Hardie Siding Installation 101 (Part 2)

Artisan James Hardie

This article is the second edition of Hardie Siding Installation 101. The intent of this post is to provide Carolina homeowners with the installation specifications that the manufacturer mandates and many contractors neglect. Failure to comply with the below specifications can lead to premature product failure.

Horizontal Breaks

Horizontal Breaks refer to any area above a window, door or mounting block.

Hardie Siding must be installed with a ¼ inch gap above all Horizontal Breaks. This includes all windows, doors, mounting blocks, etc. The gap needs to incorporate Z-Flashing with a 15-degree downward slope. Caulking the gap will not allow water to properly enter and exit the siding façade. This can cause rot, mold, mildew and premature deterioration of a home’s exterior components.

Clearance Treatment

Clearance treatment refers to the area where the siding of a home meets it’s foundation or water table.

Hardie Siding will be installed with a ¼ gap on all wall clearances. The gap needs to incorporate Z-Flashing with a 15-degree downward slope. Failure to integrate a ¼ clearance can lead to paint failure and premature deterioration of all bottom course planks.

Trim to Plank Clearance

Trim to Plank Clearance is the area where Hardieplank siding meets HardieTrim.

Hatch Homes will meet all of James Hardie’s requirements when it comes to Trim and Plank spacing. The manufacturer mandates that a 1/8 inch gap is left between Siding & Trim on the Inside and Outside Corners of a home. That space is to be caulked with moisture resistant, flex caulking.

Trim Caulking

Hatch uses OSI Quad Max Caulk, which is recommended in James Hardie’s installation regulations. OSI Caulk is color matched to Hardie’s ColorPlus product line. Setting OSI caulking with your finger goes against manufacturer specifications as the oils in our skin will eat away at the unset caulk. Our Certified Siding Technicians have extensive experience with caulking James Hardie Siding Products. The workmanship of an unexperienced caulker will lead to a poor finished aesthetic where your siding meets trim.

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