November 2016

2016 Metal Construction Hall of Fame
Inaugural Founders Class

Installing Rainscreen Assemblies Building it Virtually
Museum, Library and Cultural Center Projects

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Learn about Out-of-Plane Substrates	By Jeff Haddock	
Out-of-plane substrates can cause problems to roofs

Out-of-plane  roof  substrates  can  create	signed to be installed on a relatively even plane.		ASTM E 1514, Standard Speciﬁcations for real  issues  when  installing standing seam		An out-of-plane substrate could cause binding	Structural Standing Seam Steel Roof Panel, Article roof panels, so the transition from one	points at the clip locations located on the affected	5.2.1 STATES IN PART, "$EmECTION AND SERVICEABILITY trade to the other is critical.	areas. This can create an unwanted point of ﬁxity and	SHALL BE ACCOUNTED FOR. 4HE DEmECTION SHALL BE LIM-
When a metal roof has been chosen for a proj-	could prohibit the panel from expanding and con-	ited so as to allow the roof to perform as designed. ect, it is clear the building owner and architect are	tracting at any affected areas of the roof. Expansion	4HE SUBSTRATE DEmECTION SHALL NOT CAUSE STRAINS TO considering the long-term investment of a building.	and contraction should not be impeded and will still	the panels that affect serviceability of the system." The performance of a metal roof is unmatched, and	take place, even if the clips are bound or pinned at		The transfer of ownership clauses in project the aesthetics of a metal roof functions as an archi-	affected areas of the roof substrate. The strength of	contracts are becoming a huge factor, in recent tectural feature. That stated, an uneven substrate,	the thermal movement in the standing seam panels	times, with regard to out-of-plane substrates.
also referred to as out-of-plane substrate, will cause	could result in clip failure or complete panel disen-
problems to both the performance and aesthetics of	gagement from the substrate altogether if the shear	Solution
the roof. Metal rooﬁng material is typically supplied	resistance of the clip fasteners is compromised.	When the roofer/sheet metal subcontractor takes in light-gauge steel, 29-gauge, 22-gauge, which will		over the substrate and commences its scope
not hide defects in the substrate.	Performance	of rooﬁng work, typically there is an inspection There are three fundamental areas affected by	The last concern deals with wind uplift perfor-	by a qualiﬁed representative. The subcontractor
an out-of-plane roof substrate.	mance. If standing seam roof panels are installed on	representative should be authorized to accept the
an out-of-plane roof substrate, there is the potential	substrate or reject questionable areas that may
Aesthetics	for improper panel-and-clip engagement at the side	need reworking by the appropriate previously The ﬁrst issue with an out-of-plane substrate	laps. If the male/female panel leg is not engaged	responsible trade.
deals with aesthetics. Any unevenness in the roof	properly, the wind uplift values for the panels can		If subcontractors do not do this and start substrate will telegraph through the  steel rooﬁng	be impacted. This has the potential to create serious	installing material, they are essentially accept- panels causing a very unpleasing look. This can	problems with a standing seam roof panel’s ability	ing whatever conditions they are given with no accentuate oil canning and give an undulating ap-	to resist wind uplift pressure. Improper panel side	recourse. Additional labor cost can be incurred to pearance to the metal roof.	lap engagement can also affect air and water inﬁltra-	correct other trades’ installation issues. Inconsis-
tion which can compromise the weathertightness	tent joints, seams, and framing will always transfer
Thermal  Movement	capabilities of the roof system as well.	through to the rooﬁng material and create issues The next concern is the potential that the uneven		Industry standards have established that roof	which the installer becomes responsible for at the substrate could interfere with the panel’s  ability to	substrates should not exceed the  following limits	installer’s expense.
effectively expand and contract under thermal load.	for out-of-plane conditions:
This is particularly an issue with standing seam	s 1/4-INCH IN 20 FEET	Jeff Haddock is technical representative at rooﬁng material, which utilizes concealed clips for	s 1/2-INCH ACROSS BUILDING ELEVATION	AEP Span, Fontana, Calif. To learn more, go to attachment. Standing seam panel clips are de-	s 1/8-INCH IN 5 FEET	www.aep-span.com.

If standing seam roof panels are installed on an out-of-plane roof substrate, there	Any unevenness in the roof substrate will cause a very unpleasing look.  is the potential for improper panel-and-clip engagement at the side laps.	

38	METAL CONSTRUCTION NEWS	November 2016	www.metalconstructionnews.com