J. SWIDERSKIAmong the areas, set by the Director-General of FAO, round which the Organization's efforts should be concentrated, War on Waste is one of the more important.
Waste - the economically avoidable loss of produce or its improper use - is a luxury which cannot long be afforded even in the richest countries and is a serious obstacle to development efforts in new countries, where it can seriously limit their chances of expansion. In forestry, waste occurs at all stages - from growing and managing forests, through logging and transport to the industrial processing of wood and placing the finished product in its final destination.
One of the important types of waste is wood damaged by fungi or insects. Much of this state is preventable through proper wood preservation, but is not prevented largely because of failure to recognize its magnitude.
The Forestry and Forest Industries Division of FAO has always attached much importance to wood preservation. Here is a lecture on the subject delivered by the Chief of the FAO Forest Industries and Utilization Branch, at the International Seminar on Wood Preservation in Tropical Countries, sponsored by FAO/IUFRO/DSE (Deutsche Stijtung für Entwicklungsländer) at Feldafing near Munich, September/October 1967.
The importance of wood preservation in tropical countries stems not only from the fact that large quantities of timber are involved but also because the rate of timber consumption in these countries is expected over the period 1961-75 to expand at a rate more than three times that in the rest of the world.
Climatic and biological conditions make wood preservation in the tropics even more important for four basic reasons:
1. In tropical countries particularly there are numerous species of wood-destroying insects and fungi.2. Hot and humid weather in the tropics facilitates and speeds up any decomposition of wood.
3. Only a limited number of the great variety of tropical species are naturally durable. (In the Philippines, for example, out of 3500 tree species, less than 10 percent are reported to be naturally durable.)
4. The lines of supply from the tropical forest to the final destination of the timber usually extend over comparatively long distances and the risk of damage by insects or fungi is a constant threat even after the finished product has arrived at its final destination.
These four factors make the preservative treatment of timber an indispensable condition for the proper development of wood utilization in tropical countries. Nevertheless the amount of timber which is given preservative treatment is rather limited in most of the tropical countries. In some cases, preservation facilities are almost nonexistent. In others, they are expanding too slowly to meet the real needs.
Table 1 shows the estimated consumption of wood used in the round and of sawnwood in tropical countries in 1966.
TABLE 1. - ESTIMATED CONSUMPTION OF ROUNDWOOD (POLES, POSTS AND PILINGS) AND SAWNWOOD USED IN TROPICAL COUNTRIES IN 1966
|
|
Quantity |
Estimated value |
|
|
Million m3 (s) |
Million m3 ®1 |
Million $ |
|
|
Wood used in the round |
40 |
40 |
480 |
|
Sawnwood |
30 |
54 |
1650 |
|
TOTAL |
70 |
94 |
2130 |
1 Estimated roundwood equivalent.
The data do not include wood consumption for wood-based panels such as veneer, plywood, fibreboard, and particle board. The present volume of wood-based panels used in tropical countries is estimated to amount to 1.6 million cubic metres and consumption is expected to double by 1975. This also is a very important field of activity for wood preservative treatment but it is not dealt with in this paper mainly because of different treatment patterns and their economic implication.
The estimated total of roundwood and roundwood equivalent of sawnwood used in the tropics in 1966 was about 94 million cubic metres, with an end product value of around $2100 million - a figure which gives some idea of what is at stake.
How much of this considerable expenditure might have been saved if the wood used had been properly treated and adequately preserved? The situation varies from category to category of wood, from species to species, and from country to country. It differs with the different preservation methods applied and depends also on the final application of the wood. Difficult though it is to give with any degree of accuracy specific figures of potential savings as a result of preservation treatment, an attempt should be made to arrive at least at approximations in order to realize the magnitude of the problem and to supply a measurable answer to the question: How important really is wood preservation to the developing countries of the tropics?
Rough calculations indicate that pressure preservative treatment of every 1 percent of wood presently used in tropical countries could lead to savings of not less than $75 million as a net result of prolonging the natural durability and hence the service life of the wood utilized. This figure compares very favourable with the actual costs of preservation, estimated at around $7 million. In other words, each dollar spent on preservation yields more than ten times its value in savings by prolonging the service life of the wood used.
