Roof Over Our Heads

The buildings of Shadyside Presbyterian Church represent a wide variety of shapes, sizes and proportions. Each was designed to suit the intended (and foreseen) purposes of the spaces enclosed. Richardsonian Romanesque style readily accommodates functional design with volumes and masses in picturesque compositions. This leads to an equally varied collection of roof types, matching the functions of a roof to the building plan.       These functions include shelter from the elements (rain, snow, sun, wind and temperature extremes), disposal of rain and snow melt, ventilation, admission of light and structural soundness.

Shed Roof Form

Shed Roof on Colonnade at South Porch

Among the simplest roof shapes is a sloped, flat plane known as a shed roof.     Obvious examples of a shed roof are the colonnaded extensions to the church’s two “porches” (the sanctuary’s Westminster entrance and the Craig Room ). These are relatively small roofs, but receive and channel runoff from a number of nearby roofs.

Gable Roof Form

Entrance Gable

The gable is perhaps the most familiar roof shape and, at Shadyside, covers the transepts, the main entrance and the chancel of the sanctuary. Since it is undesirable to direct runoff toward the building or over an entrance, the two sloping sides and flat front are appropriate.

Hip Roof Form

Chapel Hip Roof with Modifications

Next in the development of shapes is the hip roof. It can be thought of as a gable roof in which the vertical triangular wall ends are “tilted back” to form two additional roof planes. While the hip roof has structural and aesthetic advantages, it is useful in limiting the water runoff volume sent in any single direction.

Shadyside Church Chapel

Shadyside’s chapel is covered by a hip roof that has (and had) various embellishments.       First, we notice that the end planes of the hip roof do not rise completely to the main ridge line. Instead, a small triangular panel is formed (known variously as a Dutch gable, gabled hip or gabelet). One source of this feature is the medieval hall building, which often housed people and animals – hence the useful ventilation feature.

The chapel building today has a “loft” level of offices above the parlor, beside the chapel worship space. When completed in 1892, the chapel consisted of a single large bay, which could be subdivided by movable walls. The three dormer windows on each side of the structure would have been an important light source during the day.  In addition, skylights were mounted on the long planes of the hip roof and were later removed. In the loft offices, the side dormers and the one above the front entrance make a very animated ceiling.  (The entrance dormer also deflects water away from the chapel door.)

Pyramid Roof Form- Showing “Sprung Section” at Base

Pyramid Roof on Church’s Lantern

A special case of the hip roof is seen on the church’s signature lantern tower.  The pyramid shape is formed by stretching four equal panels to a point high above the square base. Besides being ta most graceful termination of the tower, this form equalizes the amount of rain runoff in each direction.   Another feature of the lantern roof is functionally related to runoff: at the base the roof slope decreases. This is called a “sprung roof” and it sends the runoff away from the wall surface below (where it could increase erosion). It is also imparts a picturesque, medieval appearance to the composition.

Roof Dormer with “Witch’s Hat”

Perhaps the most complex roof is that of the lantern dormers.  They echo the pyramid shape at the front, transitioning into a gable that joins the main roof.  The bottom is sprung recalling a shape sometimes referred to as a “witches hat.”  While they are certainly charming, the dormers fill a critical purpose of ventilating the space under the pyramid.

Conical Roof Form with Gable Extension

Conical Roof at Pastor’s Study

Related to the pyramid shape, there are two conical roofs at the church. One covers the Pastor’s Study tower and blends with a gable extending to the main building. The other is half-conical in shape and tops the semi-circular apse added to the east end of the sanctuary in 1938.

Flat Roof at Parish Hall

Shadyside Church also has several examples of the so-called “flat roof.” A truly flat roof would retain snowmelt and rain. The associated leakage is a practical problem of such an arrangement. In practice, there are features to channel water away. The first large flat roof at the church was on Parish Hall. As for the authenticity of a flat roof for a Romanesque Revival structure, Shadyside’s Centennial History points out that ample precedent was found in medieval examples.

Skylight View of Lantern at Stair Tower

The lovely Sharp Atrium, constructed during the church’s “Building Community” campaign is also covered by an essentially flat roof. Indeed, the varied surrounding walls and roof lines would have made any other style impractical. Skylights in the Sharp Atrium and the new stair tower leading to Parish Hall are key features of the delightful ambience of these spaces. In this sense they borrow from the original design of the adjacent chapel roof, where skylights once existed.

Sharp Atrium at Night

And so, we have the development sequence:  function determines the plan; the plan is extruded to form useful, attractive volumes;  the projected plan sets base shape of the roof;  practical considerations, tempered by aesthetics, lead to the roof form. The resulting animated roofline, then, speaks of the varied and vital ministries that flow out of the church.

 

About Tim Engleman

I am a semi-retired mechanical engineer with an interest in church architecture.
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