Civil Engineering Reference
In-Depth Information
Chapter 3
STRAWBALE BUILDING TECHNIQUES
EXPLAINED
Loadbearing (also called
Nebraska)
attached to the ring beam before building
up the straw walls again beneath the roof.
The wallplate, or roofplate (a continuous
perimeter plate that sits on top of the walls
at each floor level and under the roof)
is fastened to the bales with coppiced
hazel and may be strapped down to the
foundations, depending on local weather
conditions and the weight of the roof. The
roof is constructed on top of the roofplate,
following strawbale design principles.
This is the original way of building with
straw bales, pioneered by Nebraskan
settlers in the USA in the late 1800s. At
amazonails, we prefer this method above all
others for building any type of construction,
small or large, because of its simplicity, flex-
ibility of design, enhanced thermal perform-
ance and cost-effectiveness.The potential for
empowerment through working together on a
shared project is one of the great advantages
of this type of building, as it is such an acces-
sible building method: pretty much anyone
can do it, and it's a lot of fun!
Windows and doors can be installed in vari-
ous different ways. The simplest method is
to place them inside structural box frames,
which are built into the bales as the walls
go up. This approach is usually used for
small-scale and community buildings and
self-build experiments. It may require more
timber than other methods, but it keeps the
actual bale building aspect to its simplest.
It requires little previous knowledge of wall
construction and is very accessible.
In the loadbearing technique the bales,
which are structural blocks, are designed to
take the weight of the roof; there is no need
for any other structural framework. They are
placed together like giant bricks, pinned to
the baseplate (a continuous timber plate,
usually a flat ladder structure, that sits on
top of continuous-type foundations) and
to each other with coppiced hazel, and
a continuous rigid timber ring beam on
top spreads the floor and/or roof loads
across the width of the wall. For two-storey
houses, the floor joists at first-floor level are
An alternative way of installing windows
and doors, and one used predominantly on
mainstream building sites, is to use doubled-
up 100mm x 50mm (4” x 2”) uprights either
side of the opening, fastened securely to the
baseplate and projecting through slots in
the roofplate. These are housed fully into the
