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International Biodeterioration & Biodegradation xxx (2013) 1e6
Contents lists available at ScienceDirect
International Biodeterioration & Biodegradation
j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / i b i o d
Effectiveness of on-site remediation treatments for framing timber
Tripti Singh a, *, Dave Page a, Adrian Bennett b
a Scion, Private Bag 3020, Rotorua, New Zealand
b Ministry of Business Innovation and Employment, Wellington, New Zealand
a r t i c l e i n f o
a b s t r a c t
Article history:
Weathertightness failures in New Zealand buildings due to the combined effects of cladding choices,
Received 26 March 2013
design and construction faults and the use of untreated framing timber has led to the so called ‘leaky
Received in revised form
building syndrome’. The latest estimated cost of the leaky building crisis in New Zealand is about NZ$11
16 August 2013
billion.
Accepted 5 September 2013
This research was conducted to provide a better understanding of the options of using in-situ pre-
Available online xxx
servative treatments for controlling incipient and early decay in framing timber which is still structurally
sound when remediating leaky buildings.
Keywords:
The research approach involved taking untreated radiata pine sapwood, pre-infecting it with common
Boron
Copper naphthenate
brown rot fungi either Oligoporus placenta or Gloeophyllum sepiarium, applying a brush-on timber
Leaky building
treatment of either boron-glycol or copper naphthenate to one or more sides, and then maintaining the
Remedial treatment
samples at elevated moisture conditions. After speciﬁc durations, the samples were examined and tested
Wood biodeterioration
to determine the effectiveness of the treatments in slowing down or preventing decay from progressing
using measurement of stiffness (express as modulus of elasticity) and decay (expressed as an index of
condition).
Assessment conﬁrmed that the performances of both preservatives improved as more sides of timber
were treated. However, there were signiﬁcant differences in efﬁcacy of both preservatives. Boron applied
to three or four side appears to have been effective in preventing decay from progressing. Copper
naphthenate at the concentration used has not been successful in preventing decay, regardless of the
number of faces treated.
The treatment retention in samples treated with boron on three or four sides was about 0.4% (BAE w/
w) and 0.65% (BAE w/w) respectively. This is close to or above the cross-sectional retention required by
New Zealand H1.2 (interior framing) speciﬁcation.
Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction
dried radiata pine house framing when water penetrated the
exterior cladding (leaky buildings) became prominent in the late
Weathertightness failures (Murphy, 2001) in New Zealand
1990’s (Hardie, 1997; Hunn et al., 2002). While building regulations
buildings resulting in decay of timber framing have caused great
requiring the preservative treatment of radiata pine framing were
concern (Hunn et al., 2002; Cooney, 2009). Most timber used for
re-introduced in 2003, a large number of deteriorating buildings
house framing in New Zealand is radiata pine. Up until 1992, the
constructed in the previous decade continued to require extensive
framing timber was always treated with boron. From the early
repairs (Groufsky, 2008). This generally includes re-cladding and
1990s, along with boron, a range of alternative timber framing
replacement of unsound framing. Where framing appeared to be
treatment options became available including solvent based pre-
still sound, it was allowed to dry out and some type of brush-on
servatives such as copper naphthenate, tri-n butyltin oxide and
remedial treatment was applied before new cladding was
others (NZS 3640, 2003). Due to changes in the building code, from
installed. The efﬁcacy of these brush-on treatments in this type of
1995 to April 2004, homes were often built with untreated kiln-
situation had not been widely tested and there were many situa-
dried radiata pine. Problems with the decay of untreated, kiln-
tions within buildings where the in-situ application of preservative
could only reach one or two surfaces of the components (Cooney,
2009). There was also some uncertainty about the identiﬁcation
of “incipient decay” (Winandy and Morrell, 1993) and whether
* Corresponding author. Tel.: þ64 7 343 5329; fax: þ64 7 343 5507.
E-mail address: [email address] (T. Singh).
apparently sound timber adjacent to decaying timber could be
0964-8305/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.ibiod.2013.09.003
Please cite this article in press as: Singh, T., et al., Effectiveness of on-site remediation treatments for framing timber, International
Biodeterioration & Biodegradation (2013), http://dx.doi.org/10.1016/j.ibiod.2013.09.003

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T. Singh et al. / International Biodeterioration & Biodegradation xxx (2013) 1e6
Table 1
Sample treatment and exposure groups.
