Lisø PhD Dissertation Manuscript - NTNU

More documents

Recommendations

Info

Concluding remarks and further work Untreated wood cladding that is properly ventilated and drained has a relatively long lifetime even in harsh climates. A high-performance cladding is to a large degree ensured if the principle of two-stage tightening is applied. Still, the lifetime of the cladding is strongly dependent on the climatic impact on site. Preservative measures, both surface treatment and impregnation, is used to enhance the lifetime of the material. The presented national map of climate index distributions allows for geographically differentiated guidelines on protective measures in the form of impregnation, surface treatment or precautions in design of wooden structures. The map will be used as an important instrument in the continuous development of Norwegian technical guidelines for wooden building enclosures (e.g. the SINTEF Building Research Design Sheets, see Lisø et al., 2005), allowing for climate differentiation in both protective design and preservative treatment of wood. Extended use of climate-differentiated preservation can contribute to a reduction of the economic and environmental costs associated with preservative measures. The opportunities for both prolonged maintenance intervals and extended use of environmentally friendly wood preservatives in different climates should be subject to further investigations. The quantitative connection between wood decay rates and climatic impact should also be further investigated. The moisture transfer mechanisms of wood are highly influenced by the surrounding climatic conditions. Field- and laboratory investigations are needed to further improve the reliability of the index for Norwegian climatic conditions, including measurements of decay rates in different climates and in different types of wood. Important issues to be considered are the low temperature limit for growth in wood decaying fungi in evidence in Norway, and appurtenant observed growth rates to temperature. The built environment is experiencing extensive degradation and damage every year due to climatic impact. Projected changes in climatic conditions will further enhance vulnerability within the construction industry and the built environment (Lisø et al., 2003b; Lisø, 2005). Climate change can increase the risk of decay of wood structures. Climate indices allowing for quantitative assessment of building enclosure performance or decay potential may be an important element in the development of adaptation measures to meet the future risks of climate change in different parts of the world. This and other indices, with established quantified relations between climatic impact and material behaviour or building performance, can be used as a tool for evaluation of changes in functional requirements or decay rates due to climate change under global warming incorporating data from regional- and local-level climate change scenarios as indicated in this paper. The presented work represents a first step towards establishing such measures. Thorough analyses of projected future climate index values, including assessment of uncertainty ranges, will be published in due course. Page 6 of 7
Acknowledgements This paper has been written within the ongoing SINTEF Building and Infrastructure Research & Development Programme “Climate 2000 – Building constructions in a more severe climate” (2000 – 2007), strategic institute project “Impact of climate change on the built environment”. The authors gratefully acknowledge all construction industry partners and the Research Council of Norway. References Benestad, R.E. (2005) Climate change scenarios for northern Europe from multimodel IPCC AR4 climate simulations. Geophysical Research Letters 32, L17704. Birkeland, Ø. (1963) Rain Penetration Investigations – A summary of the findings of CIB Working Commission on Rain Penetration. Norwegian Building Research, Oslo Institute. Isaksen, T. (1966) Rain penetration in joints. Reprint 119. Norwegian Building Research Institute, Oslo. Lisø, K.R. (2005) Integrated approach to risk management of future climate change impacts. Building Research & Information (in press). Lisø, K.R., Kvande, T. and Thue, J.V. (2005) High-performance weather-protective flashings. Building Research & Information 33(1), 41-54. Lisø, K.R., Time, B., Kvande, T. and Førland, E.J. (2003a) Building enclosure performance in a more severe climate. In Carmeliet, J., Hens, H. and Vermeir, G. (Eds): Research in Building Physics – Proc. of the 2nd International Conference on Building Physics, A. A. Balkema Publishers, Lisse, pp. 309- 317. Lisø, K.R., Aandahl, G., Eriksen, S. and Alfsen, K.H. (2003b) Preparing for climate change impacts in Norway’s built environment. Building Research & Information 31(3-4), 200-209. McCarthy, J.J. et al. (2001) Climate Change 2001: Impacts, Adaptation and Vulnerability, Cambridge University Press, Cambridge. Nore, K., Lisø, K.R. and Thue, J.V. (2005) Statistical analysis of wooden cladding moisture response to climate parameters. 