WI-GRAPH v1.0.0 · open method
The Wood Knowledge Graph.
How species, climate zones, degradation agents, treatments, standards and built projects connect — derived from the same open data as the rest of WoodIntel, with no invented citations.
What this is
Every node here already exists somewhere on WoodIntel. This page just draws the connections explicitly: which species resist which decay mechanisms, which climates elevate which risks, which treatments mitigate them, and which standard each rule comes from. Click any node to see its full neighbourhood.
How edges are derivedNo invented research citations
Each edge in this graph carries a basis (a short factual derivation rule) and a source (a standard id, dataset id, or WI method equation already cited elsewhere on the site — never a new research citation). Species-to-agent edges come from the WI-SL resistance profile; climate-to-agent edges come from the climate driver values in the climate dataset; treatment edges come from the standards corpus; species-to-standard edges come from the Global WoodIntel Score's own source list.
48 nodes · 139 edges · Machine-readable: GET /api/public/v1/graph · CC BY 4.0
Type
- SpeciesAcetylated Radiata PinePinus radiata (acetylated) · DC 1 (very durable)
- TreatmentAcetylationNon-biocidal chemical modification of the cell wall, assessed by measured mass-loss and moisture-exclusion performance.
- ProjectAlpine Pedestrian BridgeGrindelwald, Switzerland · 2014
- Climate zoneCoastal ScotlandCfb — temperate oceanic · 2–18 °C
- ProjectDesert PavilionDubai, United Arab Emirates · 2022
- SpeciesDouglas FirPseudotsuga menziesii · DC 3–4 (moderately to slightly durable)
- Climate zoneDubai, UAEBWh — hot desert, coastal · 18–48 °C
- StandardEN 13501-1 — Reaction-to-fire classification (Euroclass)Clause 11. Classes A1, A2, B, C, D, E, F with smoke (s1–s3) and flaming-droplet (d0–d2) sub-classes. Untreated solid softwood ≥ 9 mm and ≥ 390 kg/m³ classifies as D-s2,d0 (CWFT, EN 14915/EN 14081). Class B-s1,d0 for timber cladding requires a certified fire-retardant treatment with EN 16755 durability class (INT1, INT2, EXT for exterior use).
- StandardEN 14915 — Solid wood panelling and cladding — harmonised product standardClause 4–5. Covers CE marking of solid wood cladding: reaction to fire, moisture content at delivery (typically 16 % ± 2 % for exterior cladding), thermal conductivity, and durability declaration referencing EN 350. Delivery moisture content outside the declared band is the most common cause of early cupping and open joints.
- StandardEN 15026 — Hygrothermal simulation of building componentsClause 5–6. Defines the boundary conditions and validation cases for transient heat and moisture transport modelling. Used to demonstrate that a ventilated timber rain-screen dries out: the accepted criterion is that wood moisture content stays below 20 % mass for the annual mean and does not exceed 25 % for extended periods.
- StandardEN 15804+A2 — EPD modules and declared impactsClause 6.3. Requires modules A1–A3 (product), A4–A5 (construction), B1–B7 (use), C1–C4 (end of life) and module D (benefits beyond the system boundary). Comparing timber products is only valid when the declared unit, service life and module set are identical; a cradle-to-gate A1–A3 number alone cannot be compared with a cradle-to-grave figure.
- StandardEN 16449 — Calculation of biogenic carbon stored in woodClause 4. Biogenic CO2 stored = mass of dry wood × carbon fraction (default 0.5) × 44/12. For a dry density of 450 kg/m³ this gives roughly 0.82 t CO2 per m³ of timber. The figure is a stored quantity, not an emission credit; EN 15804 module boundaries must state whether it is reported in A1–A3 and reversed in C3/C4.
- StandardEN 1995-1-1 (Eurocode 5) — Service classes and modification factor kmodClause 2.3.1.3 / Table 3.1. Service class 1: 20 °C, RH exceeding 65 % only a few weeks per year (EMC ~12 %). Service class 2: EMC ~20 % (covered external). Service class 3: higher moisture content, fully exposed. Design strength is reduced by kmod, which depends jointly on service class and load duration; moving from SC1 to SC3 typically cuts permanent-load kmod from 0.60 to 0.50.
- StandardEN 1995-1-2 (Eurocode 5, fire) — Charring rates for fire designClause 3.4.2 / Table 3.1. One-dimensional design charring rate β0 = 0.65 mm/min for softwood glulam with characteristic density ≥ 290 kg/m³, 0.50 mm/min for hardwood ≥ 450 kg/m³, and notional rate βn = 0.70 mm/min for softwood glulam. Residual cross-section is calculated by subtracting the char layer plus a 7 mm zero-strength layer.
- StandardEN 335 — Use classes for biological exposureClause 5. Defines UC1 interior dry; UC2 interior with occasional condensation; UC3.1 exterior above ground, coated and shedding water; UC3.2 exterior above ground, frequently wetted; UC4 in contact with ground or fresh water; UC5 in salt water. Vertical rain-screen cladding with ventilated cavity is normally UC3.1; horizontal decking, sills and cappings are UC3.2. Every horizontal or water-trapping detail effectively raises the use class by one step.
