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.
78 nodes · 130 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.
- StandardCEN/TS 15083-1 / -2 — Determining natural durability by laboratory testClause 6–9. Part 1 gives the basidiomycete test for durability classification; Part 2 gives the soft-rot test in unsterile soil. Both express durability as the x-value — mass loss of the test species divided by mass loss of the reference (Scots pine sapwood or beech) — which is the route into EN 350 durability classes for species and modified wood.
- Climate zoneCoastal ScotlandCfb — temperate oceanic · 2–18 °C
- SpeciesDouglas FirPseudotsuga menziesii · DC 3–4 (moderately to slightly durable)
- Climate zoneDubai, UAEBWh — hot desert, coastal · 18–48 °C
- StandardEN 113-1 / EN 113-2 — Laboratory determination of resistance to basidiomycetesClause 5–8. Measures mass loss of small clear specimens after 16 weeks of exposure to defined decay fungi (e.g. Coniophora puteana, Trametes versicolor) on malt agar. EN 113-1 covers preservative efficacy; EN 113-2 covers determining the durability of wood and wood-based materials. Mass loss is a laboratory ranking, not a service life.
- StandardEN 12512 — Cyclic testing of timber joints with mechanical fastenersClause 5–8. Defines the quasi-static cyclic loading protocol used to determine ductility, strength degradation between cycles and equivalent viscous damping of timber connections — the experimental basis for the behaviour factors used in seismic and racking design.
- StandardEN 13183-1 — Moisture content by the oven-dry methodClause 4–6. Defines the reference procedure for determining moisture content: drying a specimen at 103 ± 2 °C to constant mass and expressing water mass as a percentage of oven-dry mass. Parts 2 and 3 cover electrical resistance and capacitance meters, which must be species- and temperature-corrected. Any moisture figure quoted without stating the method is not comparable.
- StandardEN 13183-2 / -3 — Moisture content by electrical resistance and capacitanceClause 4–6. Part 2 covers the resistance method with species and temperature correction and defined electrode depth; Part 3 covers the capacitance method. Both are indirect estimates calibrated against the oven-dry reference of EN 13183-1, and both lose accuracy above fibre saturation (about 28–30%).
- 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 13501-2 — Fire resistance classification of load-bearing elementsClause 7–8. Classifies elements by R (load-bearing capacity), E (integrity) and I (insulation) for a stated period in minutes, from standard furnace tests. For timber this is separate from the reaction-to-fire class of EN 13501-1; charring-rate design to EN 1995-1-2 is the calculation route to an R class.
- StandardEN 13986 — Wood-based panels for constructionClause 5 / Annex B. Harmonised specification for plywood, OSB, particleboard and fibreboard in construction: declared bending properties, reaction to fire, formaldehyde class (E1/E2), biological durability class and service-class suitability. Panel technical class (e.g. OSB/3) — not the panel type — sets the humid-conditions suitability.
- StandardEN 14080 — Glued laminated timber — requirements and bond performanceClause 5 / Annex B. Harmonised product standard for glulam and glued solid timber: lamination grading, finger-joint strength, adhesive bond integrity by delamination and shear testing, and target moisture content of 8–15 % at gluing with a maximum 4 % difference between laminations. Service class 3 use requires adhesives qualified for that exposure.
- StandardEN 14081-1 — Strength grading and CE marking of structural timberClause 5–7. Sets the requirements for visual and machine strength grading, factory production control and CE marking of rectangular structural timber. A strength class claim is only valid when the grading rule, species and source are declared together — a class cannot be assigned to timber of unknown provenance.
- StandardEN 14374 — Laminated veneer lumber for structural useClause 5–7. Sets requirements for LVL: veneer quality, bond durability class, dimensional tolerances and declared characteristic values. Bond class determines permitted service class; LVL is not automatically suitable for exterior exposure without a declared durable bond and detailing that keeps the edges dry.
- 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 152 — Preventive efficacy against blue stain in serviceClause 5–9. Tests coated and preservative-treated pine sapwood specimens for blue-stain fungal colonisation after weathering, reporting the proportion of stained surface. Blue stain is a disfigurement of sapwood without significant strength loss, and is assessed separately from decay resistance.
