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Can You Install Hardie Board Over Wood Siding

Common Siding Installation Question: Can You Install Hardie Board Over Wood Siding?

Common Siding Installation Question: Can You Install Hardie Board Over Wood Siding?

Is your home’s wood siding faded, rotten, worn out, or just plain outdated?

Are you dreaming of updating your home’s look and curb appeal?

Perhaps you’ve read all about the benefits of installing Hardie board but now you’re wondering…

Common Siding Installation Question: Can You Install Hardie Board Over Wood Siding?

In this article, we’ll cover …

  • What types of wood siding can be covered with Hardie board
  • The benefits of installing Hardie board over wood siding
  • Issues that may prevent installing Hardie board over wood siding; and 
  • The steps to covering wood siding with Hardie board

… so that you can finally live in the house of your dreams.


Table of Contents


Can You Put Hardie Board Over Wood Siding?

Yes and no

The answer depends on the type of wood siding you currently have. 

If you decide to install Hardie board over your wood siding, the existing siding becomes the substrate for the new Hardie board. 

Because Hardie board can last 50+ years, it’s important that the substrate meets few important requirements — most importantly, it has to be flat. 

Types of Wood Siding That Can Be Covered With Hardie Board

It is possible to use your existing wood siding as a substrate as long as the siding is in good condition and is flush, flat, and without gaps.

Some examples of flat wood siding that may work well being covered with Hardie board include:

  • T1-11 siding — T1-11 was a very popular wood siding option used from the 1960s through the early ’80s. It is simply a type of textured plywood, which makes for a great Hardie board substrate.
  • Tongue-and-groove siding — Tongue-and-groove siding is a versatile wood siding option that can be installed horizontally, vertically, or diagonally. The unique interlocking nature of the tongue-and-groove planks create a smooth surface that can be an ideal Hardie board substrate.  
  • Flat shiplap sidingShiplap siding is a popular style of wood siding. The rabbet, or groove, cut into both the top and the bottom of the shiplap allows the boards to fit snugly together. As long as the shiplap is flat, it makes a great option for being covered with Hardie board. 

Types of Wood Siding That Cannot Be Covered With Hardie Board

Many types of siding overlap or have large gaps as part of their design. These styles are not ideal for use as a substrate because they don’t provide the flat, smooth surface needed to achieve a finished look that is free from rippling or bowing.

It is not recommended that Hardie board be installed on top of wood siding such as:

  • Beveled siding — Also sometimes referred to as lap or clapboard siding, beveled siding is a traditional form of wood siding. Beveled siding is not recommended as a substrate for Hardie board because of the overlapping style of the boards. 
  • Drop channel siding — With the unique ability to be installed vertically, horizontally, or diagonally, drop channel siding is a versatile and popular wood siding option. It is not, however, a popular choice to be covered with Hardie board due to the drop channels created between the boards. 
  • board-and-batten siding — Commonly seen in older farm-style houses, board-and-batten siding consists of wide, wooden boards installed vertically with narrow strips of batten installed over the space between the boards. This batten strip creates a surface that is not conducive to the installation of Hardie board on top.  
  • Shake siding — Shake siding resembles shingles but they are thicker and more sturdy. Because the wooden shakes are usually not uniform in size and thickness and are installed by overlapping, it is not advised to install Hardie board over shake siding. 

Does Existing Wood Siding Need to Be in Decent Condition to Cover With Hardie Board?


It is very important that, in addition to being flush and flat, wood siding needs to be in decent condition to be covered with Hardie board.

But what does “decent condition” look like? 

To consider using your existing wood siding as a substrate, your siding should be in good condition and free from bows, warps, curls, or peeling pieces of siding. 

The siding should be sturdy and free of any other types of significant damages. 

Wondering if your existing siding is in decent enough shape to be covered? 

Call Elite Home Exteriors for your free, no-strings-attached estimate. 

We’ll come out to assess the condition of your siding and provide a consultation free of charge.

What Issues Could Prevent Hardie Board From Being Installed Over Wood Siding?

Almost all older siding will have some minor issues that might not be a big deal, but there are a few very significant issues that may prevent you from being able to install Hardie board on top of your existing siding

Some of these major issues to look for include:

  • Water damage — Water leaks or penetration issues lead to rotten siding and potential damages within the wall cavity and/or studs. It would not be advisable to install Hardie board over wood siding that shows signs of significant water damage. 
  • Pest damage — Wood siding that shows signs of pest infiltration, rodent nests, or holes from animals such as birds, squirrels, rats, or raccoons is not typically a good substrate choice. 

Hardiplank Over Existing Siding

Benefits of Putting Hardie Board Over Wood Siding

As long as your existing wood siding is flat, flush, and in decent shape, there are several significant benefitsfor both your time and money — for installing Hardie board siding directly on top.

Cost Savings

Using your existing siding as the substrate for your new Hardie board siding will present significant monetary savings often hundreds, or even thousands, of dollars — compared to the expense of removing the existing siding and replacing it with a new substrate material. 