Group code
Exposure
Number
Pre-decay
Number of edges
Number of faces
type
of samples/group
period (weeks)
treated
treated
Copper naphthenate treated
Boron treated
C61H
B61H
HMC
20
8
1
e
C62H
B62H
HMC
20
8
2
e
C63H
B63H
HMC
20
8
2
1
C64H
B64H
HMC
20
8
2
2
C31H
B31H
HMC
20
4
1
e
C32H
B32H
HMC
20
4
2
e
C33H
B33H
HMC
20
4
2
1
C34H
B34H
HMC
20
4
2
2
C62L
B62L
LMC
10
12
2
e
C64L
B64L
LMC
10
12
2
2
C32L
B32L
LMC
10
7
2
e
C34L
B34L
LMC
10
7
2
2
B3H
HMC
20
4
H1.2 treated
B3L
LMC
10
7
H1.2 treated
U3H (untreated)
HMC
20
4
e
e
U3L (untreated)
LMC
10
7
e
e
UMH (untreated)
HMC
20
Nil
e
e
UML (untreated)
LMC
10
Nil
e
e
successfully protected by brush-on remedial treatments. The pos-
selected; Oligoporus placenta (Fries 1865) and Gloeophyllum sepia-
sibility that minor decay in timber could be stopped by brush-on
rium (Wulf.: Fr.) Karst.
treatments was also questioned.
Small 35 mm square blocks of radiata pine sapwood that had
A number of commonly used timber remedial treatment pre-
been pre-infected with selected brown rot decay fungi (Hedley
servatives are readily available (Newbill and Morrell, 1993; Ridout,
et al., 2009), either O. placenta to be exposed in wetter high mois-
2000; Wilkes and Page, 2004). Two of the commonly used products
ture content (HMC) conditions (>30% MC) or G. sepiarium for
include a copper naphthenate concentrate that is diluted with a
samples that were to be exposed in drier, low moisture content
light organic solvent such as kerosene or white spirits (Morrell
(LMC) conditions (25e27% MC), were attached near the centre of
et al., 1996; Richardson, 1997) and the other one is a boron/glycol
each sample on one edge. The samples were stacked in sealed
solution (Edlund et al., 1983; Vinden et al., 1990). Zinc naphthenate
plastic tanks with 20 mm thick plastic ﬁllets separating the layers.
concentrate is also being used for non-commercial applications but
In each tank there was a small amount of water in the bottom and a
is regarded as a less effective fungicide than copper naphthenate
wet foam plastic blanket in the top to maintain high humidity. The
(Wilkes and Page, 2004).
tanks were kept in a laboratory where the ambient temperature
This research was conducted to determine:
was 15e20 C. The intention was to pre-decay samples for two
periods, the ﬁrst just sufﬁcient to produce “incipient decay” in the
Whether copper naphthenate or boron brush-on treatments
samples, the second to produce more established decay. Half of the
would be effective in controlling decay on framing that already
HMC samples were left in the pre-decay tanks for four weeks, the
contained incipient or lightly established decay.
remainder for eight weeks. The G. sepiarium decay blocks were
The number of surfaces of a partially degraded component that
slower to develop on the LMC samples and half of these samples
needed to be coated to control decay.
were in the tanks for seven weeks, the remainder for twelve weeks.
The extent of decay that could be present in a component before
The commercially treated samples were kept in the tanks for four
it was signiﬁcantly weakened.
weeks, (HMC exposure samples) or seven weeks (LMC exposure
samples).