- StandardEN 350 — Durability classes of heartwood against wood-destroying fungiAnnex B / Table B.1. Grades heartwood natural durability against basidiomycetes on a five-step scale: DC1 very durable, DC2 durable, DC3 moderately durable, DC4 slightly durable, DC5 not durable. Indicative field ratings: European oak DC2, western red cedar DC2–3, Siberian larch DC3, Douglas fir DC3–4, Norway spruce DC4, sapwood of all species DC5. Durability is a heartwood property only; sapwood proportion must be declared separately.
- StandardEN 350 — Performance-based durability and modified woodClause 4 / Annex C. Allows durability of modified or treated wood to be expressed as a performance class derived from test data (EN 113, CEN/TS 15083) rather than species tables. Acetylated and thermally modified timber are assessed on measured mass-loss and moisture-exclusion performance, not on the untreated species class.
- StandardEN 351-1 — Penetration and retention classes for preservative-treated timberClause 5 / Annex A. Defines penetration classes NP1–NP6 and requires declared retention for the intended use class. UC3 above-ground cladding typically requires NP2–NP3; UC4 ground contact requires NP5–NP6 with full sapwood penetration. Treatment declared without a penetration class and retention value is not verifiable.
- StandardEN 927-1 — Classification of exterior wood coating systemsClause 4. Classifies coatings by end-use (stable, semi-stable, non-stable joinery) and by film thickness/permeability: minimal (<5 µm dry), thin (5–20 µm), medium (20–60 µm), thick (>60 µm). Penetrating and semi-transparent systems fall in the minimal/thin bands, which erode rather than flake and therefore favour recoating without stripping.
- StandardEN 927-3 — Natural weathering test for coating systemsClause 6–8. Specifies 45° south-facing exposure of coated panels for a minimum of 12 months, with assessment of cracking, flaking, chalking, blistering and blue-stain. Results are the basis for maintenance-interval claims; a claim without EN 927-3 or EN 927-6 (artificial weathering) data should be treated as unverified.
- StandardEN ISO 15927-3 — Driving-rain index from climate dataClause 4. Derives the wall-driving-rain index from hourly wind speed, direction and rainfall. Airfield index (litres/m² per year) above 500 indicates severe exposure requiring a drained and ventilated cavity; below 200 is sheltered. This is the correct basis for grading façade moisture load — not annual rainfall alone.
- SpeciesEuropean OakQuercus robur · DC 2 (durable)
- TreatmentFire-retardant treatmentCertified treatment required to reach Euroclass B-s1,d0, with EN 16755 durability class for exterior use.
- ProjectFjord Primary SchoolStavanger, Norway · 2016
- Degradation agentFreeze-thaw cyclingRepeated ice formation in end-grain and checks, opening surface cracks over successive winters.
- Degradation agentFungal rotBasidiomycete decay of the cell wall, graded by EN 350 durability class.
- SpeciesIroko (FSC certified)Milicia excelsa · DC 1–2 (very durable)
- Degradation agentMarine borers & salt attackChloride-driven fastener corrosion and, in UC5 exposure, marine organism attack.
- Degradation agentMould & blue-stainSurface fungal growth favoured by sustained high moisture content, assessed under EN 927-3 weathering.
- ProjectNorth Sea HouseThy, Denmark · 2019
- SpeciesNorway SprucePicea abies · DC 4 (slightly durable)
- Climate zonePacific North-West, USACsb — warm-summer mediterranean · 3–24 °C
- TreatmentPenetrating / semi-transparent coatingMinimal-to-thin film coatings (EN 927-1) that erode rather than flake, favouring recoat-without-strip maintenance.
- TreatmentPreservative impregnationPressure impregnation to a declared penetration class (NP) and retention for the intended use class (EN 351-1).
- Climate zoneRiyadh, Saudi ArabiaBWh — hot desert · 12–46 °C
- SpeciesRobinia (Black Locust)Robinia pseudoacacia · DC 1–2 (very durable)
- SpeciesScots Pine (heartwood)Pinus sylvestris · DC 3–4 heartwood; sapwood DC 5 but treatable
- SpeciesSiberian LarchLarix sibirica · DC 3 (moderately durable)
- Climate zoneSingaporeAf — tropical rainforest · 25–33 °C
- Climate zoneStockholm, SwedenDfb — humid continental · -6–22 °C
- SpeciesSweet ChestnutCastanea sativa · DC 2 (durable)
- TreatmentThermal modificationHeat treatment that removes decay-feeding sugars, assessed as a performance class under EN 350 clause 4.
- SpeciesThermally Modified AshFraxinus excelsior (TMT) · DC 1–2 after modification
- SpeciesThermally Modified PinePinus sylvestris (TMT) · DC 2–3 after modification (process dependent)
- ProjectTimber Assembly HallLondon, United Kingdom · 2021
- ProjectTimber High-RiseStockholm, Sweden · 2020
- Degradation agentUV degradationLignin photodegradation causing surface greying, checking and pigment failure.
- SpeciesWestern Red CedarThuja plicata · DC 2 (durable)