T&S Roofing Systems – Understanding Section 1524 (part 2 of 2) Roofing Miami & Fort Lauderdale

In part two of Understanding Section 1524 blog, we will discuss the clauses pertaining to ponding water, overflow scuppers, and ventilation. As explained in the previous edition of Understanding Section 1524 blog, this section governs the minimum requirements and standards of the industry for roofing installations in Miami and Fort Lauderdale. Section 1524, as part of Chapter 15, outlines the “exclusions” not covered by the building code for roofing in Miami and roofing in Fort Lauderdale.

Number 5 of 7 on Section 1524, Ponding Water, is an issue that homeowners and contractors struggle with often. The rule of thumb when determining if a flat roof system has positive drainage or has a ponding water problem is if water remains on the roof 48 hours after it rains. If the ponding water does not evaporate within this period, then the roof system may be at risk of premature deterioration. The most common and only guaranteed method of preventing ponding water is to install a tapered insulation system. Tapered insulation systems in roofing Miami and Fort Lauderdale consists of installing a rigid board insulation designed by a tapered department at material suppliers that provide a slope to the flat roof of ¼” or 1/8” per foot. The tapered department will design a system that diverts water to the eaves of the roof, wall scuppers, or roof drains. The problem with tapered insulation is the cost which can often be over 50% of the cost to replace the roof. Other methods of correcting ponding areas include building up the low laying area with additional layers of roofing material (interlayers) or removing the decking and reinforcing trusses that may have sagged due to aging or roof leaks. However, these two methods do not provide the guarantee that a tapered system offers.

The next item on the Section 1524 pertains to overflow scuppers. It explains that overflow scuppers are wall outlets that allow rainwater to flow off of the roof when the flat roof is surrounded by walls, also called parapet walls. The quantity of overflow scuppers, their locations, and sizes are determined by a roof engineer which performs calculations depending on the dimensions of the roof, location of the building, and average yearly rainfall of the building’s geography. This is especially the case in roofing miami and roofing in fort lauderdale.

The last item on the Section 1524 is Ventilation. Ventilation is an issue that will be further discussed on a future edition of this blog, but the Section 1524 page simply states that “most roof structures should have some ability to vent natural airflow through the interior of the structural assembly”. It also states that the existing amount of ventilation should not be reduced when replacing the roof. The amount of ventilation required in roofing miami and fort lauderdale is usually project specific and is determined by the area of attic space, existing soffit vents under the overhangs, and existing insulation. The National Roofing Contractors Association does not specify the best practices for roof ventilation and states that “homeowners should consult manufacturers for specific ventilation requirements..”. The Federal Housing Administration recommends a minumum of at least 1 square foot of attic ventilation for every 300 square feet of attic space. This rule of thumb is also support by GAF, the largest roofing manufacturer in the US.