2. Materials and method
2.3. Sample assessment before remedial treatment
2.1. Timber samples
At the end of the decay exposure period (as mentioned above),
once the samples had reached the required degree of decay, they
Radiata pine sapwood framing (SG 8), kiln dried and planer
were removed from the tanks, reweighed, assessed mycelium
gauged to 90 mm 45 mm, was cut into 950 mm long samples.
spread and decay using the American Standards rating systems
Samples were sealed at both ends with epoxy paint (Altex Altra-
based on AWPA Standard E7-1993 (AWPA, 1999) shown below.
build 536). A set of samples that had been commercially treated
Decay Ratings
with boron to the H1.2 speciﬁcation were also included. The sam-
ples were all weighed and their moisture content was determined
10 ¼ No decay.
by oven drying biscuits cut from the samples. An oven-dry weight
T ¼ Trace, discolouration or softening, not positively identiﬁed
was calculated for each sample using this moisture content data. All
as decay.
samples were soaked in water for 80 min to achieve a moisture
9 ¼ First stages of decay or damage up to 3% of cross-section.
content above 30%.
8 ¼ Lightly established decay, 3e10% of cross-section.
7 ¼ Well established decay, 10e30% of cross section.
2.2. Fungal pre-infection
6 ¼ Deep established decay, 30e50% of cross section.
4 ¼ Severe decay, nearing failure, more than 50% of the cross
Two brown rot fungi commonly found causing decay of un-
section.
treated Pinus radiata D. Don, in leaky buildings in New Zealand was
0 ¼ Failed.
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3
Table 2
and kerosene (1.2% Cu w/v) or a boric acid/borax mixture in
Preservative application rates and retention.
monoethylene glycol (20% Boric Acid Equivalent).
Treatment
Copper naphthenate
Boron
The sample infected with O. placenta, the treatment was applied
to either one edge, two edges, two edges and a face or four sides.
Application Retention
Application Retention
rate (g/m2)
(g/100 g Cu)
rate (g/m2)
(g/100 g BAE)
For samples infected with G. sepiarium, the treatment was applied
to either two edges or four sides.
HMC samples
One edge
149
0.006 0.001a 182
0.107 0.019
Two edges
140
0.011 0.003
184
0.220 0.033
2.5. Sample exposure and assessment
One face, two edges 188
0.028 0.006
182
0.426 0.046
Four sides
220
0.044 0.011
211
0.650 0.083
LMC samples
After the preservative treatment, the samples were re-wetted
Two edges
168
0.013 0.003
179
0.215 0.015
and placed in tanks approximately 1 m long, 0.8 m wide and
Four sides
241
0.048 0.002
214
0.693 0.055
0.8 m deep with a tight ﬁtting lid and a drain in the bottom.
a Standard deviation.
Samples infected with O. placenta, were kept at 100% relative hu-
midity (RH) and were intermittently wetted to maintain high
moisture content (HMC), greater than 30% moisture content.
Decay feeder blocks were removed and external decay myce-
Samples infected with G. sepiarium were kept at 95% RH to maintain
lium was cleaned off. Samples were then tested for deﬂection as a
low moisture content (LMC) samples at 25e27% moisture content.
plank in a mechanical strength testing machine to assess the
Samples were allocated randomly to the groups shown in Table 1.
stiffness. The machine used for stiffness testing was a custom-built,
Control samples of untreated P. radiata that had not been
three point, deﬂection measuring machine which gradually applies
infected with decay fungi were placed in both the LMC and HMC
a 872 N load centrally to the sample over a 914 mm span. After
tanks.
stiffness measurement samples were placed in ﬁlleted stacks in the
The samples were evaluated every two months for the ﬁrst
laboratory. Large fans were used to blow air through the stacks until
eighteen months of the study, and after that, at six monthly in-
the sample moisture content was below 20%.
tervals. For all assessments during the trial, samples were removed
from exposure tanks, weighed and measured using the same MOE
2.4. Preservative treatment of samples
apparatus as previously. The assessments measured deﬂection,
moisture content, and amount of decay. The surfaces of each
After two weeks of drying, two coats of remedial treatment
sample were tested with a blunt probe to determine the extent of
products were applied by brush, either 50/50 copper naphthenate
decay based on AWPA Standard E7-1993 (AWPA, 1999). Moisture
Table 3
Annual mycelium spread, index of condition and deﬂection.
