Over the years, I’ve seen all kinds of water leaks that homeowners think are caused by failing siding.

But what really protects your home’s interior from leaks is the flashing and house wrap under the siding. This is called the siding envelope.

Next time you see a home being built or remodeled, look at the material that is being wrapped over the plywood exterior (before the siding is installed). Most times, it will be some variation of sheet wrapping that is stapled down (hopefully) over the metal flashing. This is a proven system that works. I’ve seen 100-year-old homes with tar paper that still works if it does not get opened up and disturbed.

House leaks are caused by incorrect installation of the siding envelope.

When water gets behind siding, it’s looking for a way to drain (hopefully to the exterior!)

When a window or door is installed, the water behind the siding stops flowing and pools. If the house wrap is installed over the metal flashing above that window or door, it will escape outside over the drip edge flashing, If the wrap is behind the flashing, it will flow behind the flashing and into the wall framing and eventually into the house.

When water cannot escape it will rot your framing.

Snowridge has repaired many a rot-damaged home, and we’ve used different house wrap products, but our preferred system is a roll-on liquid membrane called Prosoco. It has several important advantages over regular house wrap. Prosoco requires no staples or overlaps. It completely coats the surface and breathes, so there are no condensation problems. The metal flashing becomes part of its system and lets water escape like it should.

We believe it’s one of the best products we’ve used. This video will give you an idea of how we install it.