Although vinyl is impervious to water when installed as directed by the manufacturer vinyl siding as a whole is not completely watertight.
Vinyl siding chimney leak.
Use a caulking gun to apply a continuous bead of silicone sealant along.
Vinyl siding installs in pieces so gaps and overlaps.
Check to be sure weep holes are open along bottom of window openings.
My photo above of ice below some courses of vinyl siding traces a moisture problem traced to improper installation of a through wall vent for a direct vent heating.
If an installer uses a material such as incorrectly this only exacerbates the problem.
Leaks into siding at gaps or damage points most of the vinyl siding problems we see appear to be due to poor installation details though on occasion we see cracks and breaks that may be blamed on older more brittle vinyl products.
In this video this old house general contractor tom silva shows how to prevent water from leaking in behind vinyl siding.
Video of the day.
Vinyl siding is designed as an exterior cladding only and is supposed to be installed over other materials such as a weather resistant barrier.
Vinyl siding on chimneys vinyl siding is generally not recommended for exterior chimney siding because of the heat that the chimney produces.
Water leaks at soffit or eave overhang penetrations for chimneys that permits water to leak at the roof surface then pass behind the siding if the chimney is not properly flashed.
Installation gaps in siding of any type if not back flashed invite leaks into the wall above left.
Inspect the area above the leak including both indoors and out.
To repair leaky siding you can use exterior caulk to fill in any small cracks.
Although most town codes require a waterproofing barrier such as tyvek to be installed we come across plenty of chimneys where no water barrier was installed or it was improperly installed.
Vinyl is a potentially leaky material and water trapped behind siding leads to decay and mold.
You ll want something strong like bondo or quickwood.
Even if the siding or stucco is properly installed if the components above it like the chimney chase or chimney cap fails the leak will cause damage.