Perhaps the least visible portion of a building - the roof - can account for up to 50% of a building's total surface area and can represent up to 25% of the total value of the structure.
By proactively investing resources in properly constructing (and maintaining) a solid roof, you can extend the life of a 15-25 year roof system by heading off leaks and other adverse conditions, which translates into significant long-term cost savings. Preventive investment in the life of your roof happens not just through maintenance, but during the construction process of a new building.
Like any area of construction, the roof requires unique expertise to maximize its effectiveness. Having an expert involved during your building's design all the way through construction can ensure the roof is designed, engineered, fabricated, and assembled to provide watertight protection.
The best time to get a roof expert involved in the construction of a building is during the design phase, while the architects are still working on its detailed plans. A pre-design meeting between the owner/developer, the architect and a roofing expert can help identify any issues architects need to address - especially issues that may be unique to a particular climate.
For example, an architect designing a building in southern Florida needs to plan for stronger attachment of all roof components due to calculated uplift pressure requirements outlined in hurricane-related building codes. In northern climates, considerations must be made for snow weight and removal, ice dams, and the expansion and contraction associated with building materials in extreme climates.
As the design of the building and associated roof system progresses, the roof consultant should review architectural drawings and specifications related to waterproofing and roofing. The goal here not only to ensure that the architectural team designs and specifies a roofing system that will adequately protect the building, but also to ensure that the drawings and specifications are detailed and accurate enough for the general contractor to obtain accurate bids from roofing sub-contractors. Accurate and detailed drawings at this stage can prevent the necessity of time-consuming architectural drawing changes and costly rebids or bid-change orders later in the building process.
The roof expert will be looking at the design drawings and specifications for items such as membrane components & flashing, detailed method of attachment, product compatibility, sequencing of installation, and overall layout
One common mistake is specification of the wrong type of fasteners. For example, projects in coastal Florida may propose using galvanized screws to secure flashing; however, the salt air will rust galvanized screws so a roofing consultant would call out his or her recommendation to use stainless steel. It's a very small detail, but one that can have tremendous impact on the life of a roof and the necessity of future repairs.
After a roofing contractor has been selected, full specifications for the system and all the components he/she intends to use must be submitted. The roof consultant should review these submittals to ensure that they coincide with the original specifications, and to be sure all details are appropriate for the system and the climate.
Many of the various subcontractors involved in a building project will require roof access at some point to complete their portions of the building. Many may actually need to penetrate the roof to install pipes, vents, conduits, or machinery. To coordinate these efforts and ensure that they don't cause damage to the roof, a pre-installation conference should be a top priority. At this meeting, the roof consultant will sit down with the architect, general contractor, roof manufacturer, and any subcontractors whose work may impact the roof to coordinate schedules and plans. This conference can also help determine where extra roof protection pads may be needed.
Quality Assurance Inspections
After all plans, submittals, and products are approved and the actual work begins, quality-assurance inspections should be conducted at various points throughout the installation. The number of inspections varies from as few as 2 to as many as 8-12, depending on the project (4 is a good guideline: 1 at the beginning to be sure everything is off to a good start, 1 in the middle as a progress check, 1 toward the end, and a punch-list inspection at the very end).Common problems encountered in these inspections include everything from waterproofing seam failures to damaged flashing and debris left on the roof. The ultimate goal is a secure building envelope and a watertight roof that is in accordance with required codes and specifications.