Construction of a flat roof is a labor-intensive process requiring special equipment and expertise.

Construction of a flat roof by the roofing professionals at Avenue Road Roofing is a multi-step process that includes preparation of the job site, vapor retarder, insulation, a membrane system, roof drains, sheet metal work, caulking and sealing, complete clean-up – and a long list of project details you probably never even imagined.

Safety is also a key consideration, not just for the roofers, but also for pedestrians.

If you get anything less, you could end up with a flat roof that will have a shortened service life or, worse still, a failure that could put your employees, building contents and daily production at risk.

Step #1 - Preparation Work

• Strip off existing roofing materials and associated metal work
• Dispose waste materials in a legally approved manner at an approved recycling or dump facility
• Prepare deck surface by:
  • replace any rotted boards or sheeting ( wood decks)
  • inspect, paint or replace corroded panels (metal decks)
  • inspect, re-surface (concrete decks)
  • inspect, repair /replace any supporting rafters

Step #2 - Vapor Retarder

• Wood decks (#15 lbs. felt)
• Metal decks (craft paper /adhesive)
• Concrete decks (asphalt coating)

Step #3 – Insulation

• Insulation systems are installed over the vapor retarder and are secured using mechanical fasteners and/or hot asphalt depending on the application
• Insulation thickness can influence the quoted price. On some applications; the installation of fire retardant sheetrock is required over metal decks
• Fibreboard ( basic four-ply built up system)
• Polyisocyanurate (thermal insulation, 1” to 4” options having incremental R values)
• Asphalt saturated proteco-board (for torch applied roofing system)
• Rigid Styrofoam (for application on inverted /PMR roof systems)
• Tapered insulation (factory designed to provide positive drainage)

Membrane Systems

• Four-ply organic felt, applied with full coatings of hot asphalt, four plies of felt flashings at walls, upstands & strategic target areas
• Final application of pea gravel, embedded in hot asphalt pour (typically referred to as BUR or built up roof)
• BUR (built up roof system) as described above, but with substitution of inorganic glass felts
• Modified bitumen systems. Torch applied consists of smooth surfaced base sheet and ceramic granular cap sheet, both fully adhered and forming a two-ply system. Variations include base sheet applied with hot asphalt and cap sheet torched and both plies being applied in hot asphalt. Cold asphalt applied systems are available.
• PVC (poly vinyl chloride): applied with adhesive and hot-air welded at overlapping seams
• Inverted Systems (PMR’s-protected membrane system) can employ any of the membranes described above. However, the water-proofing membrane is applied to the deck and the insulation layer is on top, covered in a filter cloth and pavers or large river-wash aggregate. This system is often used in high rise or high traffic roof situations.

Roof Drains

• Through wall or through canted edge scupper drains are usually attached to down pipes
• Interior roof drains come in various throat openings, ranging from 1” to 4” diameters, and connect to interior drainage pipes. Drains are typically constructed of cast iron or copper.
• Interior drains should employ u-flow seals (which help prevent backup) and debris guards to help prevent clogging. Gutter systems, including down pipes, are used on open flat roof edges or perimeters.

Sheet Metal Work

• 	No job is beyond the skill of the craftsmen who work in Avenue Road Roofing’s in-house metal works shop.

  Required at vulnerable areas of the roof
• Designed to protect membrane flashings at strategic areas, such as walls, canted edges, skylight or roof hatch curbs, parapet wall caps
• Sheet metal work should be constructed of 26 gauge, pre-painted galvanized steel or copper (copper is more expensive, but is corrosion resistant and a better match with traditional architecture)
• All Avenue Road Roofing metal work is custom made off-site in our metal shop facility
• Installed on-site by our trained metal mechanics
• Metal should be fabricated using S or (slip) locks, which allow for expansion and contraction
• Corner joints should be lock-seamed & mitered. Variations can involve standing seams and soldering or braising of materials

Caulking & Sealing

• Applied to all key areas, such as wall flashings, pitch cones and pockets, metal to masonry, metal to glass, skylights
• Specific sealants should be used for specific applications
• Sealant should be applied in a uniform bead and tooled to a proper finish
• Some applications require specialized sealants, such as dymeric caulk, diomonic caulk, mastic hydro-shield, silicone, cold pitch and fibrated roofing cement

Variable Project Details

• Replacement of skylight units or roof hatches
• Modification of entry doors or window systems located near roof grade (which can impact roof drainage design, cause potential leak sources)
• Use of a crane to lift and hold large HVAC units, mechanical units
• Disconnect & reconnect gas lines, hydro wires, satellite systems
• Welding of attached fire escapes or large billboard supports
• Paver systems to permit roof traffic
• Wood decks
• Difficult /poor access, or high traffic streets and pedestrian walkways
• Siding or cladding requiring cutting or replacement to accommodate proper membrane installation at wall to roof junctions
• Masonry / brick repairs to parapet walls
• Roof gardens
• Sign cabinets and accessory lighting
• Special working schedules
• Specification work
• Interior plumbing /drain pipe retro-fits and modifications

Complete – and legal – clean-up

• Ensure your contract stipulates complete (and legal) clean-up and shipment of all debris to an approved disposal site. One way disreputable roofers cut their prices is by illegally dumping roofing waste. If they are caught (it does happen), it’s the roofer and business owner who get charged.

Project Safety

• Provide necessary hoarding and protection barriers for pedestrian traffic
• Provide traffic and pedestrian control, if necessary
• Erect scaffolding, if necessary, for worker and public safety
• Provide temporary fencing to surround tar kettles and isolate propane storage
• All workers equipped with approved safety equipment, hard hats, fall-arrest equipment, safety boots and eye protection
• Erect guard rails
• Use heat detectors and provide a safety watch after completion of each day’s operations