Table Of ContentPRODUCTION, MARKETING AND USE OF FINGER-JOINTED
SAWNWOOD
FORESTRY SCIENCES
Also in this series:
Oldeman RAA, et al. eds: Tropical Hardwood Utilization: Practice and
Prospects. 1982. ISBN 90-247-2581-X
In preparation:
Baas P: New Perspective in Wood Anatomy
Bonga 1M and Durzan D1 eds: Tissue Culture in Forestry
Chandler CC, Cheney P and Williams DF eds: Fire in Forest
Gordon 1C and Wheeler CT eds: Biologocal Nitrogen Fixation in Forest
Ecosystems: Foundation and Applications
Hummel FC ed: Forestry Policy
Madgwick HAl: Forest Biomass
Nemeth MV: The Virus - Mycoplasma and Rickettsia Disease of Fruit Trees
Powers RF and Miller HG eds: Applied Aspects of Forest Tree Nutrition
Powers RF and Miller HG eds: Basic Aspects of Forest Tree Nutrition
Rajagopal R: Information Analysis for Resource Management
Van Nao T, ECE/FAOAgriculture and Timber Division eds: Forest Fire
Prevention and Control
Series ISBN 90-247-2447-3
PRODUCTION, MARKETING
AND USE OF
FINGER-JOINTED
SAWNWOOD
Proceedings of an International Seminar organized by
the Timber Committee of the
United Nations Economic Commission for Europe
Held at Hamar, Norway, at the invitation of the Government of Norway,
15 to 19 September 1980
edited by
C.F.L. PRINS
1982
MARTINUS NIJHOF / DR.W. JUNK PUBLISHERS
THE HAGUE / BOSTON / LONDON
for
THE UNITED NATIONS
Distributors
for the United States and Canada
Kluwer Boston, Inc.
190 Old Derby Street
Hingham, MA 02043
USA
for all other countries
Kluwer Academic Publishers Group
Distribution Center
P.O. Box 322
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Library of Congress Cataloging--4n Publil'ation nata
Main entry under title:
Production, marketing and use of finger-jointed
sa WI"MOod •
(Forestry sciences)
Includes indeX".
1. Woodworking industries--Congresses.
2. Timber joints--Congresses. I. Prins, C. F. L.
II. United Nations. Economic Commission for
Europe. Timber Committee. III. Series.
TSB02.P76 674'.43 Bl-22525
ISBN 978-94-015-3769-8 AACR2
ISBN 978-94-015-3769-8 ISBN 978-94-015-3859-6 (eBook)
DOI 10.1007/978-94-015-3859-6
Published for the United Nations by Martinus Nijhoff / Dr.W. Junk Publishers
Copyright © 1982 by The United Nations, New York and Martinus Nijhoff / Dr. W. Junk
Publishers, The Hague.
Soficover reprint oft he hardcover 1st edition 1982
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted in any form or by any means, mechanical, photocopying, recording, or otherwise,
without the prior written permission of the publishers,
Martinus Nijhoff / Dr. W. Junk Publishers, P.G.Box 566, 2501 CN The Hague, The Netherlands.
v
Preface
The seminar on the production, marketing and use of finger-jointed
sawnwood was held in Hamar from 15 to 19 September 1980 at the invitation of
the Government of Norwa;y. It was organized under the auspices of the Timber
Committee, a subsidiary body of the United Nations Economic Commission for
Europe (ECE) in Geneva, Switzerland.
Participants represented the ECE member countries of Belgium, Canada,
Denmark, Finland, France, Federal Republic of Germany, Hungary, Ireland,
Italy, Netherlands, Norwa;y, Poland, Sweden, Union of Soviet Socialist Republics,
United Kingdom of Great Britain and Northern Ireland and United States of
America. Observers from Australia and South Africa attended as well, and the
United Nations Organization for Industrial Development (UNIDO) was represented.
Mr.R. Birkeland of Norwa;y was elected Chainnan, and Mr. V. Turushev of the USSR
Vice-Chainnan.
