Gaps Between Hardi Plank Siding

It is also difficult to achieve the specified gap in the horizontal overlap.

Gaps between hardi plank siding. When james hardie siding products butt into wood based materials a 1 8 gap will allow for expansion and contraction of the wood based product. 10 years ago the installation directions called for an 1 8 gap and then caulk. Remember that most hardie siding problems are caused by improper installation. The bottom of the siding should be kept even with the bottom of the trim or if desired the trim may extend below the bottom of the siding.

Always prime or paint any cut edges that are inserted into a window j channel. Flashing installed incorrectly or siding installed without the proper gap between the siding and flashing will both result in water damage and a voided warranty. When james hardie siding products butt into wood based materials a 1 8 gap will allow for expansion and contraction of the wood based product. Gap between the siding and trim.

When installing the first course make. Vertical trim gap caulking. If siding butt joint gaps are due to shrinkage the central problem is one of shrinkage that occurs principally if the siding was not stored properly prior to installation particularly if it got wet. James hardie recommends butting field joints together in moderate contact to achieve a continuous looking joint.

Do not caulk between siding and any built in receiving channels located at or around windows. High moisture at time of installation is going to give gaps. But the siding should never hang below the trim. Always caulk between the siding and the trim.

The boards would shrink a little bit making the gap 3 16 to 3 8 depending on how much moisture was in them and how close the install gap was to 1 8. James hardie recommends the use of caulks and sealants that remain permanently flexible. 3 8 from plank edge leave 1 8 gap between plank and trim then caulk weather resistive barrier plywood or osb sheathing. This is a common mistake and so easy to avid.

James hardie recommends the use of caulks and sealants that remain permanently flexible. Double wall construction single wall construction. During my time working for james hardie i very rarely got calls from homeowners that wanted to submit a warranty claim for their hardie siding. Run the siding to the hardietrim board leaving a 1 8 in.

Leave a 1 8 gap between the siding and the trim or other materials to allow for structural movement.