Additionally, when compared to the upkeep required for wood siding, you may also see some long-term cost savings from the installation of Hardie board.

Time Savings

The process of … 

  1. Removing the old siding
  2. Disposing of the old siding 
  3. Buying transporting a new substrate, and
  4. Installing the new substrate

… can be time-consuming, taking anywhere from a few days to a week or more. 

And that’s all before you actually begin installing the new Hardie board siding. 

If your existing siding is in good enough condition to be used as your substrate, it’s a much more time-effective choice. 

How to Put Hardie Board Over Wood Siding: 6 Steps

If your existing wood siding is in good shape, installing Hardie board over it is actually quite fast and simple, consisting of just 6 steps.

#1: Inspect Existing Siding

Inspecting your wood siding is a crucial first step that should not be skipped. 

Although you may think that siding damage would be obvious and easy to spot, the truth is that damages under the paint can be much harder to detect if you don’t know what you’re looking for. 

Don’t set yourself — and your home — up for failure by cutting corners on this vital first step.

Elite Home Exteriors provides free, no-risk inspections as well as a free estimate for siding replacement or installation. 


#2: Complete Necessary Spot Replacements

If damaged or rotten places in the siding are identified, it doesn’t mean that all is lost. 

It’s possible that with a little repair work, your existing siding can still be used as a sturdy substrate for your new Hardie board siding.

Once a soft, rotten, or damaged piece of wood has been identified, it’s important to ensure that the damage doesn’t extend further into the wall or studs. 

As long as the damage is at surface level, it can be cut out and replaced with new, undamaged plywood.

Once all of the damaged areas have been identified and replaced, you can then move on to the next step in the installation process.

#3: Apply Weather Barrier

Once the substrate has been inspected, repaired, and prepped, it’s time to install the weather barrier.

Also known as a vapor barrier or house wrap, the weather barrier is a vital component for protecting your home, which is installed between your existing wood siding and your new Hardie board. 

Weather barriers, designed to protect your walls from infiltration of air and moisture, help increase the energy efficiency of your home. 

There are many categories of weather barriers used today, such as: 

  • Asphalt felt 
  • Grade D building paper
  • Plastic house wraps 

Regardless of the type you chose, it should be weather resistant as well as being UV resistant and should have a high tear strength.

#4: Properly Flash All Windows and Doors

Once the house has been fully wrapped in a protective weather barrier, it’s time to ensure that the windows and doors are properly flashed. 

Flashing is an important step to ensure that the window and door openings are protected from water damage. 

Proper flashing generally includes the following steps:

  1. Cut back the weather-resistive barrier
  2. Install the sill pan flashing
  3. Fold and tape the weather-resistive barriers flaps along the rough opening
  4. Apply sealant
  5. Install the window or door frame; and
  6. Apply window tape, if needed

Can You Install Hardie Board Over Wood Siding

#5: Trim Windows, Doors, and Corner

Once all of the openings have been properly flashed, it’s time to trim out the windows, doors, and corners. 

Installing trim is actually more simple than it appears. The steps include:

  1. Prepare the openings, jambs, and corners of the home
  2. Measure and mark the trim
  3. Cut the trim according to the measurements
  4. Install the window and door casings
  5. Install the corner trim; and
  6. Apply caulk as needed

#6: Install Hardie Board Over Wood Siding

Finally, it’s time for the grand finale of Common Siding Installation Question: Can You Install Hardie Board Over Wood Siding?

It’s time to have your new Hardie board installed over the old wood siding.

Because quality Hardie board is a bit of an investment, it’s generally a good idea to leave the installation to the professionals who can ensure it’s installed properly. 

Elite Home Exteriors is a James Hardie Preferred Contractor, so choosing us to install your new siding means you’ll get a 30-year non-prorated warranty on your James Hardie siding.

The steps you can expect your installation team to take may include:

  1. Marking and laying out of the siding courses
  2. Flashing the butt joints
  3. Measuring and cutting the fiber cement boards
  4. Installing vinyl mounting blocks around lights, receptacles, and vents
  5. Priming, painting, and caulking all cut edges
  6. Installing kick-out flashing

And finally, the job is done.

All that’s left to do is to step back and enjoy your beautifully updated house.

Wondering if Your Existing Wood Siding Can Be Covered With Hardie Board? Elite Home Exteriors Can Help

If you’re curious if you can install Hardie board over wood siding on your home, there’s no one better equipped to help you than Elite Home Exteriors. 

You can depend on us to always provide you with:

  •  Exceptional customer service
  • Top-notch workmanship; and
  • Competitive pricing

If you’re ready to find out just how beautiful your home can be, contact Elite Home Exteriors for a free estimate today. 



Posted on by PortlandSEOGrowth
Common Siding Installation Question: Can You Install Hardie Board Over Wood Siding?

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