Design professionals are comfortable with dozens of envelope alternatives for buildings with conventional, linear geometry. But such comfort may sometimes bend along with curvature. Free-form surfaces do prompt: "Can you clad that?", "Even with double-curvature?", "Will it fit my budget?". The short answers are likely "triple-yes".
Freedomes and facades may be clad in many different ways to achieve most architectural intents and budgets. This article, the first in a series of four, covers options for external weatherproofing of free-form cladding. Future articles will cover insulation (thermal and acoustic), interior appearance, and, finally, exposed structural patterns.
Exterior cladding options
1.Standing seam roof, or "SSR", is a very popular option for architectural roofing. No deck is necessary as the roof spans between the purlin supports. SSR panels are fabricated on-site and run continuous from the water-break to the roof edge. With no horizontal seams there are no waterproofing worries. SSR is shown alone in the following detail, but of course, it can be used in combination with insulation and ceilings. Example of the outside look of SSR is the Velodrome and the Glory Sanctuary.
2. Individual panels. Panel support system follows the structural grid and provides a triangular or rectangular pattern on the outside of the dome. There are two mutually-reinforcing waterproofing systems working together. First, neighboring panels are sealed one to the next. Second, a redundant, three-way gutter system insures that any condensation or infiltration are captured and removed. Glass and insulated panels may be combined for striking effects. Examples of the external look are the DSWMC Qatar and the Papalote Museum.
3. Deck and membrane waterproofing. Optionally, this can then be finished with architectural metal forming a rainscreen system. Deck can be flat or corrugated. The membrane can be any of a number of products: PVC, bituminous, elastomeric. These can be adhered, fastened or painted on the deck. And, if desired, architectural metal can float above the waterproofing membrane.
The Marchwood dome, the Soumaya Museum and the Sports Palace use variations of this type of cladding.
4.Structural membrane only. Fabric and ETFE can be used to clad domes and façades with striking effect.
The above are only a few of the multiple possibilities for your free-form building envelope. Look out for the next article, where we will cover acoustic and thermal insulation.
When you are ready to discuss your project, please call. Designers and engineers are ready to assist your team in coming up with the right system for your building.