What is flashing in cavity wall?
The flashing component is important. Its main purpose is to direct water out of the cavity. Flashing systems in cavity walls are typically located close to the base of the wall, so that it will collect the water that goes down the wall.
Where should flashing be installed in a masonry wall?
Flashing must be located beneath the first course of masonry above the finished ground level above the foundation wall or slab and at other points of support, including structural floors, shelf angles, and lintels when masonry veneers are designed per Section R703.
How far should flashing go up wall?
8″
Through-wall flashing is used at all points where moisture may enter the wall, and in selected places particularly susceptible to water damage. The flashing must typically rise at least 8″ from the low point at the exterior face of the building to the high point inside the wall.
What is the weakest part of a masonry wall?
In a CMU loadbearing wall, the weakest component is the: mortar.
How far should flashing go under siding?
Remember to provide a 3/8” gap between the flashing and the bottom edge of the siding. Here’s a quick tip: if you are installing LP SmartSide 38 series lap siding, you can use a scrap piece of the siding to create the proper gap (38 series lap siding is 3/8” thick).
What is through wall flashing made of?
Through Wall Flashing Metal The rigidity of materials such as copper and stainless steel make it a strong long lasting installation that is compatible with most sealants.
Are clogged cavities around flashing masonry a problem?
Although there have been good mortar dropping control systems for masonry on the market for many years now, clogged cavities around flashing continue to be problematic on some buildings. One of the common issues is a tight drainage cavity due to the installation of external insulation.
Where do you put flashing on walls for drainage?
The wall system begins with flashing at the bottom of the wall, which collects water that drains down the wall and kicks it out at the base. Metal or PVC flashing can be used. It should have a drip edge that hangs below the sill plate, with the bottom edge at least 8 inches above grade ( EPA 2015 ).
What type of flashing is needed for veneer wall systems?
These flashing types must be cut or held back the wall face, and a drip edge can be used to direct moisture away from the wall face. The drip edge must be made of a material that is not sensitive to UV exposure and won’t corrode. Flashing is required for veneer in cavity wall systems, but it is also required for structural masonry.
Why do flashings need to be terminated within the wall?
When flashings are specified to be terminated within the face of the masonry veneer and not “daylighted” to the exterior, water may flow off of the edge of the flashing and be retained within the wall.