纽约圣约翰神明大教堂穹顶修复丨美国曼哈顿丨Ennead Architects

历史三年时间，国际知名建筑事务所Ennead Architects完成了纽约圣约翰神明大教堂中心穹顶的修复工作。这座位于曼哈顿晨边高地（Morningside Heights）的地标曾经受到长期的退化和渗水问题，更在2001年因火灾而遭到毁坏。Ennead为教堂重新设计了一个铜质的圆顶，为历史悠久的旧穹顶提供了永久性的防水和隔热性能，并改善了结构的完整性。

Internationally renowned architecture firm Ennead Architects completed its three-year preservation of the Crossing Dome at the heart of the Cathedral Church of St. John the Divine in New York City. Located in Morningside Heights in Manhattan, the landmark Cathedral has suffered years of deterioration, water infiltration and damage from a 2001 fire. Ennead designed a copper roof that provides the historic dome with permanent water-proofing, thermal insulation and improved structural integrity.

▼项目鸟瞰，Aerial view

▼大教堂主立面，Main facade

大教堂的圆顶最初是由美籍西班牙建筑大师Rafael Guastavino在1909年设计和建造，它由重叠的、自承重的赤土陶瓦构成，在当时作为临时结构使用。该圆顶的直径接近133英尺（约40.5米），横跨了大教堂的四个花岗岩拱门，并界定了教堂的十字翼交叉处。后续的几次设计旨在用不同大小的塔楼或尖顶来补完这一交叉空间，其中包括一些拆除临时圆顶的方案。1916年，在建成仅7年后，这座规模宏大的圆顶（是同类建筑中最大的）被逐步夷平，并相继实施了多次修缮工作。

Originally designed and constructed in 1909 by famed Spanish-American architect and master builder, Rafael Guastavino, the Cathedral’s dome is made of overlapping, self-supporting terra cotta tiles and was intended to be temporary. It is nearly 133 feet in diameter and spans across the Cathedral’s four great granite arches which define the Crossing. Subsequent designs called for completing the Crossing with towers or spires of various sizes, some of which presumed the removal of the ostensibly temporary tile dome. In 1916, just seven years after its construction, the ambitiously-scaled dome (the largest of its kind) had already begun to flatten, and the first of many repairs were performed.

▼场地环境，Context

▼圆顶近景，Close-up view

▼新建造的圆顶界定了教堂的十字翼交叉处，The dome spans across the Cathedral’s four great granite arches which define the Crossing

在前期修缮中，只能够短期维持的屋顶薄膜导致了大量的雨水渗入，这也为提出一个更持久的解决方案提供了动力。Ennead的设计采用了一种可以长久维持的、木楞式接缝的铜屋顶，与相邻的原始铜质屋面保持了相同的设计语言，并且能够为穹顶提供隔热和永久性的防水。

The failings of successive short-term roofing membranes led to extensive rainwater infiltration to the dome itself and the arches that it sits on and was the impetus for the construction of a more durable solution. Ennead’s design utilizes a longer-term, batten-seam copper roof that fits in with the language of the adjacent historic copper roofs to provide the dome with thermal insulation and permanent waterproofing.

▼穹顶的铜质表面与旁边唱诗班空间和半圆形后殿既有的铜顶相匹配，The copper for the dome matches the existing copper on the Cathedral’s adjacent choir and apse

为了解决雨水渗透问题，Ennead首先拆除了已经被浸透的旧隔热材料，并在维修之前让砖瓦充分干燥。之后，事务所与顾问团队（包括Silman, Building Conservation Associates, Inc., 和James R. Gainfort AIA Consulting Architects PC）对原先的Guastavino砖瓦进行了细致的评估，并将已经松动、破裂和浸水的砖瓦替换为Sandkuhl Clay Works专门为该项目定制的新铜瓦。

To address water infiltration, Ennead first removed the old sodden insulation, and allowed the tiles time to dry before repairs were made. Ennead and its consultant team, including Silman, Building Conservation Associates, Inc., and James R. Gainfort AIA Consulting Architects PC, then carefully assessed the conditions of the original Guastavino tiles, replacing loose, cracked and water-damaged tiles with new customized tiles for the Cathedral by Sandkuhl Clay Works.

▼近观穹顶，Close-up view

穹顶铜瓦的表面使用了喷涂泡沫保温材料，减少了日常和季节性温度波动导致的膨胀和收缩。穹顶的铜质表面与旁边唱诗班空间和半圆形后殿既有的铜顶相匹配，并将在未来的几十年间逐渐变为青绿色，从而与教堂建立最初便存在的天使Gabriel的雕像变得更加相衬。若保持适宜的维护，这座新圆顶可以再持续使用100年之久。

The expansion and contraction of the dome due to daily and seasonal swings in temperature was reduced by the application of spray foam insulation to the surface of the tile dome. The copper for the dome matches the existing copper on the Cathedral’s adjacent choir and apse and will patina to a verdigris green over the next few decades, eventually matching the statue of the angel Gabriel that has stood on the apse roof since the early phases of the Cathedral’s construction. With proper maintenance it could last another 100 years.

▼眺望天使Gabriel的雕像，View towards the statue of the angel Gabriel

▼雕像近景，Close-up view to the statue

▼夕阳下的大教堂，The cathedral in the sunset