Some approximate values to illustrate the economic significance of wood preservation in tropical areas are given in Table 2.
TABLE 2. - APPROXIMATE VALUES INDICATING THE ECONOMIC SIGNIFICANCE OF WOOD PRESERVATION IN TROPICAL AREAS (PERCENT)
|
Ground contact timbers |
Percent year |
|
Average cost of untreated timber1 |
100 |
|
Average cost of pressure treatment2 |
25-35 |
|
Investment cost for pressure treatment3 |
0.8-1.2 |
|
Estimated savings arising from prolonged service life of treated timber4 |
66-72 |
1 Nonexportable secondary species or subexport quality of mixed hardwoods in Malaya and Nigeria. - 2 Treatment of a fence post to a retention of 12 g dm of pressure preservative is assumed. - 3 It is assumed that the investment cost of an installed pressure treatment plant (40 m long and 1.24 m diameter) of a daily capacity of 18 m³ is about 517000; it is also assumed that the equipment will be written of, over a 10-year period. - 4 It is assumed that the life of an untreated post is approximately 2 years and the life of a treated post is about 10 years.
The expected trend in future wood consumption makes the preservation of wood of even greater importance in the tropical countries than in the rest of the world. According to the FAO study, Wood: world trends and prospects,1 consumption in the tropics of the categories of wood used in the round and sawnwood (Table 3) is expected to increase by 70 percent during the period 1961 to 1975, while the corresponding figure for the rest of the world is no more than 22 percent.
1 Unasylva, Vol. 20 (1-2), Nos. 80-81, 1966.
FIGURE 1. - A typical vacuum/pressure impregnation plant for tropical conditions.
The Kampong Selut Low-cost Housing Scheme.
TABLE 3. - ESTIMATED CONSUMPTION OF ROUNDWOOD (POLES, POSTS, PILINGS) AND SAWNWOOD IN TROPICAL COUNTRIES IN 1960-62 AND 1975
|
|
World |
Tropical countries |
||||||
|
1960-62 |
1975 |
1960-62 |
1975 |
|||||
|
(s) |
® |
(s) |
® |
(s) |
® |
(s) |
® |
|
|
Millwork cubic metres |
||||||||
|
Wood used in the round |
188 |
188 |
185 |
185 |
33 |
33 |
54 |
54 |
|
Sawnwood |
346 |
623 |
427 |
769 |
18 |
45 |
43 |
79 |
|
TOTAL |
534 |
811 |
612 |
954 |
51 |
78 |
97 |
133 |
As can be seen from Table 3, world consumption of wood used in the round and sawnwood over the period 1961-75 is likely to rise from over 800 million cubic metres (in roundwood equivalent) to over 950 mil lion cubic metres - while the corresponding figures for the tropical countries are 78 million and 133 million cubic metres.
As is well known, wood preservation practice in tropical countries is still far below the real needs. Realistic targets for expansion of the preservation industry will, of course, vary for individual countries. For example, should the target be an average of, say, 5 percent of the amount of wood presently consumed in the tropics as a whole, it could result in savings of not less than $400 million; should the target be 25 percent, the resulting savings might be over $2000 million - a very impressive figure indeed - at a cost of less than one tenth of this value.
In these rough calculations it has not been possible to take into account all the factors involved, for example:
(a) additional benefits resulting from avoiding the frequent replacement of untreated wood;(b) prevention of losses caused by damage to untreated wood in structures, installations, etc.;
(c) impact on overall wood consumption of the prolonged life of properly treated timber;
(d) impact of comparatively large quantities of timber which reach their final destination outside market trade and rarely are likely to be treated.
However, in order to include all these factors in approximate calculations, careful studies are necessary, which call for much more information than is currently available. When one takes into account the complex interrelationship of all the factors involved, there is an undoubted need for such research which should be carried out in the future in individual countries, especially in the tropics. However, for the time being, the approximations already given may suffice to show the order of magnitude of the problem involved.