During the seminar, study visits were arranged for participants:
to Berger Langmoen A. S., Brumunddal, whi ch produces sawnwood, planed wood,
wooden packaging, building components using finger-jointed timber, parquet
flooring and fibreboard;
to the Moelven Group, Moelv, which produces modular houses and other types
of timber-framed buildings and building panels, sawnwood, glue-laminated
products, skis, etc., as well as a number of types of mechanical equipment and
vehicles. Finger-jointed sawnwood is produced and extensively used in its
timber-based products;
to the Forest Museum, Elverum;
to Br~drene Hetland, at whose warehouse in Skarnes components and elements
for prefabricated buildings are stored and prepared for despatch;
to the Norwegiaa Institute of Wood Working and Wood Technology (NTI),Oslo,
a main objective of which is to be a research centre for the Norwegian saw
milling industry, covering amongst other subjects, sawmilling and planing
operations, wood drying, construction in wood, wood and fire, wood protection,
gluing, work environment, standardization of quality control.
The participants expressed their deep appreciation to the host country and
the organizations concerned for arranging these very useful visits.
The "Report of the seminar" reproduced hereafter, contains a summary of
the discussions which took place on each item of the agenda as well as the
conclusions and recommendations of the seminar. These conclusions and
recommendations were endorsed by the Timber Committee at its session in October
1980.
Three types of documents were available to the seminar participants :
basic papers with summaries in the three official languages (English, French
and Russian), voluntary papers (in one language only) and country monographs
presented by three delegations. As this is essentially a monolingual
publication, only the texts in English are presented here, with the exception
of the full text of the only basic paper in French, that of Mr.P. Lombard,
which is accompanied by a summary in English.
The opinioDl,expressed in the papers are those of the authors and do not
necessarily correspond either to the official views of authors' Governments
or to those of the Secretariat. The Secretariat cannot accept responsibility
for the accuracy of any statistics or statements included in these proceedings,
which appear in the form in which they were presented to the symposium with
minor editorial changes.
VII
TABLE OF CONTENTS
Preface
Report of the seminar 1
11
Papers and Proceedings
Background Papers
Production, marketing and use of finger-jointed 7
sawnwood:
An oven,iew
K. M¢rkved (Norway)
List of words and definitions (~~lish/French) 14
Marketing and applications
(a) 11arketing
11arketing finger-jointed timber 23
J. Baird (United Kingdom)
Marketing structural finger-jointed sawn l~mber 29
in North America (voluntary paper)
L. F. Huettl (Canada)
(b) Structural applications
Research into and experience of the use of 35
finger-joints in timber structures in
Czechoslovakia
P. Dutko, S. Steller and
B. Kozelouh (Czechoslovakia)
Structural finger-joints 48
D. Lamb-Shine and R.W. Wands (United Kingdom)
The structural use of finger-jointing 55
J.G. Sunley (United Kingdom)
Use of finger-jointed timber in housing 60
N.r. Bovim (Norway)
(c) Non-structural applications
Finger-jointing in non-load-bearing applications 73
(FUll paper in French, summary in English)
P. Lombard (France)
17
Most of the papers presented to the seminar as basic papers are
accompanied by a short summary. Voluntary papers have no summary.
Voluntary papers are indicated in the table of contents.