- StandardEN 15228 — Structural timber preservative-treated against biological attackClause 4–6. Requires that structural timber which is both strength-graded and preservative-treated declares penetration class and retention according to EN 351-1 alongside its strength class, and that treatment must not be used to compensate for detailing that traps moisture.
- StandardEN 15497 — Finger-jointed structural softwood timberClause 5–6. Specifies joint geometry, adhesive requirements, production control and proof-loading for finger-jointed structural timber. A finger-jointed member must meet the same characteristic strength as the declared class, and the adhesive must be qualified for the intended service class.
- 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 15978 — Assessment of environmental performance of buildingsClause 7–9 / Annex A. Defines the building-level calculation: the modular structure A1–A5, B1–B7, C1–C4 and D, the reference study period, the functional equivalent, and the rule that results from different assessments are only comparable when boundary, period and equivalent match.
- StandardEN 16351 — Cross-laminated timber — product requirementsClause 5–6. Specifies layup, board grading, adhesive bonding and dimensional tolerances for CLT, including a moisture content of 12 % ± 2 % at manufacture and declared rolling-shear performance. Exposure of CLT during construction is the dominant cause of in-service moisture problems; the standard assumes protected service classes 1 and 2.
- 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 16485 — EPD rules for round and sawn timberClause 6–7. Product-category rules for wood: mandatory declaration of biogenic carbon in and out of the system, the requirement that carbon uptake is only credited with evidence of sustainable sourcing, and consistent treatment of co-products and end-of-life energy recovery.
- StandardEN 16516 — Emission of regulated dangerous substances to indoor airClause 5–9. The European reference method for VOC and formaldehyde emission testing of construction products, defining the reference room, loading factors and the 28-day sampling point. It is the basis for national indoor-air labelling schemes, so an emission claim must state the day of measurement.
- StandardEN 16755 — Durability of reaction-to-fire performance for treated timberClause 4–6. Defines durability classes INT1 (interior, dry), INT2 (interior, humid) and EXT (exterior) for fire-retardant treated wood, based on hygroscopic behaviour and accelerated weathering followed by re-testing of reaction to fire. An exterior cladding claim of B-s1,d0 is unsupported unless the treatment holds an EXT classification.
- StandardEN 1912 — Species, source and grade to strength class assignmentTables 1–3. Maps recognised national grading rules, species and geographical source to the EN 338 strength classes. The same species graded under a different national rule or grown in a different region can fall into a different class, so species alone never determines strength class.
- StandardEN 1990 (Eurocode 0) — Design working life and reliability basisClause 2.3 / Annex A1. Sets indicative design working lives: 10 years temporary, 10–25 years replaceable components, 15–30 years agricultural, 50 years buildings and other common structures, 100 years monumental and bridges. Cladding and other replaceable elements are explicitly not required to match the 50-year structural life, which is the correct frame for maintenance-cycle arguments.
- 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 252 — Field test method for wood in ground contactClause 4–9. Defines the stake test: 500 × 50 × 25 mm specimens installed half-buried at a field site, inspected at least annually and rated 0 (sound) to 4 (failure). Median time to failure of the replicate set is the reported service life indicator. Results are site-specific and are not transferable to another climate without stating the reference site.
- StandardEN 302 series — Adhesives for load-bearing timber structuresParts 1–4. Tests bond strength after defined water and heat pre-treatments, delamination resistance, shear strength under moisture, and the adhesive's ability to accommodate wood shrinkage. It underpins the adhesive qualification referenced by EN 14080 and EN 16351.
- 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 338 — Strength classes for structural timberTable 1. Defines C-classes for softwood (C14–C50) and D-classes for hardwood, each with characteristic bending strength, modulus of elasticity and density. The class number is the characteristic bending strength in N/mm². Assignment is by visual or machine grading to EN 14081 and by species/source combination in EN 1912.
- 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 460 — Natural durability required per use classTable 1. Cross-tabulates natural durability class against use class to indicate whether untreated heartwood is acceptable, acceptable with reservations, or requires preservative treatment. In UC3 above ground, DC1–DC2 is normally acceptable, DC3 acceptable with reservations, DC4–DC5 not without treatment; in UC4 ground contact only DC1–DC2 is normally acceptable.
