James Hardie vs LP Smartside Siding Review

James Hardie vs LP Smartside Siding Review

When you're looking for replacement siding on your home sometimes the choices can be overwhelming. In this article, we will review two of the most popular siding products today, James Hardie and LP SmartSide lap siding.

Topics include:

What are James Hardie and LP Smartside products made of?

James Hardie Fiber Cement Siding

Let's begin with a basic analysis of James Hardie products, generally referred to as "Hardie" or "HardiePlank." James Hardie products are often referred to as "fiber-cement" products because of the materials that they are made out of.The main/bulk ingredient in James Hardie siding products is silica dust. The silica dust is combined with other materials such as wood fiber for strength as well as a number of other proprietary ingredients that are a closely guarded trade secret. One of the final ingredients is the cement which is the binding agent that holds everything together. The actual cement content of the finished product is relatively low, similar to the cement content in concrete. The resultant product is a very hard, albeit brittle, exterior siding product.

LP SmartSide Siding

LP SmartSide is made out of what LP calls an "engineered wood" product.

The first step in the process involves placing raw lumber through a wood chipper to create wood strands/chips that are somewhat uniform in shape & size. The wood strands are then fed through a mixing mechanism whereby all surfaces of the wood chips are coated with a mixture of waxes, resins, and Zinc Borate. The zinc borate acts as a preservative that wards off wood-rot & termites. After mixing/coating, the wood strands are laid down in interwoven orientations which results in dimensional stability in the finished product. The now loosely-interwoven mat of wood-strands is then fed into a press which does a few things simultaneously: it embosses a wood-like finish into the surface of the boards, it compresses the interwoven-mat into the final thickness of the desired siding product, and it uses heat to activate the binding agent of the material. 


How long are James Hardie and LP SmartSide boards?

This is one area where LP SmartSide excels. The boards are made in 16-foot lengths as opposed to James Hardie's 12-foot board lengths. The end result is 33% fewer seams on your home when the product is installed. 

James Hardie 

  • 12-foot board lengths

LP SmartSide 

  • 16-foot board lengths

What type of textures do James Hardie and LP SmartSide offer?

Both James Hardie and LP SmartSide offer a variety of different surface finishes on their products.

James Hardie

  • Custom Beaded Cedarmill
  • Custom Beaded Smooth
  • Select Cedarmill
  • Smooth

LP SmartSide

  • Cedar Texture Lap
  • Colonial Beaded Lap
  • Smooth Finish Lap 

What finishes do James Hardie and LP SmartSide offer?

Both James Hardie and LP SmartSide offer products with primed finishes that are ready for painting after installation

James Hardie

  • Hardie ColorPlus Pre-Finish ( JH factory applied)
  • Primed

LP SmartSide

  • Factory Pre-Finished through Diamond Kote (3rd party applied)
  • Primed

Diamond Kote offers a variety of standard colors (similar to Hardie ColorPlus). They also offer a 2-tone pre-finish that they refer to as Duoblend Premium.

The Duoblend Premium finish mimics the look of real wood, allowing one to sheath their home in a product that looks like wood yet has the additional insect & rot-resistance of the LP SmartSide siding product.

Does James Hardie or LP SmartSide offer a better warranty?

James Hardie

  • 30-Year Limited Warranty

LP SmartSide

  • 50-Year Limited Warranty

What are the most common complaints/issues with LP SmartSide siding?

Not every product is perfect, here's a few issues with LP SmartSide: 

1. Price

Generally more expensive than James Hardie products

2. 3rd Party Involvement

No factory-pre finish offered; finishes are applied through 3rd party

What are the most common complaints/issues with James Hardie fiber cement siding?

Here we will list a few of the items going against James Hardie:

1. Silica Dust

As stated previously one of the main ingredients in James Hardie's siding is silica dust.

Like asbestos, when silica dust is undisturbed/NOT airborne, the material poses very little risk. And just like asbestos, silica dust is a known carcinogen.

When airborne, silica dust can cause a myriad of issues including but not limited to lung cancer. When James Hardie's products are cut with a saw, the silica dust becomes airborne.

This is not necessarily a problem for homeowners getting the product installed however it can become a problem for the technicians installing the product.

Best practices dictate that a respirator is worn when cutting the product on the job site however this precaution is rarely followed.

It is this authors' estimate that at some point in the future products containing silica dust will be banned, similar to asbestos.

2. Brittleness

James Hardie products are very hard however with that hardness comes brittleness.

People commonly refer to James Hardie products as concrete siding, however, this is not true.

One of the ingredients in James Hardie products is cement, an ingredient common in concrete but not the same thing as concrete.

Finished James Hardie product is similar in its physical properties to ceramics. It is extremely hard but if hit with a sudden impact the material will shatter.

This can be particularly troublesome in areas where hailstorms are common.

Hail damaged James Hardie products are NOT covered by their warranty.

3. Efflorescence

This is basically the migration of salts to the surface of a porous material, where it forms a coating.

There is really nothing that can be done to prevent this and it is not covered by the James Hardie warranty.

Pressure washing or an acid wash to the material seems to be the only remedies and the material would then need to be painted after being treated for efflorescence. 

4. Difficult to Work With

James Hardie products are notoriously difficult to deal with.

Special (more expensive) saw blades are required to cut the product and wear out at a much faster rate than typical wood-cutting blades. 

Installation guidelines must be meticulously followed else any future warranty claims will be denied due to improper installation:

A) Field-cut pieces must have their field-cut ends properly painted/sealed prior to installation. This often means that 100s of field-cut ends have to be sealed before installation

B.) Because of James Hardie's aforementioned brittleness, special care must be taken when handling the product. 12-foot lengths of HardiePlank siding snapping in two whilst being carried is a common occurrence.

After seeing some of the product information side-by-side, we hope it's easier to make your decision.


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