VIII
Non-structural application of finger-jointed timber
E. RaImes (Norwa;y)
Applied research for mini-finger-joint 90
L. Bonkowski and L. Trinchera (USA)
Quality controls, standardization and harmonization
International acceptance of manufacture, marking and 106
control of finger-jointed structural timber
B. Noren (Sweden)
Proof loaded finger-joints for structural glued 115
laminated timber
R.E. Eby (USA)
Some views on quality control 121
J.P. van Zyl and I.S.J. Burger (South Africa)
Structural finger-jointing criteria and performance 141
(Voluntary paper)
R.E. Eby (USA)
Properties and influences
P.be influence of production conditions on the 154
strength of finger-joints
E. Ralmes (Norwa;r)
The effect of geometry on the performance of 169
structural finger-joints
R.W. J.okerst (USA)
End pressure for finger-jointing 181
R. Juvonen (Finland)
Strength of finger-joints 190
H.J. Larsen (Denmark)
Mini-finger-joints, 7.5 mm long, according to 202
DIN 68140. Compression and tension stresses
~arallel to the fain. Deformation analysis
tVoluntary paper
F. Paganini (Italy)
Test methods
Testing of finger-joints in structural timber for 205
quality control
B. Hajek (Sweden)
Trouble-shooting in finger-jointing 225
(Voluntary paper)
I. Larsen (Norwa;r)
IX
Production
Production of finger-jointed timber, especially 226
in the Federal Republic of Germany
H. Kolb (Federal Republic of Germany)
Adhesives used in South Africa to finger-joint
structural timber
H. Scharfetter and A. Pizzi (South Africa)
The production of finger-joints in the Netherlands 246
G.N. Ruysch (Netherlands)
Finger-jointing sawn lumber: Techniques and 254
product requirements
M.N. Caroll (Canada)
Production and economics of finger-jointing
structural timber in Sweden
R. Palm (Sweden)
Is economic finger-jointing for production of 270
load-bearing structural timbers possible?
(Voluntary paper)
C. Overlack (Federal Republic of Germany)
Country reports
- Finger-jointing techniques in Hungary 275
- Development of the production and application 276
of finger-jointing of coniferous sawn timber
in Poland
- The use of finger-jointed timber in the 279
United Kingdom
- I -
REPORT OF THE SEMINAR
Marketing and application (Item 3 of the agenda)
Discussion leader: Mr. J-. Sunley (United Kingdom)
(a) Marketing
The seminar agreed that there was considerable potential for expansion
in the use of finger-jointed sawnwood in all countries. To realize this
potential, good marketing, aimed at gaining acceptance for a product, the
characteristics of which were unfamiliar to many users, was essential. One
necessary element of such a marketing strategy would be the clear and open
presentation to buyers of finger-jointed timber's properties and of the quality
control procedures used to ensure that these properties were consistently
maintained. Technically sound and widely recognized standards for finger-jointed
sawrrirood should also play an important role in gaining acceptance for the
product. Finger-jointing also made it possible to offer the sawnwood buyer at
a reasonable price exactly the lengths he required, thus avoiding wastage,
notably on the construction site, as well as long lengths which were difficult
or expensive to supply in unjointed timber.
(b) Structural timber
The seminar reviewed the wide range of structural applications for finger
jointed sawnwood. In a few cases, notably where failure of a single joint could
cause structural damage, the use of finger-joints was restricted in some
countries, but in general finger-jointed timber could be used in the same
applications as unjointed timber. In glulam members, finger-joints made it
possible to cover wider spans than could be covered by unjointed timber members.
In all structural applications, the designer needed firm assurances that the
joint would satisfy certain minimum requirements. These assurances are provided
by close surveillance of the finger-jointing process to ensure that the variables
involved are under close control and that the joint strength is in balance with
the strength of the grade being jointed. The control of joint strength and the
accuracy of stress grading are equally significant.
(c) Non-structural applications
There were also many non-structural applications for finger-joints which
were reviewed by the seminar. These included joints in furniture, internal
and external joinery, agricultural buildings and more specialized applications
such as pencil slats. The seminar considered that there was a possibility of
developing further types of non-structural applications for finger-jointed
timber. In these uses, qualities other than strength, notably appearance
(glue colour), assumed great importance. Equipment now existed for the colour
sorting of pieces to be joined so that excessive colour contrast at the joint
could be avoided.
Quality controls, standardization and harmonization (Item 4 of the agenda)
Discussion leader: Mr. H.J. Larsen (Denmark)
Strict quality control, both internal (by the manufacturer) and external
(e.g. by a standards institution), was essential to gain acceptance for finger
jointed timber and to maintain confidence in the product. Only a few joint
failures, which better quality control might have prevented, could compromise
