Vault roof / vault cover The physical overhead structure, including concrete slabs, steel support beams, and waterproofing, that caps a sidewalk vault and forms the public walkway.
The vault cover must be engineered to handle heavy foot traffic and accidental vehicular wheel loads while keeping the basement space completely dry below. It typically consists of a structural concrete slab reinforced with steel beams, a high-performance waterproofing membrane, and a four-inch concrete wearing surface on top. Property owners must ensure the exterior finish remains slip-resistant and completely flush with the surrounding public pavement to avoid trip hazards. Because water leaks can slowly corrode the hidden steel beams supporting the roof, maintaining a pristine, crack-free concrete surface is critical for long-term safety.
Frequently Asked Questions About Vault roof / vault cover
What is a vault roof or cover?
The structure that caps a sidewalk vault and forms the public walkway, typically a reinforced concrete slab on steel beams with waterproofing and a wearing surface.
What loads must it carry?
Heavy pedestrian traffic and incidental vehicle wheel loads, per the structural rating required by the Building Code.
Why is waterproofing so important?
Water passing through cracks corrodes the hidden steel beams supporting the roof, which is how these structures fail.
What surface condition is required?
Slip-resistant and flush with the surrounding sidewalk, with no lips or level changes that create trip hazards.
Are cracks on a vault cover serious?
More so than on ordinary sidewalk, because they admit water to the structure below. They warrant prompt professional evaluation.