Poor drainage on roofs and balconies impacts balcony waterproofing performance. Our latest blog looks at the effects of runoff, the risks of inefficient roof and balcony drainage, and how to prevent balcony waterproofing failures.
How does water runoff impact balconies?
Roofs are designed to direct water into drain systems to prevent water runoff. When drains are inefficient, water overflows down vertical walls and lands on the horizontal balcony surfaces below. Poorly designed balconies also cause runoff, making matters worse. As a result, roof runoff is not the only cause of balcony waterproofing failure. The combination of water runoff from the roof and balconies below increases the risks of waterproofing failures and damage in the following ways:
Water pooling
Pooling gives water more time to penetrate small cracks and pores, leading to water damage. The pooling also rusts and corrodes the metal balcony railing systems, anchors, and fasteners, loosening the railing and creating a safety hazard.
Freeze-thaw cycles
In colder weather, water trapped in the concrete slab freezes. Frozen water expands, putting pressure on the concrete, expanding existing cracks, and causing new ones. Every time the concrete expands and contracts, the damage worsens, causing delamination and spalling.
Corrosion
Concrete slabs are reinforced with steel bars. Delamination and spalling expose the bars to moisture, causing rust. Rust expands the steel bars, adding further pressure to the concrete. The bars and concrete separate, damaging the balcony’s structural integrity.
Causes of poor balcony and roof drainage
There are two areas that contribute to poor drainage:
#1: Design & installation
Poor design and installation cause pooling, prevent proper drainage, and create entry points for water penetration. Efficient design measures include:
- Sloping directs water away from the building and into drain systems
- Waterproofing systems on balconies provide protection against pooling and prevent water penetration
- Proper seals reduce entry points for water, including joints and seams where balcony components meet
- Flashing seals joints along balcony edges, drain systems, and joints
- The right-size drainage system ensures the drains manage rainfall efficiently to prevent overflow
- Drains installed at the correct height in relation to the balcony or roof ensure full drainage to prevent pooling
#2: Maintenance
Proper maintenance is a must to ensure the system remains efficient. Removing debris from drains will prevent backups that lead to overflows impacting the balconies below. Balcony inspections also identify waterproofing issues early.
Improving balcony waterproofing
Balconies are entire systems with several components working together to ensure structural integrity and building envelope protection. Addressing the system as a whole extends the balcony’s lifespan while improving safety. Here’s how WellDone Inc. improves balcony waterproofing:
Coatings
We use a combination of waterproofing methods, including:
- Liquid-applied membranes to create a seamless seal that fills concrete pores and gaps
- Sheet-based membranes made of bituminous compounds, rubberized asphalts, or polyethylene applied in overlapped sheets
- Polyurethane coatings to reduce cracking and splitting Â
Inspections
Balcony and roof inspections consider how water pools and drains. After watching water activity, we make slope adjustments to direct water off the slab and away from the building envelope.
Railings
We restore rusty railings by removing the concrete, taking out damaged steel components such as baseplates, and replacing the concrete and railing system. We also use crystalline admixtures for concrete slab replacement to help block moisture.
A combination of inspections, maintenance, and restoration allows us to identify failures and design a strategic prevention and restoration plan to restore balcony waterproofing efficiency.
At WellDone Inc., a building restoration company in the GTA specializing in building improvements for commercial and multi-unit residential buildings, we provide thorough exterior inspections to identify exterior vulnerabilities and devise effective exterior maintenance and restoration plans. Reach out to us today.