Group
Mycelium spread rating
Index of conditiona
Deﬂection (mm)
code
56-wk
108-wk
159-wk
56-wk
108-wk
159-wk
56-wk
108-wk
159-wk
High moisture content groups (159 weeks)
C61H
3.4
4.2
5.3
7.6
6.5(1)c
4.5(3)
2.36
3.04
3.92
C62H
3.6
4.2
5.4
7.8
6.5(1)
4.3(3)
2.46
2.94
4.26
C63H
3.1
3.2
4.3
8.0
7.6
6.1(2)
2.16
2.31
3.07
C64H
1.1
1.9
2.4
8.0
7.8
7.6
2.16
2.22
2.30
B61H
3.6
4.1
4.7
7.3
6.5
5.6
2.31
2.92
3.25
B62H
1.5
1.5
1.7
8.0
8.0
8.3
2.38
2.40
2.44
B63H
1.2
1.1
1.1
8.3
8.2
8.6
2.13
2.16
2.20
B64H
1.0
1.0
1.0
8.2
8.1
8.5
2.19
2.24
2.25
C31H
3.3
4.3
5.1
7.6
6.9
4.7(4)
2.46
2.93
4.31
C32H
3.2
4.2
5.5
7.9(1)
6.3(1)
3.5(8)
2.50
3.06
5.20
C33H
2.1
3.2
4.6
8.7
7.8
6.5
2.47
2.64
3.11
C34H
1.3
2.7
3.8
8.8
8.3
6.7(2)
2.29
2.46
3.15
B31H
4.1
4.5
5.0
6.9
6.0
4.6(2)
2.69
3.62
4.26
B32H
1.7
1.6
1.8
9.0
8.5
8.9
2.30
2.32
2.37
B33H
1.0
1.0
1.0
9.5
9.2
9.8
2.33
2.32
2.36
B34H
1.0
1.0
1.3
9.3
8.9
9.4
2.18
2.19
2.24
B3Hb
1.0
1.0
1.0
10.0
10.0
10.0
3.88
3.88
3.93
U3H
3.9
4.5
5.2
7.2
5.1(4)
2.9(10)
2.66
4.11
5.76
UMH
2.7
2.4
2.9
9.4
8.5
7.7(2)
2.28
2.39
3.01
Low moisture content groups (157 weeks)
C62L
3.1
3.8
3.4
6.4(1)
5.4(2)
4.7(3)
3.19
3.75
4.21
C64L
1.3
1.6
1.8
7.9
7.3
7.7
2.35
2.52
2.58
B62L
2.4
2.8
3.2
7.7
7.5
7.3
2.55
2.61
2.71
B64L
1.0
1.0
1.0
8.0
8.0
8.2
2.29
2.39
2.36
C32L
2.2
2.9
3.3
8.1
7.3
6.1(1)
2.22
3.15
3.29
C34L
1.0
1.1
1.0
8.2
8.0
8.1
2.08
2.21
2.18
B32L
1.1
1.6
1.7
8.3
8.1
8.3
2.09
2.18
2.18
B34L
1.0
1.0
1.0
8.2
8.4
8.4
2.30
2.39
2.36
B3Lb
1.1
1.0
1.0
10.0
10.0
10.0
3.73
3.84
3.83
U3L
2.5
3.4
3.9
6.3(1)
5.0(3)
4.4(3)
3.37
4.21
4.18
UML
1.7
1.9
2.2
9.6
8.1(1)
7.5(1)
2.25
2.99
3.02
a Index of condition is the average decay rating for all of the samples in a group.
b This group was framing grade timber, all other groups were clears grade sapwood.
c The number of samples in the group that had failed (in parenthesis).
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4
T. Singh et al. / International Biodeterioration & Biodegradation xxx (2013) 1e6
Fig. 2. a. The mean index of condition for Copper naphthenate treated. b. The mean
index of condition for Boron treated samples.
Fig. 1. a. The mean modulus of elasticity (MOE) for copper naphthenate treated
samples. b. The mean modulus of elasticity (MOE) for boron treated samples.
Differences were considered to be signiﬁcant at P 0.05.
content calculations were based on changes in sample weight.
Deﬂection as a plank under a constant load was measured. Modulus
of Elasticity (MOE) for each sample was calculated using sample
3. Results
cross-section and deﬂection measurements.
