Caulking Hardiplank Lap Siding

Flashing acts as a waterproofing layer for this type of siding and caulking will prevent the flashing from doing its job.

Caulking hardiplank lap siding.

It will look okay on day one but caulk is not designed to be used as a touch up and it will weather at a different pace than the siding. Similar to paint previous coats of. Joint flashing is recommended for all hardie lap siding now. James hardie color match caulk osi quad caulk for exterior door window and siding applications color matched to james hardie colors uv water resistant will not crack or yellow 1 tube covers 29 lineal feet at 1 4 bead width or 13 lineal feet at a 3 8 bead width paintable.

The nails holding up the siding should not be caulked. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. Lastly james hardie does not allow the use of colour matched caulking for touch ups. Osi quad product brochure.

James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2. This video is about how to like a pro. A diyer or a novice painter might attempt to achieve a cleaner look by caulking the siding nails but the nail is guaranteed to push the caulking material out within a few months. Apparently no one here read the technical bulletin 9 that james hardie released in 2008.

Deterioration of the caulking in the joint has become a maintenance issue for home owners over time. Is the old caulking removed before new coats are applied. Many professionals like those at james hardie also agree that you should not use caulk on fiber cement siding unless there is no metal flashing underneath. Joint flashing butt joint horizontal lap treatment june 2014 james hardie does not recommend caulking butt joints or the horizontal overlaps joint flashing 6 in.

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. 25 4 mm on overlap no caulk figure 1. Hardie no longer recommends the caulking of any joint in their lap siding colorplus or primed.