Pleated    Structures


Pleated structures also lends themselves to inflation - as illustrated in the following diagrams:

Simple inflation of two membranes

Inflation helps create a curved surface - which is desirable from the point of view of creating a maximally-stable structure.

Inflated surfaces look quite a lot like pleated surfaces - and inflation on its own solves some of the same problems pleating does.

For example, the lack of horizontal surfaces helps prevent pooling in both patterns.

However pleating still offers advantages to buildings with inflated skins.

Inflation of bladders between two membranes

Relatively small bladders would still create an air gap

The main idea of using bladders is to divorce structural components that need to resist the wind and rain from the elements that should be airtight.

The external membrane offers protection to the bladder, prevents punctures - and helps make modular replacements cost-effective.


An alternative to inflation is a multi-layer structure.

Assuming that regular strut support for the cables is being used, there are two main patterns for these:

Ridge to ridge, valley to valley

This structure is of uniform thickness - but the upper struts bear down on the lower cables and struts through the fabric - and there's no terribly neat way of attaching them.

Ridge to ridge, valley to valley

Here no forces are applied by the struts through the fabric - but the cavity is not of uniform thickness - and the upper struts bear down on the lower valley cable, increasing the strain that exerts on the fabric in a manner that may be undesirable.

In either case, it may be desirable to dehumidify the region between the layers - in order to minimise condensation problems there.


If two membranes are used there are possibilities for filling the cavity between them with something other than air.

One possiblity is solidifying structural foam. This creates an opaque, strong insulating barrier.

Another possibility is to use the pleated membranes as a mould for concrete.

Having the structural role in pleated structures played by cables allows them to carry considerable weight.

Letting each layer of concrete set before applying the next reduces the need for the cables and membrane to support the weight - since the set concrete is self supporting.

It looks as though dual cable-supported pleated membranes may well come to present an attractive alternative to existing concrete mould technologies in some cases.

After construction, the membrane and cables would be removed.

Tim Tyler | Contact |