After assessment the samples were returned to their original
3.1. Timber treatment retention levels before exposure
exposure positions. The HMC samples were sprayed with water as
they were re-installed but the LMC samples were protected from
The application of two coats of both preservatives solutions
wetting.
resulted in appreciable uptake of treatment (Table 2). For boron
After the 159-week, ﬁnal assessment, ﬁve samples for each
glycol, the average coverage rate was 190 g/m3, whereas for copper
preservative type, that had been treated on various sides, were
naphthenate the average coverage rate for all samples was 180 g/
removed from each of the HMC and the LMC exposure groups
m3.
randomly. Biscuits were removed from each sample for chemical
Preservative uptake data indicated that the preservative reten-
analysis and for reagent testing to determine the penetration of the
tion in all of the copper naphthenate treated samples was well
preservative and the extent of decay.
below the minimum of 0.10% (w/w Cu) required by the H3.2
For decay analysis, one set of samples from each group was
speciﬁcation in NZS 3640:2003 (Chemical Preservation of Round
sprayed with methyl orange reagent which turns a pink-red colour
and Sawn Timber). Preservative retentions in samples treated with
where there is an active decay (Ellis, 1961). Samples were matched
boron on three or four sides were generally above the minimum
to analyses of preservative distribution. For copper naphthenate,
0.4% BAE requirement of the H1.2 speciﬁcation (Table 2). The var-
samples were sprayed with rubeanic acid reagent which turns
iations in the retention rates were relatively small particularly
blue-black in the presence of copper (Cummins, 1966). For boron,
given the variable nature of timber. The standard deviation for
samples were sprayed with tumeric reagent which turns red in the
boron glycol retention was in the range of 10e18% of mean. For
presence of boron (Robinson, 1939).
copper naphthenate, it was higher at 22e28% of mean.
2.6. Statistical analysis
3.2. Moisture content
A two-way analysis of variance was conducted and least sig-
The moisture content of the LMC samples remained relatively
niﬁcant difference tests were used to compare differences between
constant through the exposure period, generally close to 25%. The
the efﬁcacy of two preservatives and also the differences between
average moisture content of the HMC samples generally stayed
treating various sides of framing timber for each preservative.
above 30% throughout the exposure period.
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5
3.3. Performance of treated samples
high temperatures with lower moisture content (Gilbertson, 1981;
Eslyn, 1986). Previous research has shown that for the radiata pine,
Mycelium became established on the untreated surfaces of
the minimum wood moisture content for decay progression on
samples within six months of installation in the exposure stacks.
framing timber inoculated with decay fungi was 24e25% mc (Page
This progressed steadily, particularly on the untreated samples and
et al., 2003). In this study, the targeted moisture content for test
those treated on only one edge. This indicates that drying of sam-
framing samples were achieved in both LMC and HMC tanks
ples after pretreatment infection was not enough to kill the decay.
(Table 3). Given the right substrate for nutrient, decay fungi can
Mycelium development on copper naphthenate treated surfaces in
grow proliﬁcally on wood at ﬁbre saturation point (approximately
the HMC tanks continued throughout the trial.
30% moisture content) (Page et al., 2003).
By comparison there was no decay mycelium on boron treated
This study simulated typical leaky building scenario where
surfaces. On the samples where decay mycelium developed on
wood remains exposed to a humid and wet environment contain-
untreated faces of boron treated samples it began to degenerate
ing active decay fungi. Regardless of the extreme conditions in this
after two years exposure and was largely inactive by the end of the
study, brush-on boron treatment on at least two edges and a face
trial. Decay ratings and deﬂection data are summarised in Table 3.
was able to control decay. However, copper naphthenate has not
As expected, the performances of both preservatives improved as
been successful in preventing decay, regardless of the number of
more sides of the timber were treated (P 0.05). This is reﬂected in
faces treated. The treatment retention in samples treated with
both the measurement of stiffness (expressed as MOE; Fig. 1a and b)
boron on three or four sides was about 0.04% (BAE w/w) and 0.065%
and of decay (expressed as index of condition; Fig. 2a and b). Overall,
(BAE w/w) respectively. This is close to or above the cross-sectional
the boron-glycol treated samples performed signiﬁcantly better
retention required to inhibit fungal growth on framing (H1.2
(P 0.05) than those treated with copper naphthenate (Figs.1 and 2).
