Ancillary Roof System Concerns
Our industry benchmark setting TS324® 3”x 24” trapezoidal rib and the Panel Craft ™216/218 architectural vertical 2” x 16/18” licensed roof systems often time require ancillary roof apparatuses to finish out a project such as roof curbs for Heating Ventilation and Air Conditioning (HVAC), lightning abatement, equipment anchoring utility clamps, pipe penetrations, and light transmitting skylights. BRS has sought to provide answers to some of these frequently asked questions and concerns.
Standing seam roof systems require special attention for through roof penetrations such as vent pipes, signage/equipment screen supports, and especially HVAC roof top units requiring curbs. BRS seeks technology that will last as long as the roof system which the apparatuses are an integral part of the overall performance and longevity of the installed roof.
Roof Curbs
BRS has committed to having the highest performing roof systems in the marketplace through innovation, testing, technological development, and our ongoing pursuit to always be the standing seam benchmarks for the industry. This desire requires us to examine and often time tests ancillary roof apparatuses including the largest roof penetrations which require integrated roof curbs.
The roof curb construction and its installation is very important to the longevity, weathertightness and thermal cycling of the in-place roof system. The curbs can be fixed, floating, insulated or non-insulated depending on the Roof Top Unit (RTU) being installed as part of a project roof.
All roof curb construction should be:
- A minimum of .080 welded aluminum, with diverter aprons on the uphill side.
- Rib to rib design with minimum of 0-9” open area around the curb for unrestricted water flow.
- Under/over curb apron design with proper rib matching corrugated closures on the uphill side and over the rib matching corrugated rib cover/caps on the downhill side.
- Aluminum rib covers that perfectly match the panel rib profile.
- Have adequately designed structural support to handle the RTU weight loads without interfering with the expansion and contraction of the thermal movement capabilities of the roof clips and starter/rake plates. BRS has up to 7” of thermal cycle travel in our perimeter plates and some of our clips offered.
- BRS has only one fully vetted roof curb manufacturer that has passed our static waterhead lab tests. The curb manufacturer offers a written 20-year weathertightness warranty on our licensees’ roof systems. Please contact LM Curbs -Longview, TX at phone 800/284-1412 or website: www.lmcurbs.com for more information regarding sub framing required and appropriate aluminum thickness for the RTU’s being installed.
LM Curb Static Waterhead Testing - BRS Lab
Proper Curb Design
Lightning Abatement
BRS is frequently asked about lightning abatement options on our standing seam metal roof systems which could conduct electrical current if struck.
A few areas of concern for lightning abatement requires the correct usage of materials which are not detrimental to the roof metal substrates (usually Galvalume or G-90 galvanized). Dissimilar metals that are in direct contact, or have moisture run off from the attached devices required for lightning protection will accelerate the degradation of the steel surfaces whether paint or clear acrylic coated bare metal. All the lightning protection components must be constructed of similar metals which do not create galvanic or corrosive reactions such as copper or the ions contained in moisture runoff. Therefore, the components typically need to be of aluminum material including all rods, cabling etc. BRS in aware of a premier lightning protection company- Thompson Lightning Protection, Inc.- Minneapolis, Minn. Phone number 800/777-1230 or website: www.tlpinc.com Please contact them directly for additional information and understanding regarding lightning protection for the next metal roof project .
Utility Clamps
Fastening through a BRS standing seam roofing system is not recommended for attaching apparatuses such walkways, RTU drainage related hardware, signage supports, snow retention fences, maintenance work platforms, etc. Typically, any roof top secured device may create negative impacts on the single membrane of a standing seam roof. However, if such roof top attachments are required, BRS suggests the use of non-penetrative attachment means of securing the apparatuses such as utility rib clamps that are designed to the particular finished seam architecture. There are several manufacturers of these clamps in the marketplace which should be contacted for their expertise. BRS would suggest that the panel manufacturer be contacted to assure proper finish seam fit and satisfactory in place results are achieved PRIOR to any installation or purchase of the clamps.
Pipe Penetrations
Roof penetrations on every standing seam requires special attention to prevent negative impacting the roof system performance. HVAC, plumbing vents, structural support pipe features should be handled with a rubber boot with a flexible aluminum base ring secured over non-skinning butyl sealant between base and metal roof secured with long life fasteners per manufacturers requirements. In ice and snow country, an additional snow diverter should be considered on the uphill side of the penetration boot to limit any damage due to avalanching downslope. Please contact the roof flexible boot manufacturer for additional design assistance prior to specifying or approving the supplier.
Skylights
The BRS roof systems have worked in combination with G-5 Enterprises ,Inc to develop a mechanically seamed in insulated, non-insulated and OSHA guideline compliant skylights to allow the energy saving natural light into projects with our roof systems. These Light Transmitting Panels (LTP) feature dual prism technology that allows light transmission of up to 90% for clear and 60% for frost color light distribution. The patented technology of the Sky-Brite Guard protective light transmission panel integrated design provides unprecedented safety preventing fall through According to OSHA Guideline 29 CFR1910.23 (e) (8).
To gain additional information on these amazing seamed in skylight/LTPs please contact G-5 Enterprises Inc -Oakhurst, TX 936/377-3611 or visit: www.sky-brite.com