The economic value of wood preservation is convincingly demonstrated by the extended service life that pressure treatment with creosote or multisalts can impart to the original timber. Untreated railway sleepers may last 5 to 6 years; treated sleepers, 20 to 25 years; untreated transmission poles may stand for about 4 to 6 years; properly impregnated poles for 30 years; untreated mining timber may last 2 to 3 years; treated timber up to 20 years or more; untreated timber for cooling towers may last for an average of 10 years; suitably pressure treated timber for 25 to 30 years.
Scattered through the technical literature is information about the cost and effectiveness of preservation in relation to specific cases. As reported from India, for example, the cost of treated chir pine (Pinup roxburghii) transmission poles, railway sleepers and building timber in India is approximately 20 percent higher than that of the untreated products. At the same time, the service life is 4 to 8 times as long. The annual expenses per ton of timber are 2.5 to 3.5 times lower than those for untreated timber.
From another source we know that for softwoods the cost of preservation (in a temperate zone) represents one fifth to one sixth of the final cost of the timber. Treatment of the timber ensures a service life three times as long as that of untreated wood.
Immediate improvement of the present poor situation in wood preservation in tropical countries would result in a great reduction in the heavy losses caused by damage to the wood. Though few facts and figures are available to show the amount of wood saved by preservation, there are some data which indicate losses resulting through a lack of preservative treatment.
In the United States, the annual bill for damage by insects, decay and marine borers is reported to amount to $500 million a year. Figures are available which show that for all United States railways for the 52-year period, 1898-1949, the average savings due to the use of treated cross-ties was $129 million annually. In Hawaii, the cost of repairing termite damage is officially set at $3 million per year. An example from Norway quoted at the FAO wood preservation meeting held at Rome in 1959 estimated that annual losses of wood in service correspond to the cost of pressure impregnation of the whole annual sawnwood consumption of the country.
COMPARATIVE FIGURES
Losses resulting from lack of preservation are strikingly high compared with the costs of preservation. As indicated earlier, these costs show that the average cost of wood preservation in tropical countries may amount to about 20 to 30 percent of the cost of the timber used and that the service life of treated wood may be 5 or more times as long.
The estimates for Sweden are that treatment amounts to some 25 percent of the cost of the wood and that the increase in service life ranges from 300 to 500 percent. In Sweden there are 4.5 million poles; their creosote pressure treatment results in annual savings amounting to $6 million, resulting from the prolonged service life of 15 to 45 years.
For Swedish railways the treatment of sleepers means savings of at least $10 million per year. On top of that, of course, there are savings resulting from not having to replace untreated wood. As one Swedish expert put it: "Treated wood is the best business from the consumer's point of view."
Despite these outstanding benefits from wood preservation, the quantities of wood treated in most of the tropical countries are strikingly low.
In the Philippines, less than 1 percent of the timber locally consumed is treated. A similar situation exists in Thailand, where in 1966 only 16000 cubic metres of wood were treated for use as building timber and sleepers.
POOR UTILIZATION OF EXISTING CAPACITY
A common phenomenon is the poor utilization of existing capacity in certain countries. In Argentina, for example, where the output of preservation plants amounted to 250000 cubic metres in 1966 (that is, about 4 percent of local industrial timber consumption), the actual capacity was 2½ times higher. In Malaysia, the capacity of preservation plants amounted to 240000 cubic metres of timber, but only a small part of this capacity was actually utilized. In Indonesia, wood preservation capacity is about 90000 cubic metres a year, but the actual output declined between 1956 and 1964 from 24000 cubic metres to the negligible amount of slightly more than 1000 cubic metres.
On the other hand, figures showing the quantities of wood preserved in many developed countries are considerably higher. In Australia, for example, the volume of treated timber is estimated as 2 million cubic metres a year, which corresponds to 50 percent of the yearly consumption.
