Embed Size (px)
Citation preview
Thatch Naturallya short introduction
Joost KreugerVakfederatie Rietdekkers
2
Vakfederatie Rietdekkers• branche organisation• knowledge and expertise• education• quality control• mediation
• www.riet.com
3
4
5
contents• short history• waterreed• thatching technique• durability• key features• examples• questions
6
Short HistoryThe natural roofing material
• in search of shelter• local materials• variety of materials
7
8
9
10
11
12
13
14
15
16
17
18
19
thatch survived• most durable• specialism• 100.000.000 € industry in Holland
20
21
22
WaterreedAnual so renewable
38
Thatching techniqueHard labour craft
• minor changes in craft over the years
• some different and more durable materials• construction changes• change in design
39
40
• Building details roof
41
• Building details wall
42
43
44
45
46
47
48
49
50
51
52
53
54
56
DurabilityEnter architect
57
Moisture determines life expectancy• slope• construction• detailed engineering• Surrounding of building• orientation• craftsmanship• quality of thatch• maintenance
58
Moisture determines life expectancy• slope > enter architect• construction > enter architect• detailed engineering > enter architect• surrounding of building• orientation• craftsmanship• quality of thatch• maintenance
59
Moisture determines life expectancy• slope > enter architect• construction > enter architect• detailed engineering > enter architect• surrounding of building• oriëntation• craftsmanship• quality of thatch• maintenance
62
slope• minimum 30° for short distances (gable etc)• minimum 45° for longer distances
Zo hoort het !
Grotere hellingshoek? de combinatie plat dak en riet
70
Nog beter !
75
Moisture determines life expectancy• slope > enter architect• construction > enter architect• detailed engineering > enter architect• surrounding of building• oriëntation• craftsmanship• quality of thatch• maintenance
• Traditional construction• No R value• Fire risk
Het moderne “schroefdak”
• Modern construction• R=1,5 min• No fire risk
81
constructioneither:• open > sheds, barns• closed > homes, public buildings
• different kinds of insulation possible
82
Moisture determines life expectancy• slope > enter architect• construction > enter architect• detailed engineering > enter architect• surrounding of building• oriëntation• craftsmanship• quality of thatch• maintenance
less details > less moisture > higher life expectancy
every detail means:
• turning of thatch (less slope)• increase in thickness (less slope)• less sun and wind (less drying capacity)• less drain of water
gedraaid
Rietpakket dikker + overmaat aan water
Recreatieproject 80 woningen, 160 killen
Dak: dikte = 24 cm helling riet = 30°Kil : dikte = 46 cm helling riet = 14°
Life expectancy of a thatched valley
• slope = 75% of optimal• thickness = 75%• oriëntation (north) = 75%• Water volume = 75%• drying capacity= 75%
life expectancy: 75% x 75% x 75% x 75% x 75% = 24%
Life expectancy of roof +/- 32 yearsValley > 0,24 x 32 = 8 jaar.
oplossing
Make it open…• slope = 75% > 100%• thickness = 75% > 100%• oriëntation (north) = 75% > 100%• Water volume = 75% > 100%• drying capacity = 75% > 100%
Life expectancy increases from 8 years to 32
Nog beter !
95
key featureswhy thatch survived
96
thatched roof• renewable and natural• warm and soft• easily adapts in every surrounding• distinguished• pliable• high degree of formability• firesafe even without fire-retardant• high R values possible
97
Examplesthatch is a modern building material
99
veiliger !