speciﬁcation; NZS 3640). The copper retention for samples treated
Over the test period, decay rating changes followed that same
with copper naphthenate on four sides was on average only 44% of
pattern as changes in deﬂection (Table 3). Decay progressed
the H3.2 requirement (NZS 3640, 2003) and less than would nor-
steadily in the samples treated with copper naphthenate on one or
mally be required for decay prevention.
two edges (C1 or C2; Fig. 2a) and those treated with boron on one
In copper naphthenate treated samples, preservative penetra-
edge (B1; Fig. 2b). There was very little change in the other boron
tion was generally limited to a 5e10 mm envelope around the
treated groups (P 0.05).
outside. Preservative retention and distribution did not change
Noticeable deﬂection increases and changes in MOE have
during the exposure period. In samples treated with boron, some
generally been restricted to those samples which contained
preservative was lost during wetting after treatment but the
moderate-severe decay (ratings 6 or lower).
remaining preservative distributed through the sample cross sec-
tion, including in samples where the moisture content was below
3.4. Preservative retention and internal decay at ﬁnal assessment
30%. Hence the ability of boron to diffuse in presence of moisture
contributed to preventing internal decay. Results of this study are in
The analytical results showed that there was no signiﬁcant loss
agreement with previous studies where when boron is not applied
of copper naphthenate over the exposure period whereas preser-
in whole cross-sections, it re-distributes by diffusion if sufﬁcient
vative retention in the HMC boron treated samples has been
moisture is available (Lloyd et al., 1990; Lebow et al., 2010).
reduced by between 24% and 55% (Appendix, Table 1). The samples
Previous studies have shown that the extensive loss of borates
in the upper layer of the exposure tank (B64H/4) had the highest
occurs only when timber remains wet throughout its cross-section
loss and samples lower in the tank lost progressively less.
for a long period (Obanda et al., 2008). The rate of loss is reduced as
Samples in the LMC stack were not sprayed with water and
retention approaches a level that is insufﬁcient to drive the diffu-
condensation drippage affected only a few in speciﬁc areas of the
sion process and that level is above the toxic limit for decay
stack. Boron loss in the analysed samples varied from 27% to 47%.
(Drysdale, 1994; Lloyd, 1995). The current study showed that the
Figs. 1e3 (in Appendix) shows the spot test results for internal
periodic wetting helped diffusion into the timber without causing
decay and preservative penetration at the ﬁnal assessment. The
serious loss of boron. Preservative retention data showed the boron
distribution of copper in the copper naphthenate treated samples is
is in range of 0.30e0.64% after 3 years exposure. Based on our
relatively close to the surface and shows very little evidence of
previous study, this concentration is more than the minimum toxic
redistribution following treatment. The spot test of boron samples
threshold of boron needed to inhibit brown rot fungi i.e. in the
(Appendix, Fig. 2), treated on three sides from HMC show that the
order of 0.15e0.25% boric acid (Hedley et al., 2009). This indicates
preservative has spread through the whole sample cross-section.
that the boron diffused into the wood in sufﬁcient amounts to
Virtually no internal decay was observed. Fig. 3 (in Appendix)
inhibit or even kill incipient or pockets of decay hence prevented
showed the distribution of boron in LMC samples. Spot test
decay development over the 3 year period.
clearly indicates that boron can penetrate the full cross-section
In NZ, leaky home crisis will be on-going for some time. While
even in samples that were below 30% moisture content and pro-
the building standards have been substantially tightened, several
vided protection against decay.
thousand homes are still awaiting renovation (Price Waterhouse
Coopers, 2009). Any ability to reduce the cost, such as being able
4. Discussions
to treat timber in place rather than having to remove and replace
when not required is beneﬁcial to both building owners and the
The two test brown rot fungi, O. placenta and G. sepiarium used
country in general. A better understanding of the effectiveness of
in this study have most commonly been associated within leaky
remedial treatment is of considerable signiﬁcance for leaky build-
building in NZ (Stahlhut, 2008). Brown rot basidiomycetes fungi is
ing repair. Even a few thousand dollars saved per house would
the most common and destructive type of decay in building around
represent tens of millions of dollars saved overall.
