Water Getting Behind Siding

Rainwater leaking from a gutter ends up behind siding and causes a wall to rot.

Water getting behind siding.

The extra thickness of the vinyl. If the builder failed to install a weather barrier this sort of staining is more likely. This will result in eventual water damage either by absorbing into the siding or getting behind into the sheathing or frame. This is most prominent in j channels that run horizontally such as trim running along a window frame.

In most communities building codes require a moisture barrier. At some point in the past an owner had vinyl siding installed over old siding. Water should not be allowed to run down the siding. As gravity takes over and pushes the rainfall downwards you better hope your siding was installed correctly.

Tracking down the leaks in a vinyl sided building. The problem with j channels is that when improperly used or installed they trap water and can provide an entry point for water to get behind the siding. Inspect the area above the leak including both indoors and out. Water passing over wood and other building materials but behind the vinyl siding can easily pick up pigments that stain the foundation wall outside.

The shingles should be hanging about 1 4 inch to 1 2 inch beyond the drip edge so this may be your problem. Water damage often occurs near corners and edges and caulking in these places keeps moisture from seeping beneath siding. Water runs down the siding and can collect in the j channel. See water barriers exterior.

Any inconsistencies in siding such as cracks nail holes and the like should also be caulked. In this video this old house general contractor tom silva shows how to prevent water from leaking in behind vinyl siding. This also applies to trim boards and wooden window frames. However it is possible for water to get behind the siding if it s not installed properly.

The flashing keeps water off the sheathing and drains water properly which prevents water damage. Preparation for siding while correct installation reduces the risk of water running behind the siding it can t completely stop it. Bottom to top rain will hit the roof and make its way down your siding until it hits the ground. Remember one of the main hardie siding problems is water damage however it s also one of the easiest to prevent with proper installation.