EN 131-2-1993 pdf download.Ladders-Requirements , testing , marking.
temperature resistance have to he taken into account.
Glass-fibre reinforced plastics shall be protected against penetration of water and dirt. The surface shall be smooth. The fibres shall be embedded. The Barcol hardness according to EN 59 shall be at least 35.
3.1.4 Wood
3.1.4.1 Species of wood
For stiles, stanchions and cross struts species of timber shall be used which have a bulk density of at least 410kg/rn3. Suitable species of timber are for example fir (abies alba), larch (larix decidua), spruce (picea abies), pine (pin us sylvestris), Oregon pine (pseudotsuga nzenziesii, hemlock (tsuga heterophylla).
For rungs and steps species of timber shall be used which have a bulk density of at least 410 kg/mi in the case of softwood and of at least 620 kg/rn3 in the case of hardwood. Suitable species of timber are for example spruce picea abies), pine pinus syluestris), and cornelian cherry (corn us mas), beech fagus sylvatica), ash (fraxisnus excelsior), oak (q uercus robu r), robi na (robin ia pseudacacis). respectively.
The above mentioned bulk densities apply to a moisture content of 15 0/f)
Other species of timber having at least the same quality are admissible, too.
Parana pine (araucaria angustifolia 0. Kize.), Hem fir (abies magnifica), and Corsican pine pinus nigra Arnold) are excluded from the production of ladders.
3.1.4.2 General condition
Compression wood (in the case of softwood). defects caused by insects (as far as the mechanical strength is impaired), mistletoe fouling, reaction wood (in the case of hardwood), ring shakes, red rot (brown rot), white rot, and unsound knots are inadmissible.
3.1.4.3 Colour
Differences in colour, dependent on nature, which do not impair the strength of the wood
(for example redheart of beech, brownheart of ash), holding red streaks of spruce and fir up to 25 % of the surface, blue stain of pine are admissible.
3.1.4.4 Knots
3.1.4.4.1 Knots in stiles and supporting elements
On the entire length of the ladder traversing splay knots are inadmissible (see Figure 1).
Continuous pitch pockets are inadmissible. 3.1.4.6 Shakes
Continuous shakes3 are inadmissible. Shallow shakes1 are admissible up to a length of 100 mm.
3.1.4.7 Slope of grain (measured by the cut annual rings)
A deviation of the slope of grain from the longitudinal edges of the wood of 100 mm per 1 000 mm maximum is admissible (see Figure 4). Local deviations, e.g. at knot positions, are neglected.
3.1.4.8 Spiral grain.
A deviation of the grain direction from the longitudinal edges of the wood of not more than 50 mm per 1 000 mm. measured either with the help of shrinkage shakes or the scratching method is admissible (see Figure 5). The measurement is to be carried out in two faces perpendicular to each other. The largest deviation is decisive. In the case of rungs and steps, the grain ends, with the exception of knots, shall be at the rung or step ends.
3.1.4.9 Moisture conient (related to the kiln-dry weight) at time of manufacture
The moisture content of the wood is to be chosen according to the compensation moisture resulting from open air drying, e.g. max. 22 % in Great Britain, max. 18 % in Belgium and the Netherlands, max. l % in France and Germany, max. 20 % in Italy.
The moisture content of the rungs and steps respectively should, at the time of manufacture, be lower than that of the stiles.
3.1.4.10 Average width of annual rings
Admissible up to 4 mm maximum.
3.1.4.11 Laminated wood
The use of laminated wood is allowed for stiles if it is fabricated in accordance with recognized technical rules. The single pieces to be bonded shall be at least 2 000 mm. except for single parts at the upper and lower stile end. The distance between joints shall be at least 500 mm. The outer layers shall be continuous (not, fabricated in parts).
Another way of fabrication is allowed if it is assured that the bond has at least the same strength as grown wood.
3.1.4.12 Adhesives
For wooden ladders, only glues are permissible
which correspond to the requirements according to
EN 204 as follows:
Connections stile — rung: class D3
Laminated wood: class D4.EN 131-2-1993 pdf download.