Austin Hall, Sam Houston State University, Huntsville, Texas
Retrofit Team
- ROOFING CONTRACTOR: Empire Roofing, Austin, Texas
- BUILDING ENVELOPE CONSULTANT: Armko Industries Inc., Austin
MATERIALS
Armko Industries was contracted to determine the best plan of action for resolving issues with and restoring the Austin Hall roof, internal gutters and cupola to a watertight condition. Empire Roofing and Armko Industries put together a plan that required the removal of the stainless-steel flat-seamed panels and the internal gutter liner. The Texas Historical Commission was involved in the renovation to ensure the new roof would be as historically accurate as possible. Armko Industries specified removal of the existing stainless steel (installed in 2009-10) and reroofing with McElroy Metal’s 20-ounce copper 238T standing-seam roofing system on all roof sections, as well as adding interior gutters and related sheet-metal components.
Specifications called for siding to be removed at the cupola walls and a new liquid-applied waterproofing membrane applied over the new sheathing with new siding installed to match the original siding. At the base of the cupola, the specifications and details called for the installation of through-wall flashing, using 20-ounce copper. Titanium PSU-30 high-temp self- adhering underlayment covered the roofing substrate and was used as a lining in the internal gutters, under the 20-ounce copper.
“We set up scaffolding and worked on the octagonal cupola first,” explains Aaron Todd, who leads Empire Roofing’s metal roofing and sheet metal division. “The design incorporates a convex curvature with all roof sections meeting at the apex. We measured everything we needed for the cupola roof and gave the cut list to our shop fabricators, who produced the panels and trim for the cupola roofing, the design of which was proposed by Empire and approved by the Texas Historical Commission and Armko. We also had a 10-foot mechanical brake onsite to fabricate and modify any panels as needed during the installation process.”
Todd says standing seams were incorporated at each hip of the cupola to avoid the need to solder vertical joints. At the apex of the cupola, standing seams were folded down and lapped under the finial skirt. The crew sealed/riveted/soldered the finial base to the copper panels to create a watertight and wind-resistant detail at this very exposed and relatively flat area.
Symmetrical standing-seam systems do not have male and female legs but are comprised of panels with matching left and right legs. The panels are joined with a mechanically seamed cap. The panels are non-directional. The seam design on a symmetrical panel is more watertight than a double lock because there is no interruption of sealant in the seam at the clip locations. A symmetrical panel can be replaced if there is ever damage or a reason to pull a panel out of the roof at a later date.
To ensure the internal gutters didn’t cause problems, the Empire Roofing crew used sandpaper to etch the flat 20-ounce copper before it was fabricated into gutters. Once fabricated and roof-loaded, the gutter pieces were joined in 40- to 50-foot sections in the interior gutter, then lifted out and placed on sawhorses. All joints and seams were fully soldered on the sawhorses and then placed in their respective areas inside the internal gutter troughs where the few remaining seams were joined and soldered. The gutters then were coated with Kemper 2K PUR, a solvent-free, fleece-reinforced and liquid-applied waterproofing system based in polyurethane resin. The roofing project was completed in February 2019.
- COPPER PANEL SUPPLIER: McElroy Metal
- GUTTER WATERPROOFING MANUFACTURER: Kemper System
- UNDERLAYMENT MANUFACTURER: InterWrap
THE RETROFIT
Historic Austin Hall is the oldest building west of the Mississippi River to have been used continuously by an educational institution. It was first occupied in October 1851 and completed the following year.
PHOTO: McElroy Metal