Z Building Fabric Reference Specification

Z1 FABRICATING
Z10 Purpose Made Joinery
Z111 Purpose Made Metalwork: Mild Steel
Z112 Purpose Made Metalwork: Aluminium
Z113 Purpose Made Metalwork: Austenitic Stainless Steel
Z12 Preservative/Fire Retardant Treatments For TimberR
Z2 FIXING/JOINTING
Z20 Fixings/Adhesives
Z22 Sealants
Z23 Clay Based Mortar
Z3 FINISHING
Z30 Off-Site Painting
Z31 Powder Coating
Z32 Polyvinylidene Di-Fluoride Coating (PVF2)
Z33 Anodising
Z4 GLAZING
Z40 General Glazing
Z5 PLASTICS
Z50 Plastics

Z10 Purpose made joinery

CONSIDER:
• Locally sourced timber: Site first > Town > County > Region > Country > Continent > World .
• Use of any existing trees to be cut down as part of the works.
• FSC certified timber:
- Durable timbers do not all come from the tropical rain forests.
- Oak and many other species are durable and are available in the UK and Europe.
- There are durable softwoods as well as hardwoods.
• Off site prefabrication to reduce waste.
• Design structure for Normal 60 years of Long life 120 years: See A90.
• Design frame for deconstruction and salvage in future at end of design life. See A90.
• Softwood or Hardwood in place of steel structure.
• Grow trees to be available to replace roof and other timbers in 60-120 years.
• Floor structure, roof frame, decking and ramps are opportunities for timber structures made from home-grown structural timber, reducing the need for cement and aggregates on the project.
• Use of glued laminated timber where poor strength grade timber can be substituted in the middle of the section where it is least stressed.
- Potential to reduce the self weight of the section without significant loss of strength
- What adhesives are being used.
• Use of prefabricated pre-insulated breathing wall, floor and roof panels.
• Timber structure in place of concrete to avoid temporary materials (plywood and softwood) used in formwork.
• Beware of unseasoned untreated hardwood framed buildings: tree cutting is seasonal, plan projects around this issue.

REDUCE & REUSE:
• Use compound I section timbers - they reduce timber use.
• Use second-hand timber (recognised by FSC).
• Salvaged timber from existing building in:
- Softwood in stud walls, floors or roofs.
- Floor boarding.
- Doors, Windows.

AVOID:
• Illegally forested timber.
• Non-sustainably managed timber.
• Tropical rainforest timbers, (there are probably other species which will do the job you need from nearer the site).
• Endangered species of timber, (Check the CITES website).
• Clear felled virgin forest timber.
• Clear felled plantations if not replanted.
• Indonesian hardwood, most is illegally logged, destroys forests, communities and habitat.
• PEFC certified forest timber, it does not address all the issues adequately.
• Formaldehyde adhesives in compound or laminated sections See Z20.
• Synthetic adhesives if natural alternatives can do the job required.
• Adhesives if fasteners will do the job required.

FURTHER INFORMATION:
• FSC timber

Z111 Purpose Made Metalwork: Mild Steel

CONSIDER:
• Hot dip galvanized steel without paint as corrosion protection and decoration.

AVOID:
• Painted mild steel and painted galvanized steel.

Z112 Purpose Made Metalwork: Aluminium

CONSIDER:
• Recycled aluminium uses significant less energy to produce saving on CO₂ generation.

RECYCLING:
• Use recycled aluminium in preference to virgin aluminium.
• Design for recycling: avoid coatings as they discourage recycling due to the high levels of purity required in aluminium, PPC and PVF2 are more difficult; anodizing is an alloy of aluminium and is more readily recycled; mill finish is best but not everybody likes the oxides that form on aluminium. Mill finished aluminium reflects the colour of the sky: blue, white, grey or sun .

AVOID:
• Aluminium is readily available in natural state but requires considerable energy to extract from ore, and fossil fuel energy generates CO₂.
• Coating which currently discourage recycling of aluminium.

Z113 Purpose Made Metalwork: Austenitic Stainless Steel

RECYCLING:
• Stainless steel is all recycled so it is critical to collect all off-cuts and waste to return all to be recycled.
• Stainless steel is expensive so recycling makes financial sense.

