Caulking Between Hardiplank Siding

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.

Caulking between hardiplank siding.

2 house built before 2008 so has no flashing okay to caulk. But here the main problem is people usually don t find the right type of caulk for their works. The nails holding up the siding should not be caulked. Always prime or paint any cut edges that are inserted into a window j channel.

Vertical trim gap caulking. 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. Osi quad product brochure. Always caulk between the siding and the trim.

If you use sashco s acrylic latex caulking sealant you can have any interior or exterior as good as new. Hardie plank siding has a nail line across the top of the board that is 1 down from the top and nails are supposed to fall between and 1 from the top of the board to give the best hold. Hardie no longer recommends the caulking of any joint in their lap siding colorplus or primed. Leave a 1 8 gap between the siding and the trim or other materials to allow for structural movement.

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. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. Flashing acts as a waterproofing layer for this type of siding and caulking will prevent the flashing from doing its job. 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.

Joint flashing is recommended for all hardie lap siding now. 25 4 mm on overlap no caulk figure 1. James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2. Deterioration of the caulking in the joint has become a maintenance issue for home owners over time.

1 i chose this caulk because it has 25 flexibility compared to silicone based caulk. 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. 152 4 mm wide 1 in. Is the old caulking removed before new coats are applied.

Apparently no one here read the technical bulletin 9 that james hardie released in 2008. You need to have the best caulk for hardie siding to help your walls and wooden surfaces to get rid of open cracks and thin spaces between joints.