Clean the hole or depression you plan to fill.
Caulking split in siding joints.
Apply the compound to the hole or depression in one direction.
While paint does tend to somewhat glue these pieces together caulking them is never advised and can cause permanent damage.
A gap of 1 8 of an inch to 3 8 of an inch is necessary for the caulk to get into the crack and produce a good joint.
To patch holes and depressions in siding of any kind follow these steps.
Bottom of siding boards should not be caulked water is meant to exit through the bottom of each board.
Fill the area with patching compound.
A high quality paintable caulk is recommended.
The surface must be clean of dust and chalky paint.
Butt joints are a perfect example of poor joint design they re too small to accommodate a bond breaker so the caulk can t stretch properly once applied but they re also too large to simply leave alone.
These siding joints can be caulked successfully if the gap is wide enough for the caulk to get into the crack.
Some of the most commonly caulked areas of siding include both corners and crevices as well as some butt joints and window and door trim boards.
Sometimes the old caulk must be razor cut from these butt joints.
Your house s siding naturally expands and contracts and caulking it all together prevents this movement.
Water can seep in around butt joints and trim so these areas need to be caulked.
Sometimes the old caulk in the siding joint is cracked and you need to cut the old caulk out with a razor knife.
Do not caulk the underside of your siding i e caulk each piece of siding to the one beneath it.
The alternative is to use a joint molding in place of caulk.
It depends on the option you choose but if joint caulking option is selected seal all gaps at butt joints with a high quality exterior sealant meeting the astm c920 minimum class 25 sealant.
You can also use caulk to repair cracks in your siding.
This allows for the caulk to get in and fill the gap correctly.
Siding caulk can be used on several different areas of your exterior siding to help prevent water damage and moisture buildup.
For regular hardiplank lap siding the kind you paint after installation caulking at butt joints is optional.
If the siding joint is so tight that the caulk only bridges the gap it may split again.
So just to review.
This from installation instructions.
Caulking them is a mistake and the caulking is likely to fail prematurely.
This is where the siding in the middle of the wall butts up against another piece of siding.
Another critical place is where the siding butts together in the middle of the wall.
A caulk must be high quality in order to have the elasticity and adhesion necessary.
