Flood Remediation
Frequently Asked Questions
Doing the Retrofit
Consult the detail drawings (Option 1: Rainscreen Retrofit, Option 2: Retrofit Brick Ties and Rainscreen) and videos. Always consult with building codes officials before beginning any construction project.
- Treat the stud cavity for mold and allow to completely dry.
- Preserve any flashings that are present and clean out weep holes. If weeps aren’t present drill them through mortar joints at the lowest point in the wall to drain water from the rainscreen. Leave brick ties in place, and reinforce with expanding spray foam. If brick ties are missing, install MTI Retrofit Brick Tie™.
- Create a rainscreen drainage and ventilation gap on the interior with the Sure Cavity™ rainscreen drainage plane. Install with fabric facing the installer, back-wrapped at the bottom to create a bugscreen, and shingle-lap fabric in subsequent courses. The Sure Cavity can be attached to the studs or wedged in place against the brick wall.
- Apply 2 inches of 2-pound density closed-cell spray foam insulation between the studs and over the Sure Cavity. Apply a preventative fungicide to the spray foam and stud cavity.
In a future flood these drainable, dryable, water-tolerant materials can remain in-place – just wash down and replace the flooded interior drywall. For next steps on rebuilding a flood-resilient interior finish view the wet-floodproofing recommendations below.
FAQs – Frequently Asked Questions
Flooded exterior sheathing & insulation should be removed to above the flood line. Use light-guage sheet metal to create a flashing from the between the upper sheathing and studs to the brick wall. Install the Sure Cavity to overlap the flashing.
Using the rainscreen retrofit technique along with “wet floodproofing” approach for your interior renovation will result in a wall system that is drainable and dryable. Using flood hardy materials reduces the time and resources required to rebuild after a flood.
Wet Floodproofing Resources
No. Unless your home is a submarine the exterior materials along with doors and windows are not watertight and will succumb to the flood waters. Standing water in contact with brick walls (or other veneers) will inevitably enter the structure and plugging weep holes will not improve the situation.
Consider using insulation that is water tolerant, such as closed-cell insulation in spray foam or rigid foam panels. Closed-cell insulation will not absorb water and may not require removal in a future flooding event. Closed cell spray foam also adds racking resistance to the wall.
Not in residential construction. Let’s look at two categories of brick walls: brick veneers and load-bearing brick walls. Load-bearing walls have multiple wythes (thicknesses) of brick and are common in historic institutional buildings. Brick veneers have a single thickness of brick and are common on residential buildings. Applying spray foam to the interior of load-bearing brick walls is common because the multiple wythes of brick can store and redistribute the moisture. In a residential brick veneer, the single thickness of brick is not able to store and redistribute the moisture – it needs a drainage gap on the backside. Spray foam applied directly to the brick veneer leads to premature wear and damage to the brick and mortar.
Many homes lack base flashing, but they can still use the rainscreen approach. In this case, the best approach is to use a fluid-applied flashing on the bottom plate, slab, and brick ledge.
Regardless of your repair approach, any home with wood-based construction needs to be on alert for possible termite intrusion. Though weep holes seem like an obvious area of concern, termites can squeeze through very small cracks, such as those in mortar joints or brick vents. Maintain as much distance between the soil and weep holes as possible and use chemical pest control as necessary. Constant vigilance against termites is required.