CONSTRUCTION MATERIALS handbook

MATERIALS INTRODUCTION

When people talk about ‘green’ materials what do they mean?Broadly speaking ‘green’ materials are from renewable sources and are environmen-tally responsible over the life of the product. They may be assessed using criteria from the list below.(This information was based on Lynn Froeschle’s article, “Environmental Assessment and Specification of Green Building Materials” October 1999 issue of The Construction Specifier.)

Resource Efficiency is achievable by using materials that meet the following criteria:

Recycled Content: Products with identifiable recycled content, including postindustrial content with a preference for postconsumer content.

Natural, plentiful or renewable: Materials harvested from sustainably managed sources preferably with independent certification (e.g. certified wood)

Resource efficient manufacturing process: Products manufactured with resource-efficient processes including reducing energy consumption, minimizing waste (recycled, recyclable and or source reduced product packaging), and reducing greenhouse gases.

Locally available: materials, components, and systems found locally or regionally saving energy and resources in transportation.Salvaged, refurbished, or remanufactured: Includes saving material from disposal and renovating, repairing, restoring, or generally improving the appearance, performance, quality, functionality, or value of a product.

Reusable or recyclable: Select materials that can be easily dismantled and reused or recycled at the end of their useful life.

Recycled or recyclable product packaging: Products enclosed in recycled content or recyclable packaging.

Durable: Materials that are longer lasting or are comparable to conventional products with long life expectancies.

RECYCLING+ REUSE

locally sourced nationally sourced internationallysourced

KNOW YOUR SYMBOLS& WHAT THEY STAND FOR

LOCAL MAY DIFFER BETWEEN PRODUCTS

DEFINING ‘GREEN’ MATERIALS

Indoor Air Quality (IAQ) is enhanced by using materials that meet the following criteria:

Low or non-toxic: Materials that emit few or no carcinogens, reproductive toxicants, or irritants as demonstrated by the manufacturer through appropriate testing.

Minimal chemical emissions: Products that have minimal emissions of Volatile Organic Compounds (VOCs). Products that also maximize resource and energy efficiency while reducing chemical emissions.

Low-VOC assembly: Materials installed with minimal VOC-producing compounds, or no-VOC mechanical attachment methods and minimal hazards.

Moisture resistant: Products and systems that resist moisture or inhibit the growth of biological contaminants in buildings.

Healthfully maintained: Materials, components, and systems that require only simple, non-toxic, or low-VOC methods of cleaning.

Systems or equipment: Products that promote healthy IAQ by identifying indoor air pol-lutants or enhancing the air quality.

Energy Efficiency can be maximized by using materials, components, and systems that help reduce energy consumption in buildings and facilities.

Water Conservation can be achieved by using products and systems that help reduce water consumption in buildings and conserve water in landscaped areas.

Affordability can be considered when building product life-cycle costs are comparable to conventional materials or as a whole, are within a project defined percentage of the overall budget.

DEFINING ‘GREEN’ MATERIALS

MATERIALS INTRODUCTION

Time to maturity varies between species - generally softwoods mature faster than hard-woods - and species are suited to different applications.

MATERIALS TYPES

TIMBER

Timber products are widely used in the construction industry. In small buildings they can be used for up to 95% of the componenets from structure, cladding, insulation to furniture.

Timber has good thermal conductivity and compared with its weight is 50% stronger than steel.

Timber has natural anti-bacterial properties and resists the growth of moulds.

All parts of the tree are usable, re-usable and or recyclable

Coppicing is a traditional method of forest management that produces usable timber on a 7-20 year cycle.Sweet chestnut is the most commonly coppiced species in Sussex, but hazel, alder, ash and oak are also suitableCoppicing produces small section short lengths timber which can be finger jointing to pro-duce longer lengths

Sweet chestnut coppiceEast Sussex

1 KG = 1.5 KGstrength to weight

TREES

When forests are well managed with mixed species and selective harvesting the quality of the timber is higher and the environment benefits with a reduction in soil errosion and river pollution and an increase in biodiverstiy.