- StandardEN 599-1 — Performance requirements for preventive wood preservativesClause 4–5. Requires preservatives to be tested for efficacy against defined biological agents for each intended use class, with ageing procedures (EN 84 leaching, EN 73 evaporative) applied before biological testing. A product claim is only valid for the use classes and agents actually tested; ground-contact (UC4) claims require separate field or soil-bed evidence.
- StandardEN 717-1 / EN ISO 12460-1 — Formaldehyde release from wood-based panelsClause 6–9. Chamber methods measuring steady-state formaldehyde concentration in air at defined temperature, humidity, loading factor and air-exchange rate. Class E1 corresponds to a chamber value not exceeding 0.1 ppm; results are only comparable when chamber conditions and loading factor are stated.
- StandardEN 84 — Accelerated ageing by water leaching before biological testingClause 5–7. Specimens are vacuum-impregnated with water and then held through nine water changes over 14 days before decay testing. It is the mandatory pre-conditioning when a treatment's performance is claimed for use classes exposed to wetting, because it removes readily leachable active substances.
- 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 927-6 — Artificial weathering of coatings by UV and water exposureClause 5–8. Prescribes accelerated ageing in cycles of UV-A fluorescent irradiation, water spray and condensation for a defined number of hours, with assessment of adhesion, cracking and colour change. Artificial results rank systems but do not translate directly into calendar maintenance intervals — EN 927-3 natural exposure is required for that claim.
- StandardEN ISO 10456 — Design thermal values and moisture conversionTable 3 / Clause 6. Gives tabulated design thermal conductivity and moisture conversion coefficients for building materials including softwood and hardwood, with the procedure for converting declared values to design values at in-service moisture and temperature.
- StandardEN ISO 12572 — Water vapour transmission of building materialsClause 6–10. Cup-method determination of water vapour resistance factor µ and sd-value under defined humidity gradients. Wet-cup and dry-cup results differ for hygroscopic materials such as wood, so the test condition must be stated whenever a µ value is used in a moisture-safety assessment to EN 15026.
- 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.
- StandardEN ISO 4628 series — Rating degradation of coatingsParts 1–5. Standard 0–5 rating scales for blistering, rusting, cracking and flaking by quantity and size, with reference pictures. It provides the vocabulary used in EN 927-3 and EN 927-6 assessments so coating condition can be compared between exposure sites and dates.
- 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.
- 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)
- StandardISO 13061 series — Physical and mechanical properties of small clear specimensParts 1–2, 13–14. Standardises determination of moisture content, density, radial and tangential shrinkage and swelling on small clear wood specimens. It supplies the reference dimensional-movement data used for detailing joints and cladding gaps; movement values must be reported with the moisture range they span.
- StandardISO 15686-2 — Service-life prediction proceduresClause 5–8. Sets out the systematic procedure for service-life prediction: define performance requirements, identify degradation agents, run accelerated and in-use exposure, then correlate. Prediction is only valid within the exposure range actually tested, and the dose–response relationship must be reported.
- StandardISO 15686-8 — Service-life prediction procedures (factor method basis)Clause 5–7. Sets out how a reference service life is converted to an estimated service life through agent-based factors covering material quality, design level, work execution, indoor and outdoor environment, in-use conditions and maintenance level. Requires the reference service life, each factor and its evidence base to be reported alongside the result, so any estimate is reproducible and auditable.
- StandardISO 21887 — International use-class framework for biological attackClause 4–5. The ISO counterpart to EN 335, extending the use-class logic to termite and marine-borer hazards that dominate outside northern Europe. Necessary when transferring a European durability specification to subtropical or tropical markets, where the governing agent may be insects rather than decay fungi.
- StandardISO 21930 — Core rules for EPDs of construction productsClause 7. The international core PCR: declared unit, cut-off rules, data quality requirements and the separate reporting of biogenic carbon storage from fossil emissions. Used where an EN 15804 declaration is not available, but the two are not interchangeable without checking the boundary.
- 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.
- 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)
- Degradation agentUV degradationLignin photodegradation causing surface greying, checking and pigment failure.
- SpeciesWestern Red CedarThuja plicata · DC 2 (durable)