Types Of Stairs

Wooden stairs of non-impregnated timberare used mainly indoors, buttheycanal-so be placed outside if they are under shelter (Figure 16.8). Pine, oak, ash, beech and elm are hard-wearing materials and can often be used with a treatment consisting of soap or linseed oil. The timber should be of a high quality and should not have any knots. Handrails and banisters can be made of maple, which has asmooth surface well suited for this purpose.

It has become common to use laminated timber in recent years. Here phenol-resor-cinol-formaldehydeglue(PRF) iswidelyused, but caseinglueisalsosuitable. Outdoor wooden stairs are often treated with fungicides.

Stone stairs are particularly well-suited for outdoor use. Stones can be used direct from the quarry or cut. Granite is the most hard-wearing variety. It is also possible to use pieces of quartzite slate for the steps. It is usual to have a forged iron balustrade with natural stone stairs.This is set in pre-bored holes with floating sulphur.The sulphur solidifies ina few minutes andprevents any rustgettingtothefoot.

Brick stairs can be used inside and outside and are usually built from ordinary bricks. Foroutdoor placing vitrified bricks should be used.

Concrete stairs can be used inside and outside. Uncovered concrete stairs have a tendency to get dusty. It is normal to cover them with ceramic tiles or terrazzo.

Cast iron and steel stairs came intouse in late nineteenth century and are often used for fire escapes.They are usually galvanized or painted.

16.7

The door of a lap cottage with a protective layer of birch bark fixed with branches of bracken.

16.7

The door of a lap cottage with a protective layer of birch bark fixed with branches of bracken.

Wooden and stone stairs use the most favourable raw materials, environmentally speaking. They also have low levels of pollution and energy use in production.

Within a building, stairs have practically no side effects. Exceptions that can lead to polluting emissions are impregnated wood stairs, and some paints used both on iron and wooden products. Steel stairs and reinforced brick and concrete stairs can increase the electromagnetic fields in a house.

All types of stairs have a re-use potential, especially wooden stairs mounted in modular parts for simple dismantling, dry stone stairs, brick stairs laid in a weak mortar, standardized steel stairs, etc. Certain prefabricated concrete stairs are also suitable for re-use. Products cast in situ can be recycled as fill or aggregate for low quality concrete work. Steel products can be easily recycled through smelting.

Stone, brick and concrete are inert and relatively problem free as waste. Impregnated timber must be deposited at special dumps or incinerated at high temperatures with special cleaning equipment.

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