the world (Viitanen and Ritschkoff, 1991; Alfredsen et al., 2005;
Schmidt, 2006). Internal pore fungi such as O. placenta or Antro-
5. Conclusion
dia xantha (Schmidt and Moreth, 2003) prefer high moisture con-
tent and decay actively on timber with moisture above ﬁbre
This study showed that the boron glycol mixture applied to
saturation point (Schmidt, 2007). G. sepiarium grows optimally in
three or four sides of 50 mm thick radiata pine framing at a rate that
Please cite this article in press as: Singh, T., et al., Effectiveness of on-site remediation treatments for framing timber, International
Biodeterioration & Biodegradation (2013), http://dx.doi.org/10.1016/j.ibiod.2013.09.003

6
T. Singh et al. / International Biodeterioration & Biodegradation xxx (2013) 1e6
achieves 0.4% BAE retention will protect against decay develop-
Hunn, D., Bond, I., Kernohan, D., August 2002. Report of the Overview Group on the
ment. Copper naphthenate in kerosene at the applied retention
Weathertigntness of Buildings to the Building Industry Authority. Building In-
dustry Authority, Wellington.
slowed brown rot decay development but did not prevent it. The
Hedley, M.E., Page, D., van der Waals, J., September 2009. Application of borocol
application of higher strength Copper naphthenate solution may
200RH (Framesaver) to control decay on pre-decayed model frame units. Scion
have reduced decay spread on the surface but limited penetration is
Wood Process. Newsl, 1e3.
Lebow, S., Lebow, P., Halverson, S., 2010. Penetration of boron from topically applied
unlikely to prevent internal decay development.
borates solutions. For. Prod. J. 60, 13e22.
Lloyd, J.D., 1995. Leaching of boron wood preservatives e a reappraisal. In: Pro-
ceedings British Wood Preserving and Damp Prooﬁng Association Annual
Acknowledgements
Convention. British Wood Preserving and Damp Prooﬁng Association, Derby,
U.K.
We would like to thank the Ministry of Business Innovation and
Lloyd, J.D., Dickinson, D.J., Murphy, R.J., 1990. The Probable Mechanisms of Action of
Boric Acid and Borates as Wood Preservatives. IRG/WP/1450. International
Employment, Wellington, New Zealand for funding this project.
Research Group on Wood Preservation, Stockholm, Sweden.
Assistance of Jackie van der Waals and Ian Simpson is greatly
Morrell, J.J., Love, C., Freitag, C., 1996. Integrated remedial protection of wood in
appreciated in setting up and assessing at various stages of the trial.
bridges. In: National Conference on Wood Transportation Structure. Depart-
The authors would like to greatly acknowledge late Dr. Mick Hedley
ment of Agriculture, Forest Services, Forest Product Laboratory, Madison, USA,
pp. 445e457.
for initiating this project. His encouragement and intellectual
Murphy, C., 2001. Cladding defects study. Build 66, 8.
support is greatly missed.
Newbill, M.A., Morrell, J.J., 1993. Ability of over-the-counter preservatives to protect
Western wood species from fungal attack. For. Prod. J. 43, 35e40.
Obanda, D.N., Shupe, T.F., Barnes, H.M., 2008. Reducing leaching of boron-based
Appendix A. Supplementary data
wood preservatives e a review of research. Bioresour. Technol. 99, 7312e7322.
Page, D., Hedley, M., Patterson, B., van der Waals, J., 2003. The Effect of Wood
Moisture Content and Timber Treatment on Initiation and Development of
Supplementary data related to this article can be found at http://
Decay in Radiata Pine Framing. Conﬁdential client report. Forest Research,
dx.doi.org/10.1016/j.ibiod.2013.09.003.
Rotroua, New Zealand.
Price Waterhouse Coopers, 2009. Weathertightness Estimating es the Cost.
Department of Building and Housing, Wellington, New Zealand.
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Biodeterioration & Biodegradation (2013), http://dx.doi.org/10.1016/j.ibiod.2013.09.003

Document Outline

Effectiveness of on-site remediation treatments for framing timber