Timber grown in this way is a sustainable material. However, most commercial forests are monocultures and are clear cut causing environmental degradartion and loss ofhabitat for wildlife

The oldest tree on earth 9550 years old in Sweden

oak & beech100yrs

conifers 80yrs

deciduous soft-wood 30-60yrs

mixed hardwood forestlogging with horses allows for selective harvesting minises damage & is sustainable

clear cutting & slash burn cause habitat devestation, slow regrowth, soil erosion & river pollution

PROCDUCEDFROM TREES

METAL PRODUCTSTIMBER PROPERTIES & PRODUCTS

finger jointed timber is suited to joinery - hw & sw are used for windows

MATERIALS TYPES

PROCESSINGProcessing timber varies from very low tech to high tech. We import timber and timber products from around the world.Some of these could be produced in the UK.

1 kg TIMBER contains 50% CARBON which binds 1.8kg CO2. Carbon stays bound until wood is burned or rots

Ave. timber house contains 20 tons of timber binding 36 tons

source: ‘The Ecology of Building Materials’ Bjorn Berge

TIMBER PROPERTIES & PRODUCTS

High tech glulam

Low tech log cabin

roof shinglesor shakes rigid insulation cel-

lulose board from timber waste

ply, MDF, OSBused structurally& decoratively

timber doorsexternal & internal often reclaimed

many varietiesand qualities of flooring

internal joinery high grade wood hard to abtain

furniture & fittings ...

chestnut rain-screen - there are many varieties of external boarding

sawn softwood timber structure

CLAY & EARTH are locally available in most locations, are recyclable or reusable.They are traditional materials formed into many products some of which are produced locally.

Peat walls and Rammed earth are very low tech methods of construction. Rammed earth often uses some plant material with the earth which is tamped down in layers.

Unfired blocks are made of clay, sand and sawdust and are used as part of breathing walls.

Fired bricks can be fired at various temperatures. They can be reused for generations providing a lime mortar is used. Local bridkwork are Chailey and Freshfield Lane

Clay Tiles Sussex has a long history of producing clay hanging and roof tiles. Local makers include Keymer Tiles Ltd, Burgess Hill and Tudor Roof Tile Co. Lydd, Kent

Paint clay based paints funtion as part of breathing wall systems and have zero VOCs

CHALK & LIME is a significant and plentiful local resource in and around Brighton.

Lime mortar is a sustainable product which allows bricks and stone to be reusd.

Lime render is used as part of breathing wall systems Lime paints are soft with very low or zero VOCs

STONE has been used in buildings for millenia. It is heavy, cumbersome and expensive to move but very durable and reusable.

Flint is local to Brighton and is used for street cobbles, in walls and is knapped. Available from Brighton Beach in its raw state.

Wealden Sussex Sandstone can be sourced from Lambs Philpots Quarry, West Hoathly, Sussex

rammed earth & timber frame construction

square knapped & cobbled flint walls flint shingles

Philpots Quarry, Wealden Sussex sandstone

unfired clay blocks

fired clay tiles

MATERIALS TYPESPROCDUCEDFROM CHALK

STONE PRODUCTS

chalk

limewashed & waxed walls

WASTE provides many potential building materials both in reprosessing and using materials in new and unusual ways. The possibiliteies are nearly endless...

PLANTS other than trees have many non structural uses in buildings. They tend to have a short, fast lifecycle, are renewable, sustainable, plentiful, readily available, inex-pensive and are often waste or byproducts from farming or other industries.

Straw is produced locally and can be used loose in rammed earth walls or as bales either small bales for in situ or large bales in prefabricated panels

Hempcrete is produced from the flax plant which can be grown locally. Flax fibres are very strong, are naturally resistant to insects and do not burn readily.Hemp fibres embeded in the lime fossilise locking carbon. Other products in-clude linseed oil, in insulation and draft exclusion. Turf and sedum rooves form a living coverings with environmental benefits

Thatch once common is now mostly imported from eastern europe

MATERIALS TYPES

carboard tube block

Westborough primary school cardboard tube

Wat Pa Maha Chedio Kaew glass bootle

Rural Studio tyre church

Nancy Robbens restaurant using waste products