Z12 Preservative/Fire Retardant Treatments For Timber

CONSIDER:
• BS and CP guide on where preservative treatment is essential.
• Building Regulations guide where fire treatment is required.
• Raising timbers above splash zone (say 200 mm.) and capillary attraction zone (say +200 mm.).
- Use more durable construction in this zone close to the ground.
• Use irregular permeable surfaces close to the building edge, to drain water ways, and provide a surface where water can not puddle and not be a platform to bounce and splash from.
• NHBC required treatment internally where the BS and CP did not, check before treating unnecessarily.
• Borax and Boron based preservative treatment (water soluble) most benign treatment know at the moment.
• Tanalith E in place of Tanalith (CCA)? But what is it made of?
• CCB is also available but does this warrant banning too?
• Preservative treated timber is toxic in landfill.
• Use of durable species hardwood instead of perishable softwood.
• Untreated, unseasoned, unfinished Oak is reported to be cheaper than preservative treated softwood.
• Zero or Low Formaldehyde boards (Chipboard, MDF, etc.) in place of conventional alternatives.

AVOID:
• Preservative treatment of timbers altogether if not essential
• CCA (Copper Chrome Arsenic) treated softwood.
• Creosote treated or coated softwood in all building types.
• Europe (therefore UK) has banned CCA and Creosote for new use in domestic buildings.

FURTHER INFORMATION:
• Timber preservatives.
• Alternatives to timber preservatives.

Z20 Fixings/Adhesives

CONSIDER:
• Zero Formaldehyde adhesives ( in chipboard, MDF, etc.) in place of conventional alternatives.
• Ballast in preference to adhesive and fastening (easily reused).
• Nails in preference to adhesive.
• Screws in preference to nails (removable if rust free) choose the metal and coating carefully.
• Bolts in preference to screws.
• Clamping (e.g. Lindapter) easily removed and reusable, in preference to bolting.
• Locational fixing in preference to fastening.
• Locational (compress and release into tight space).
• Locational pour or blown into pocket (loose insulation into joist space).
• Void filling: (insulation into timber framed cavities). See P10.

AVOID:
• Adhesives generally and formaldehyde-content in particular.
• Welding.
• Composites (less likely to be recyclable).
• Adhesives use in general, especially synthetic and petrochemical.
• Solvent curings.

ALERT:
• In the European Waste Catalogue, Waste Identification Code 08 04 Wastes from use of Adhesives and Sealants (Including Waterproofing Products) are classed as 'Deleterious Substances'.
• There are serious risks of killing people with cartridge operated fastenings (shot fired fixings).

Z22 Sealants

CONSIDER:
• Low voltage circuits to plug in low voltage equipment: e.g. Laptops, Broadband, Modem, CD, MD, Cassette players, Telephone chargers, etc.

AVOID:
• Sealant use in general, most are petrochemical.
• Solvent curing.

ALERT:
• In the European Waste Catalogue, Waste Identification Code 08 04 Wastes from use of Adhesives and Sealants (Including Waterproofing Products) are classed as 'Deleterious Substances'.
• Do not permit use of a licked finger as a method of tooling sealants.

Z23 Clay-based Mortar

CONSIDER:
• As alternative to cement based mortar- it will reduce CO₂ generated and used. It will ill set but not harden to the point of fixing. It can be reactivated with water.

Z3 Finishing

RECYCLING:
• Use recycled aluminium in preference to virgin aluminium, significant reduction in CO₂ generated.
• Design for recycling: avoid coatings as they discourage recycling due to the high levels of purity required in aluminium, PPC and PVF2 are more difficult anodizing is an alloy of aluminium and is more readily recycled, mill finish is best but not everybody likes the oxides that form on aluminium.
• Mill finished aluminium reflects the colour of the sky: blue, white, grey or sun.

Z30 Off-site painting

CONSIDER:
• Some paints are supplied in cardboard drums and are compostable.
• Some natural paints are compostable along with the cardboard drum.
• Paints listed in British Museum Schedules for museums.
• Absorption of UV light.
• Natural traditional paints, stains and oils.
• Mineral paints which chemically bond with porous backgrounds, up to 100 years life.
• Paints with long life 10 years external or 20 years internal between coatings.
• Powder coatings in preference to paint.
• Galvanized steel without paint, See Z111.

