ncof.co.uk/marie-alice-sale-a-caminar.php Cement renders can be finished with a lime putty render topcoat. The three layers of render should be progressively weaker to reduce the potential for cracking caused by having too brittle an external layer. Lime putty renders resist cracking and hold coloured oxides well. Earth renders are gaining popularity as concerns about their effectiveness have been addressed. The main advantages of using earth renders are to do with minimising environmental impact and time spent in preparation and application.
Earth renders significantly reduce the embodied energy of the building see Mud brick. Render can be applied directly to the face of a strawbale wall, particularly earth renders. Cement has a long life but does not bond well with straw and requires a supporting medium. A common method has been to fix chicken wire to the wall surfaces to be rendered by sewing lighter gauge wire through the walls at mm spacing and by pinning it with staples made from medium gauge wire 2mm. A number of practitioners are moving away from the use of chicken wire and emphasise working the render into the bale surface instead.
There are various ways of improving adhesion and reinforcing the render skins, including the use of fibreglass netting instead of chicken wire. Curved corners, window and door returns, and all junctions between dissimilar materials are best dealt with by having expanded metal mesh as the substrate for any render. An increasingly popular method of applying render employs a concrete pump or spray, as used to make swimming pools.
Renders should not create non-breathing skins that prevent the movement of air and encourage mould, fungus and decomposition of the straw. The use of light colours in the finishes of this living room enhances the effect of natural timber. There are no formally established standards for strawbale building but, like any building material, the best performance comes from following acknowledged best practice. Although it may not be ideal, if bales do get slightly wet they can often be dried out sufficiently to be usable. Strawbale walls are very resilient and in the event of damage they can be repaired.
Wet bales can be taken out and replaced and even fire damage can be repaired under insurance. Amazon Nails. Information guide to straw bale building: for self builders and the construction industry. Amazon Nails, Todmorden, UK. Ausbale: promoting the art and science of straw bale building. Mudgee, NSW. Dorniak, B. Rendered strawbales successfully tested for bushfire. Earth Garden. Hodge, B. Building your straw bale home: from foundations to the roof.
Landlinks Press, Collingwood. Lacinski, P, and Bergeron, M.
Serious straw bale: a home construction guide for all climates. Magwood, C, and Mack, P. Straw bale building: how to plan, design and build with straw. Partridge, H. Straw bale construction. Environment design guide, PRO Australian Institute of Architects, Melbourne. Steen, A and Steen, B.
The beauty of straw bale homes. Materials Embodied energy Waste minimisation Construction systems Lightweight framing Brickwork and blockwork Cladding systems Concrete slab floors Insulating concrete forms Autoclaved aerated concrete Precast concrete Mud brick Rammed earth Straw bale Green roofs and walls. Straw bale.
Straw bales were first used for building over a century ago. Structural capability The structural capability of straw bales is surprisingly good. There are many examples of multi-storey buildings in framed strawbale construction. Photo: Paul Downton Straw bales in the city. There is no location that strawbale building cannot adapt to.
Thermal mass Straw bales have very low thermal mass, being composed, by volume, mostly of air. Insulation Straw bales have excellent insulation properties, among the most cost effective thermal insulation available see Insulation.
Centimetre for centimetre, straw has similar insulation value to fibreglass batts. A typical strawbale wall has an R-value greater than Dollar for dollar, the insulation value of a strawbale wall exceeds conventional construction. Photo: Paul Downton Straw bales can accommodate any window shape and occasionally be used for internal walls. Sound insulation Straw bales also provide cost effective sound insulation, which contributes to the liveability of this kind of construction and can be quite marked. Fire resistance Straw bales are tightly packed and covered with a skin of render.
Vermin resistance A completed wall has excellent resistance to vermin and the normal termite protection measures required in the BCA are generally sufficient.
straw bale building blocks Building Stone, Natural Building, Building A House, Straw Bale. Visit Straw Building Blocks Make Warm Sustainable Homes. Abstract – The article describes the current straw bale building situation in the project “Promotion of is based on a block system, making the designs very easy.