In New Zealand, 750000 cubic metres, that is, 40 per cent of the total consumption of sawn timber in 1966, were treated. So also were 250000 cubic metres of poles and fencing materials. In the United States, about 7.2 million cubic metres of timber were treated with preservatives and fire retardants in the preservation industry. That was an increase of 8 percent as compared with the figure for 1964. The amount of wood used in the round constituted 25 percent of the total consumption of wood of this category. In Sweden, about 10 percent of the roundwood and sawnwood presently consumed is treated. Some Swedish experts consider that 20 percent would be A reasonable estimate of the quantity which should be treated. In the United Kingdom, the amount of soft- sawnwood treated amounts to 10 percent of the total consumption.
LESS TREATED TIMBER IN THE TROPICS
From the examples quoted one can see that the percentage of industrial timber treated in tropical countries is much lower than the corresponding figure for developed countries, while in fact the opposite should be the case.
Another important material which has not been taken into account here is bamboo. Bamboo is a widely used raw material for housing. Id Asia and the Far East, it is estimated that the potential bamboo production is 30 to 40 million cubic metres: per year, of which less than one quarter is utilized. Bamboo has generally been regarded as a nondurable material lasting from 3 to 5 years at the most, but trials have proved that properly impregnated bamboo may last 15 years or more after treatment, at a cost reported to be about 30 percent of its value.
FOREST MANAGEMENT
Wood preservation constitutes an important factor in forest conservation. The extended serviceable life of the timber in particular reduces very considerably the drain on the forest resources. Preservation also makes forest operations more economic by opening up markets for thinnings and species for which there would otherwise be no demand. Utilization of large numbers of suitably treated indigenous species is an essential factor in making hitherto unutilized forest areas economically viable. This is why promotion of wood preservation should be a subject of interest not only to wood industrialists but also to forest services.
EXPORT OF FOREST PRODUCTS
Another field in which wood preservation can be of particular importance is in the export of forest products. The main line of effort should be to reserve for export markets the most durable and precious species and replace them on the local market by less durable but properly treated timbers.
Unfortunately, this is not always the case. In Indonesia, for example, untreated teak sleepers are used on the local market instead of treated, but less durable, species. There are, of course, many specific reasons for this situation but the basic fact remains that in the present economic situation in Indonesia such an important potential export commodity as teak should be replaced on the internal market by less valuable, less durable, but properly treated species.
In many cases, preservation of wood products may be a necessary condition for the successful promotion of their export. For a number of years timbers from Malaya have been immunized before they were exported to New South Wales and Queensland. It is a requirement under a by-law of these two States that imported timbers should be immunized against borer attack. This by-law does not apply in South Australia or Victoria; however, in view of the increasing number of complaints about timber infested with borers, treatment will become necessary if this export market is to be retained.
There are numerous examples of losses in the export value of timber on account of "staining" through lack of preservative treatment, even though the strength properties of the timber were not reduced.
UTILIZATION OF SECONDARY SPECIES
The importance of reserving durable species for export markets and replacing them by treated less durable species has already been emphasized. In many countries, however, such replacement becomes a sheer necessity because of the alarming ratio at which resources of naturally durable timbers are diminishing.
In the Philippines, the national railways depend on such durable species as ipil, molave and yakal for sleepers, but as reserves of these species become more and more depleted their replacement by treated secondary species - if not by other materials than wood - looks like being the only solution. A similar situation exists in Malaysia, where diminishing supplies of heavy sap-free hardwoods for sleepers and construction timber make their replacement by preservative treated medium-density hardwoods essential. In Thailand, the decreasing supply of durable species is causing a steady rise in prices which is likely to act as an important stimulus for the preservation of secondary species.
HOUSING
A further important field in the national economy where wood preservation could - and indeed should - play an outstanding role is housing. As is well known, in many tropical countries the housing situation, is critical, and this makes prefabricated houses a subject of special interest. Local scarcity of treated wood, however, has been a considerable obstacle to the more extensive use of timber for housing in the tropics.
In Nigeria, where the cost of timber is much lower than in Europe, builders are said to show a preference for steel and concrete because of lack of properly treated timber (and this is one of the reasons why the consumption of sawnwood in that country is extremely low: 6 cubic metres per 1000 inhabitants compared with 180 cubic metres in Europe).
