Although i do not understand why they have not changed the information about caulking in the instruction manual.
Caulking siding joints.
It is generally not a good idea to use caulking on wood siding.
James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2.
While as a diyer you might be obsessing about your caulking skill truth be told that will not matter if you don t have the right caulk.
Generally we do not recommend caulking butt joints on cedar siding.
There s no way around regular maintenance of those siding butt joints unless you want to completely remove the siding and install joint flashing.
Joint flashing is recommended for all hardie lap siding now.
25 4 mm on overlap no caulk figure 1.
Sometimes the old caulk in the siding joint is cracked and you need to cut the old caulk out with a razor knife.
Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur.
If the siding joint is so tight that the caulk only bridges the gap it may split again.
These siding joints can be caulked successfully if the gap is wide enough for the caulk to get into the crack.
Deterioration of the caulking in the joint has become a maintenance issue for home owners over time.
152 4 mm wide 1 in.
If overused or incorrectly placed siding caulk can cause more damage to your exterior than good.
Those joints need to be protected somehow.
Should they always be caulked.
Where two pieces of siding meet.
Apply these strips in place of traditional caulk or over already caulked joints for a finished appearance.
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.
The answer depends on the manufacturer and installation method used when the siding was first installed.
Caulk backer rods are lengths of foam that help fill large gaps before caulking.
Natural siding boards are designed to expand and contract.
Butt joints but not all butt joints.
When deciding how to use caulk on your siding however it is generally more important to consider where you should not use it.