Photo: Paul Downton Laying straw bale. Durability and moisture resistance Provided the straw is protected and not allowed to get waterlogged, strawbale buildings may have a lifetime of years or more Amazon Nails Toxicity and breathability The natural materials of strawbale construction are safe and biodegradable.
Photo: Alex Makayev Photography Straw bale in the bush. Environmental impacts Straw is a waste product; it cannot be used for feed, like hay, and much of it is burned at the end of the season. Buildability, availability and cost Strawbale construction rates highly for buildability because it can be very straightforward and is well suited to workshop and volunteer based building programs. Typical domestic construction Construction process Strawbale construction methods are all variations on ways of achieving good bale compression to minimise settlement and movement.
Typical details All structural design should be prepared by a competent person and may require preparation or checking by a qualified engineer. Source: Paul Downton Strawbale wall panel — typical detail simplified. Footings A strawbale wall requires footings with a similar load carrying capacity to that required for a masonry wall, although a straw wall is generally lighter one mud brick weighs about the same as a straw bale. Source: Paul Downton Bottom plate detail. Loadbearing walls The earliest strawbale buildings of over a century ago were loadbearing.
Photo: Paul Downton Another kind of base plate with a lower profile and no crosspieces.
Photo: Paul Downton Ladder frame being filled with pea gravel before frame and bale placement. Frames Although it is possible to build strong and effective single storey strawbale structures, it is often easier to ensure BCA compliance and predictable engineering outcomes if the walls are constructed as infill elements between loadbearing frames. Photo: Paul Downton A chain saw is the tool of choice for cutting and trimming straw bales. Photo: Paul Downton A typical frame. This two storey house uses only recycled and plantation timbers. Photo: Paul Downton The use of frames makes almost any kind of opening possible in strawbale construction.
Joints and connections Strawbale walls can be joined to almost any construction provided attention is paid to flashing details, preferably with the assistance of a competent architect or designer. Photo: Paul Downton The middle plate and compression wires can be seen in this detail of a timber framed, three storey strawbale townhouse. Fixings It is possible to fix substantial loads to loadbearing and non-loadbearing strawbale walls by forming clamps made from planks of timber on either side of the bales, tied through the wall with high tensile wire and tensioned by grippling or twisting.
Fire hazard tests were carried out in before a school was constructed in Issy-les-Moulineaux, which showed that the fire risk of this kind of building is very low. Lined with Douglas fir and larch, two types of wood that grow in France and are naturally rot-resistant, the school opened its doors in September There are solar panels for water heating, photovoltaic panels for electricity, a rainwater collection system for the toilets and garden — everything in the building has been conceived to have as little impact as possible on the environment.
But we are hoping to switch to recycled fuel with a system that collects used frying oil.
Especially because the amount used by the school is very little. Natural rubber, for example, was used for the floors. Other volatile organic compounds used in paint or varnishes are just as problematic, containing components such as benzene, acetone, or perchlorethylene. Tropical wood, often used outside due to its rot-resistant qualities, is another material that the school has said no to. The straw bale projects we are undertaking create a lot of local work. Not to mention the low operating costs — these highly energy-efficient buildings are very cheap to run.
Everything has to be better than good. Everything has to be proven, demonstrated. The design has to be extremely precise, down to the last detail. Before assembling the bale walls, we laid black locust boards on the stone foundation to create a moisture break. Next came the layers of bales. Bales were layered using a running bond i. For stability, each bale was staked to the two bales below it using locally produced oak surveying stakes.
Although the bale walls are not tied to the foundation, they are attached to the timber frame, which sits on the foundation. All bales near frame posts were tied to the posts by wrapping bale twine around the oak stakes, then wrapping the twine around screws that were screwed into the posts. The new building uses a similar bale stacking method to the old building, although Andy Mueller, of Greenspace Collaborative, who did the bale and plaster work, had many improvements on our older method.
What is best for one project may not be appropriate for the next. Our bales were made from rye straw, which is a local, sustainably harvested spring crop.
We used 2-string bales that weighed approximately 35—50 lbs.