GUYANA STANDARD

Section 7 - Use of Guyana Hardwood in ConstructionScopeThis code provides guidance on the use of

Guyanese timber species for construction purposes. It includes recommendations on quality, engineering properties and the various design consideration and principles for simple members, built up components, composite structures and sub structures incorporating other materials.

Materials and SpeciesThis code complies to the British Standards BS

4978 : 1996 “Specifications for visual strength grading of softwood” and BS 5756 : 1997 “Specification for visual strength grading of hardwood:

Some of the species which are considered suitable for construction purposes to which the provision of this code is applicable are listed in Table 1.

Table 1Standard Name Approximate

Density (kg/m3 ) at 18% moisture content

Bullet Wood 900

Greenheart 1030

Kabukalli 830

Mora 910

Purpleheart 860

Silverballi 600

Wallaba 950

Simarupa 430

Wamara 120

Design ConsiderationsThis code specifies design requirements for

two general categories of structures:(i) light frame domestic buildings(ii) heavy structures, including industrial,

commercial, institutional and other public buildings, and other major engineering structures requiring engineering design inputs.

. Design Considerations The methods of design of timber structures are:(i)Working Stress Design - which is an elastic

design method which involves the application of standard engineering principles and design standards.

The two categories of structures above utilise this method of design.

(i) Limit State Design (ii) Simplified Design methods - based on load-

span tables, design nomograph and other design aids.

Design StandardsMinimum Design Standards for Low rise

Buildings Tables 9,10,11,12, and 13 of the Code gives the

Span, maximum spacing and dimensions of floor beams, floor joists, rafters and ceiling joists, purlins and columns respectively.

For Floor beams the maximum imposed load is – 2.0 KN/m2

For floor joists, the max. dead load = 0.8 KN/m2

live load = 2.0 KN/m2

Design StandardsTables 2 to 5 of the Code gives the various

strengths of the timber when tested Tables 9 & 10 gives the maximum imposed

loads for Single Span floor beam and floor joist respectively, with fixed live and dead loads.

General Review by the AuthorityAll proposed technology will be considered and

examined by the Authority or an experienced engineer appointed by the Authority, to determine whether the building is acceptable.

The building Engineer can/must recommend changes which are needed to make the building resistant to the environmental hazard.

It is the responsibility of the developer to show by supporting documentation that the building proposed is structurally adequate.