’s most likely to cause damage.
Walk your home once a year and look at the caulk joints. If you see cracking, separation, or areas where the caulk has pulled away from the surface — recaulk those spots before winter. It’s a small job that prevents a large one.
The Bottom Line
James Hardie siding is one of the best exterior investments a St. Louis homeowner can make. It’s engineered specifically for our climate, it holds paint longer than wood, and it doesn’t rot or attract insects. But it is not a zero-maintenance product — and any contractor who tells you otherwise isn’t being straight with you.
Soft wash it twice a year. Touch up the paint when it chips. Keep the base of the siding clear. Check the caulk. Do those four things and your James Hardie siding will look and perform the way it’s supposed to for decades.
If you have questions about your existing Hardie installation or you’re thinking about a new one — IES Construction & Roofing is a certified James Hardie installer serving St. Louis and Metro East Illinois. We’re happy to take a look and give you a straight answer.