Application of the Standards and Guidelines to replace the cedar shingle roof on Old St. Stephen’s College

Old St. Stephen’s College, designated a Provincial Historic Resource in 1983, and office of the Historic Places Stewardship Section (the authors of RETROactive), is getting a new roof. The work is compliant with the principles and recommendations outlined in the Standards and Guidelines for the Conservation of Historic Places in Canada. Below is a brief description of the conservation work that will be completed throughout April and May 2012.

The roof over the west wing and its multiple hip-roofed dormers are cited in the Statement of Significance as character-defining. The design for the cedar roof replacement may seem straight-forward at first, but when planning this work it was important to consider not only the look, but how the roof would perform. The introduction of new underlay products and flashings were examined in order to better help keep the water out and extend the service life of the roof.

For any historic place, the Standards and Guidelines for the Conservation of Historic Places in Canada must be consulted for all proposed interventions.  In this case, a cedar shingle finish for roof surfaces, ridge caps and dormer side walls was verified as appropriate with reference to general Standards 1 to 9 and Standards 10 to 12 for rehabilitation treatments (see pages 22 and 23 in your Standards and Guidelines document).  Standard 8, in particular, confirms the replacement “in kind of any extensively deteriorated or missing parts of character-defining elements, where there are surviving prototypes.”

In addition to the replacement of the shingles, the opportunity to introduce new weatherproofing materials was presented.  Particular areas at risk with this roof were identified, which included the six dormers penetrating each side of the peaked roof, along with multiple valley and ridge flashings.  Also complicating the design is the presence of deep gutters with internal drains just behind the brick and cast-stone parapets.  A new continuous ice dam membrane underlay was proposed that would be installed from the parapet through the gutter, to the top of the dormers, lapping the membrane up the dormer sidewalls, and to the underside of window sills.  This has been likened to installing a weatherproof girdle under the shingles, covering most of the roof surface, to help protect the vulnerable complicated intersections from leaks.

The proposed introduction of new underlay material to this roof was confirmed in the Guidelines for Roofs (page 142), where it is recommended to “improve the detailing of roof elements, following recognized conservation methods, to correct faulty details.”  Such improvements, however, should be physically and visually compatible with the authentic roof detailing.

So, all the boxes are checked with regard to the west wing’s roof replacement and the protection of its heritage values.  The Standards and Guidelines for the Conservation of Historic Places in Canada provides a defendable verification that planned work for historic places retains recognized heritage values.

Written by: Tom Ward, Manager of Heritage Conservation Advisory Services