It is a common misperception that exterior siding such as vinyl, wood, aluminum, brick, stone, fibre cement and others are intended to keep all water out. In actual fact, wind and/or solar driven rain will penetrate all exterior wall cladding systems and that is perfectly normal. The only possible exception might be “face sealed” systems such as EIFS (Exterior Insulation Finishing System) but these assemblies are only effective at keeping water out if the sealant around openings such as windows and doors is properly maintained, which is rarely the case.
So, where does the water go once it passes through the face of the wall cladding? Well, that all depends on how the wall was constructed. If the siding material is affixed directly to the wall sheathing with no airspace provided, the water will be trapped between the back of the siding and the WRB (weather resistant barrier) or sheathing paper. Water can build up over time and in more humid climates, it may never completely go away. If that happens, deterioration of the building materials the water comes in contact with can result; that’s when the trouble starts. Many materials used in construction such as wood, insulation, fibre cement, brick, gypsum board, etc are highly absorptive and therefore also susceptible to rot.
The solution is to apply ventgrid12 behind the cladding to provide a ventilated and drained airspace allowing water to escape and air to flow through and dry out the materials in the wall assembly. Ventgrid12 is strong, rigid, easy to use and affordable.
Consider the high cost replacing the siding on your home or, worse, repairing damage caused by rot in the wall assembly and ventgrid easily becomes an important and affordable investment in preserving the beauty of your home.