This document discusses straw bale construction. It describes how straw bales are used as structural elements and insulation in buildings. Straw bale construction has been used since ancient times, but was revived in the 1990s. There are two common types of straw bales used - those bound with two strings and those bound with three strings. The document outlines the basic steps to construct a straw bale house, including preparing the foundation, erecting a frame, building the straw bale walls, and plastering. It also discusses common materials, advantages like insulation and cost effectiveness, disadvantages like moisture issues, and precautions needed during construction.

1. STRAW BALE
CONSTRUCTION
Presented by
B.Sireesha
15761A0106

2.  Straw bale constructions is a building method
that uses bales of straw (commonly wheat,
rice, rye and oats straw) as structural
elements, building insulation, or both.
 This method is commonly used in natural
building or “Brown “construction projects.
straw bale construction

3.  Straw houses have been built on the African plains since
the Paleolithic era.
 Straw bales were used in construction 400 years ago in
Germany.
 It proved particularly useful in the Nebraska Sand hills.
 since 1990s straw bale construction has been
substantially revived, particularly in North America,
Europe and Australia.
History

4. Straw bale house

5.  There are two types of straw bales commonly used,
those bound together with two strings and those with
three.
 The three string bale is the larger in all the three
dimensions.
 Bale walls can be tied together with pins of bamboo or
wood ,.
 The bales may actually provide the structural support for
the building.
Methods

6. Two string bale -Three string bale

7.  MAKE A PLAN: Draw up the floor plan. Each section
of the exterior wall should be a multiple of the standard
bale length you plan to use.
 Decide what type of base you will use to support the floor
of the first story.
How to build a straw bale house?

8.  Prepare the foundation footings to be below the frost line in
cold climates, and floor to be level, on an attractive slope or
level ground.

9.  Build a frame of timber or metal. The frame transfers the
load of the roof down on to the foundation and should be
strong enough for this purpose.

10.  Stay dry during construction by putting the roof on
before going any further.

11.  Make the straw bale walls, not using hay, but using
straw. These need to remain dry, less than 20% moisture
content.

12.  Make U-shaped staves. The U staves are use to attach between
lined up blocks. when the desired height has been reached
some kind of strap can be placed around the entire wall.

13.  Plaster the walls. cover every last bit of exposed
straw otherwise fire is more easily started, and
dampness or vermin can get in.

14.  Put the window and door casings, securing them to framing
posts or to plastered walls outfitted with staves.

15.  Apply breathable paints which is free of artificial resins,
petroleum solvents but is weather and UV resistant.

16.  Dimensional lumber
 Straw bales
 Flyash concrete
 Earth materials
 Roofing
 Insulation
 Windows and doors
 Cabinets
 Paints, finishes and adhesives
 Floor coverings.
Materials for straw bale construction

17.  Compressed straw bales have a wide range of documented
R-value.
 Straw bales are very cheap, highly insulating from noise,,
cold and hot weather.
 Straw bales do not trap dampness in the house.
 Straw bales 100% biodegradable. These are made from a
waste product.
 Straw bale insulation is most effective in climates where
heating or cooling of home is essential for comfort.
Advantages

18.  Most contractors are unfamiliar with straw bale
building.
 Straw bale walls need to be kept dry as moisture is
detrimental to not only straw, but to the materials.
 Successibility to rot.
 High space requirement for the straw itself.
Disadvantages

19.  During construction the bales must be kept as dry as possible
at all times.
 The bale walls should be raised above ground level on a
masonry plinth.
 Wall building should preferably be done in the dry season and
the roof structure should go on quickly.
 Allow the bales to yellow or season before plastering is
begun.
Precautions

20. Thank you