3rd International Building Physics/Science Conference, Montreal, Canada, August 27-31, 2006 (accepted). Norwegian Building Research Institute and Mycoteam as (1997) Building Research Design Sheet 720.082 Mugg-, råte- og fargeskadesopp. Angrepsformer og bekjempelse. Building Research Series, Norwegian Building Research Insitute, Oslo [in Norwegian]. Scheffer, T.C. (1971) A Climate Index for Estimating Potential for Decay in Wood Structures above Ground. Forest Product Journal 21(10), 25-31. Scheffer, T.C., Verrall, A.F. and Harvey, G. (1963) On-site preservative treatments: Their effectiveness for exterior millwork of different species and in various climates. Forest Product Journal 13(1), 7-13. Sedlbauer, K. (2001) Vorhersage von Schimmelpilzbildung auf und in Bauteilen. PhD Dissertation, Lehrstuhl für Bauphysik, Universität Stuttgart, Stuttgart [in German]. Setliff, E.C. (1986) Wood Decay Hazard in Canada based on Scheffer’s climate index formula. The Forestry Chronicle, October 1986, 456-459. Page 7 of 7
Page 1 and 2:
Building envelope performance asses
Page 3 and 4:
Lisø, K.R./ Building envelope perf
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
BUILDING RESEARCH &INFORMATION (200
Page 43 and 44:
LisÖ et al. on how to cope with an
Page 45 and 46:
LisÖ et al. the exposure to contin
Page 47 and 48:
LisÖ et al. business premises. The
Page 49 and 50:
LisÖ et al. construction industry
Page 51 and 52:
Research in Building Physics, Carme
Page 53 and 54:
4 CLIMATE CHANGE SCENARIOS FOR NORW
Page 55 and 56:
with large amounts of precipitation
Page 57 and 58:
will most likely be worse, even wit
Page 59:
Graves, H.M. & Phillipson, M.C. 200
Page 62 and 63:
766 Nordvik and Lisø The topic of
Page 64 and 65:
768 Nordvik and Lisø into the futu
Page 66 and 67:
770 Nordvik and Lisø climate chang
Page 68 and 69:
772 Nordvik and Lisø 0 Â Â = p d
Page 70 and 71:
774 Nordvik and Lisø probably to a
Page 73 and 74:
BUILDING RESEARCH &INFORMATION (200
Page 75 and 76:
cost of repairing process-induced b
Page 77 and 78:
change in quality (Mehus et al., 20
Page 79 and 80:
on the impacts of different climati
Page 81 and 82:
different strategies: risk-based, p
Page 83 and 84:
Page 85 and 86:
Learning from experience - an analy
Page 87 and 88:
An important aspect of the programm
Page 89 and 90:
Concrete walls 32 % LECA masonry 10
Page 91 and 92:
construction industry, and academic
Page 93 and 94:
BUILDING RESEARCH &INFORMATION (JAN
Page 95 and 96:
greater variations (Lisø et al., 2
Page 97 and 98:
Typical problem areas and recommend
Page 99 and 100:
Figure 3b Recommended design of win
Page 101 and 102:
Figure 7 Example showing the recomm
Page 103 and 104: Figure 11a Poor solution for a £as
Page 105 and 106: Acknowledgements This paper was wri
Page 107 and 108: Climate adapted design of masonry s
Page 109 and 110: 2. Masonry defects in Norway 2.1. S
Page 111 and 112: Fig. 2. Example illustrations of th
Page 113 and 114: The presented results are in good a
Page 115 and 116: appropriate in a more severe type o
Page 117 and 118: screen in a two-stage weatherproofi
Page 119 and 120: INCREASED SNOW LOADS AND WIND ACTIO
Page 121 and 122: The hurricane (Beaufort number 12)
Page 123 and 124: The extensive revisions of the code
Page 125 and 126: The number of buildings investigate
Page 127 and 128: As is apparent from the values in t
Page 129 and 130: climate change is now dominated by
Page 131: TABLE 3. Summary of findings Struct
Page 134 and 135: Lisø, K.R./ Building envelope perf
Page 136 and 137: temperature of -4°C or less. See F
Page 138 and 139: Today, frost resistance of brick, c
Page 140 and 141: degree of saturation, freezing will
Page 142 and 143: accelerated frost damage or frost d
Page 144 and 145: A possible objection to the present
Page 146 and 147: [17] Dührkop H., Saretok V., Sneck
Page 149 and 150: Decay potential in wood structures
Page 151 and 152: Wood decaying fungi will only be ac
Page 153: to promote decay prevails. Two of t
Page 158 and 159: (a driving rain gauge), however, is
Page 160 and 161: Fig. 1. Map of Norwayshowing the lo
Page 162 and 163: Frequency 25 20 15 10 5 0 highest p
Page 164 and 165: interesting to compare those result
Page 167 and 168: Effects of wind exposure on roof sn
Page 169 and 170: In ISO 4355 ”Bases for design of
Page 171 and 172: variety of roofs and wind exposures
Page 173 and 174: Li and Pomeroy [13] evaluated hourl
Page 175 and 176: Fig. 5. Exposure coefficients for 3
Page 177 and 178: meteorological stations are expecte
Page 179 and 180: Many of the meteorological stations
Page 181 and 182: the ground with return period of 30
Page 183: References [1] Standards Norway. De
show all

Lisø PhD Dissertation Manuscript - NTNU

Create successful ePaper yourself

Delete template?

Save as template?