Fiber Cement or LP SmartSide Siding? An Asset or Liability with Single or Double Wall Construction Houston Texas Department of Insurance “TDI”?

With my many years of construction background of building homes, I along with many other home builders and remodelers, know the value of building a strong home. Here in the southeast Houston Texas metro area we have a good amount of wind and with our being so close to the coast, we are also vulnerable to hurricanes.

Wind Racking Force on Homes

There are two forces a homeowner should be concerned with, or should I say, anyone that lives in wind-prone areas of the USA. One is “uplift force” and the other is “racking force” from shear wind blowing directly at any home or structure.

We will be talking about Racking Force in this siding post because it is a concern many homeowners should be aware of. Right around the year 1999 here in Houston Texas many homeowners were being pitched and marketed to move away from vinyl siding and installing, in its place, fiber cement siding.

The installation of this product often meant removing the old wood siding, stripping the OSB or  plywood sheathing down to the studs and installing the installation of the new fiber cement product. In the photo below, you can clearly see how builders across the country will often build diagonal “let-in” bracing (per the green arrows in the photo) into a home to help combat the racking force caused by shear wind. Single wall construction is when the siding is applied directly to the studs without any sheathing like OSB or plywood first. Single wall construction with fiber cement siding is perfectly fine for non- wind/non-coastal areas of the country as displayed in the photo below. However; for high wind areas, more than diagonal “let-in” bracing is needed as per Texas Department of Insurance TDI Wind department hence, double wall construction with OSB or plywood sheathing is required to be installed before siding for added strength.

Let In bracing “diagonal bracing” a home helps combat the racking force caused by shear winds in Houston TX

The best practice of using the diagonal bracing will help stop any home from racking (tilting) when strong winds are blowing. Builders will often install OSB or plywood over these outside walls by nailing them to the exposed studs as can be seen on the left side of the diagram below labeled “Wind Areas/ Houston Double Wall Construction“. Once the OSB or plywood is installed, the builders install siding over that plywood layer. By having this base layer, consisting of some sort of OSB or plywood sheathing attached to the the studs of any outside wall, gives the home increased strength and shear wind resistance to combat racking force. This method is called “double wall construction“.

Coming from my many years of experience from using and knowledge of fiber cement, I have found it to have very little structural value and it can break easily. The product offers little structural support (if any) to the outside of a home and can in fact be a liability. Don’t believe me, but try taking a hammer and moderately hitting the Fiber Cement siding, and see for yourself how easily it breaks and crumbles to the ground. I was in shock back in 1999 in Houston Texas as I observed (even participated in) siding contractors removing lap wood siding and T-111 vertical siding ultimately affecting the structural value which had been an asset to the home. This was then replaced with the installation of fiber cement which without installing any OSB or plywood, offered nearly no structural value.

Movement of the home can cause cracking of the fiber cement siding.

The image on the right is of a home I received a call on that was a “call back” from an installation by another siding contractor who had removed the old wood siding and did not install any OSB or plywood under the newly installed Fiber Cement.

The result was that the home moved causing cracking of the fiber cement allowing water intrusion and causing other problems.

This Houston TX homeowner will continue to have movement problems until all of the fiber cement siding is removed and some sort of structural grade of sheathing is installed like OSB or plywood.

Keep in mind that this homeowner paid over 14k for a siding job that was done incorrectly. In Texas, homeowners often experience movement in their homes, this is yet another reason to install OSB or plywood sheathing before any fiber cement siding is installed, hence, the method of installing double wall construction will add more stability to Houston TX homes.

The best way to build strength into the exterior of the walls is with double wall construction.

The diagram below shows how to correctly install the layers (sheathing like OSB or plywood – double wall construction) prior to installing the fiber cement siding to help increase any home’s structural value for both shear, racking force wind and any settling movement providing increased strength to the exterior walls of the home. Keep in mind that this is a much better re-siding approach for homeowners when removing old structural grade siding and installing fiber cement siding in its place.

This is the best way to build strength into any outside wall for homes in coastal areas that are going to be sided with fiber cement siding.

Keep in mind that if you do choose to side your home with single wall construction, a propelled airborne object could quite easily come right through fiber cement siding, the insulation and sheetrock and enter your home!

When building or if you are re-siding your home and it has no OSB or plywood under the siding, single wall construction, I recommend using the LP SmartSide Siding due to its proven brute strength. This siding will be an Asset to the integrity of your home’s exterior walls and will help keep those that you love safer inside your home. You do NOT need to install OSB or plywood sheathing before installing the LP SmartSide product and racking force from shear wind becomes much less of an issue due to the increased strength of the exterior walls. LP SmartSide Siding actually takes the place of OSB or plywood and provides much structural value and looks great too.

The must-see video below explains clearly what this means for your home. Fiber cement siding, is a great siding option, however; please insist that your siding contractor install double wall construction with OSB or plywood first for the structural integrity of the building.

The moral of the story is this:
Fiber Cement Siding Installed on Single Wall Construction = a Liability.
LP SmartSide Siding Installed on Single Wall Construction = an Asset.

~Greg Kapitan (Kapitan the Siding Man)

Featured Video: Demonstration of LP SmartSide vs Fiber Cement Durability