If it is remembered that an average of 60 to 70 percent of sawnwood, wood used in the round and wood-based panels finds its final outlet in housing and building, and that in the tropics practically all the wood used for these purposes should be treated, the vital importance of wood preservation is unmistakably clear.
Here it should be mentioned that FAO, in cooperation with the International Union of Forest Research Organizations (IUFRO) and the United Nations Center for Housing, Building and Planning, is organizing a World Consultation on Wood in Housing and Structures, with particular emphasis on low-cost housing. An important part of the deliberations at this consultation will be devoted to problems related to wood preservation.
To sum up - the need for and significance of wood preservation in tropical countries are emphasized by the following established facts.
1. The great variety of wood-destroying insects and fungi in tropical countries constitutes a much greater danger for timber used in such areas than it does in the case of timber used elsewhere in the world.2. High temperature and high atmospheric humidity, together with the extraordinarily large number of nondurable wood species, render timber in the tropics particularly vulnerable to decomposition.
3. Consumption of sawnwood and wood used in the round is expected to rise considerably in the tropics during the period from 1961 to 1975. The expected growth rate (70 percent) is likely to be more than three times higher there than in the rest of the world.
4. The value of timber used in tropical countries as sawnwood and roundwood amounted to approximately $2100 million in 1966. A considerable proportion of this value could be saved annually through expanding the preservation treatment of wood.
5. The average cost of preservation may amount to 25 to 35 percent of the initial value of the wood and ensures a service life of not less than three to five times that of untreated timber.
The average investment costs for establishing a pressure-treatment plant are low ($5 per cubic metre per year); this makes it possible to establish the necessary capacities with a comparatively small capital expenditure and over a short period of time.
6. Every dollar spent on wood preservation gives in return more than 10 times that value in savings by prolonging the natural durability and hence the service life of the wood.
7. Wood preservation makes it possible to reserve precious durable species for export markets by replacing them on local markets with less durable but properly treated timbers. It is also a necessary condition for export trade in many wood products which are vulnerable to damage by fungi or insects.
8. In many countries where naturally durable species are nearing depletion, utilization of properly treated secondary species constitutes the only way in which the utilization of wood in most of its applications can be maintained.
9. Utilization of secondary species as a result of preservative treatment makes forest operations more intensive and economical. - It also constitutes an important factor in forest-conservation and in the expansion of forest operations into areas which have formerly been economically inaccessible.
10. Of the world total of industrial wood, 60 to 70 percent finds its outlet in housing and other buildings.
This gives particular importance to wood preservation in tropical countries, where all the semidurable and nondurable timbers used for this purpose should be treated.
Finally, it is not possible to talk about the importance of wood preservation without at the same time mentioning the need for maintaining and developing confidence in the preservative treatment of wood.
Numerous examples could be quoted of unfortunate experiences with poorly treated timbers in tropical countries and experiences of this kind have been one of the major obstacles to further development of the wood preservation industry. It is easy to state that the effectiveness of wood preservation depends on the depth of penetration and retention of preservatives, but in practice no two species of timber have the same properties, nor are two pieces of the same species exactly alike. Hence, the response of wood to treatment with preservatives may vary considerably. It is the wood preservation industry's duty to ensure the full effectiveness of treatment operations. But it is also the responsibility of forest services and other authorities concerned to keep a watchful eye on preservation activities so that failures can be prevented and confidence maintained or restored. Only then will it be possible to take steps toward the expansion of the wood preservation industry.
In this connection, it can be said that one of the most urgent tasks should be to convince the authorities concerned in each country of the numerous advantages of wood preservation, using the language of economic facts and figures. In other words, general considerations will have to be translated into a concrete language of facts and figures relating to a given country. The figures given here are of necessity rough estimates. Concrete figures for individual countries need to be worked out on the spot from practical experience. That, and that alone, is the only language which will convince industries and government authorities of the real importance and true value of wood preservation and the urgent need for its rightful and proper expansion.