REUSE:
• Store materials to prevent deterioration.
• Permit the use of opened and resealed and unopened tins from the contract to be stored on site for use in snagging.
• Permit the use of unopened tins from the contract to be stored on site for use in and in 6 month defect repairs.
• Permit the use of unopened tins from the contract to be stored on site for use by the FM in maintenance .of the building in use

AVOID:
• Most conventional paints which are compounds of petrochemicals and volatile organic solvents.
• High VOC paints.
• Synthetic paints.
• Aggressive paints which will affect the exhibits in museums and art galleries.
• Painted steel structure.

ALERT:
• Paint and paint cans are classed as 'Hazardous Waste'. Disposal is prohibited in normal landfill sites.

FURTHER INFORMATION:
• Paint for joinery

Z31 Powder Coating

CONSIDER:
• Uncoated aluminium (but reduces component life).
• Powder coatings in preference to paint.
• Anodizing in preference to powder coating for recycling potential, See Z33.
• Long life and infrequent recoating.
• Low to Zero VOC.

AVOID:
• Polyester powder coated aluminium- it is less likely to be recycled.

Z32 Polyvinylidene Di-Fluoride Coating (PVF2)

CONSIDER:
• Uncoated aluminium (but reduces component life).
• Coatings in preference to paint.
• Long life and infrequent recoating.
• Low to Zero VOC.

AVOID:
• PVF2 coated aluminium; it is less likely to be recycled.
• Relatively short life in marine conditions.

Z33 Anodizing

CONSIDER:
• Anodized coated aluminium is more likely to be recycled than PPC See Z31.
• Anodizing is anodic oxide coating, an oxide of aluminium.
• Uncoated aluminium (but reduces component life).
• Coatings in preference to paint.
• Long life and infrequent recoating.
• Low to Zero VOC.

Z40 Glazing

CONSIDER:
• Exclusion of UV light, use PVB Interlayers in laminated glass.
• U Values of 1.0 W/m²K are achievable.
• Use Double Glazed Sealed Units to BS 5713 and BSI Kitemarked.
• Use Low E glass generally, not just high level.
• Use Argon, Pentane or CO₂ in cavities.
• Timber: Hardwood, Heartwood of softwood, Slow grown timber, recycled timber.
• FSC approved timber sources and timber based materials See Z10.
• Uncoated aluminium (but reduces component life).

AVOID:
• Single glazing, except in remote difficult to get to places where replacement due to failure will cause difficulty e.g. above shopping malls.
• Condensation on inner face.
• Excessive glazing on north face (heat loss in winter).
• Excessive glazing on south face (heat gains in summer unless it is managed and exploited).
• PVC See Z50.
• Powder coated and painted aluminium.
• CCA (Copper Chrome Arsenic) treated softwood, See Z12.
• Double Glazed Sealed Units only offering U Value 2.0 W/m²K.

FURTHER INFORMATION:
• Glass and Glazing

Z50 Plastics

CONSIDER:
• Foamed bio-plastics, made of starch from potatoes, etc
Foamed plastics: found in: thermal insulation, tile backing boards, Insulated plasterboard, joint fillers, fridge/freezers, composite cladding.
• ZODP Zero Ozone Depletion Potential
• Low-Zero Global Warming Potential
• Low Greenhouse Gas Potential
• Manufactured without the use of, nor containing, CFCs, HCFCs, HFCs and HFAs as blowing agents.

RECYCLING:
• Use recycled plastic.
• Very little PVC is recycled. PVC that is recycled is used in the cores of PVC windows. Recycling is crucial to the pro-PVC argument. Environmentally, without recycling, PVC falls short of other materials (such as timber) in terms of environmental impact.

AVOID:
• Virgin plastics (non-renewable).
• Petrochemicals (non-renewable)
• PVC should be avoided since it uses 8 out of 15 of the most toxic chemicals in its manufacture
• Chlorine is part of the process: Ozone Depleting Potential
• Off gasses and toxic in fires.
Chlorinated Polyethylene is another one with Ozone depletion potential due to chlorine in manufacture but the change to the polyethylene probably means it cannot be recycled.

FURTHER INFORMATION:
• Plastics in production