Flat Roofing Systems
Flat roofs are a waterproof roofing system unlike sloped roofs which require water to shed. There are a great variety of roof systems available to suit the needs of the structures being protected. Chateau Roofing & Siding primarily offers three types of flat roofing systems for our market.
Tear off existing roof
Ideally, removing the existing roof will allow us to expose the roof substrate whether it be wood sheathing, concrete, or steel decking. With roof deck exposed, it can be examined where rot or a structural issue can be addressed. To save on cost, components of the roof system can be reused, like insulation and vapour barrier, having the old membrane removed and those remaining components prepared for a new membrane layer. This process is often called "skinning". This may leave any underlying issue as unnoticed and therefore unaddressed.
Vapour barrier (required for insulated roof systems)
Vapour barrier is only required in roof systems using insulation, because it retards the migration of water vapour into a roof system. It should be continuous with any other existing vapour retarder in the building to best maintain the integrity of the building envelope. Easily done in new construction. A little more difficult in older buildings when building codes were not as they are now. The type of vapour barrier need will depend on the type of roof deck. Self adhered must be used directly to wood. A torch applied vapour barrier will require a protection board like gypsum board or other fire-rated protection board unless the roof deck is concrete.
As previously stated in the vapour barrier section, the building envelop must be considered when trying to increase the energy efficiency of the building. Other things must be considered too. The amount of existing insulation and drainage, desired thermal resistance (R-value), and type of insulation. If there is existing insulation in the roof system, the roof thickness will need to be matched depending on drainage. Any drainage issue can be addressed using a sloped insulation package. The building's energy efficiency can be addressed at this time. Manitoba Hydro has a rebate program where you can pre-apply to get rebate for improving thermal resistance; R-28 for residential and R-25 for commercial. The type of insulation will depend on the application of the roof system and budget.