BS EN 12404-2020 pdf free download.Durability of wood and wood-based products – Assessment of the effectiveness of masonry fungicide to prevent growth into wood of Dry Rot Serpula lacrymans (Schumacher ex Fries) S.F. Gray – Laboratory method
Close the vessels with screw cap without a hole a quarter of a turn less than full closure and sterilise the closed vessels in the autoclave (5.3.8) at (121 ± 2) °C for 30 min. Let them cool standing upright.
5.2.3 Nutrient solution, a mass fraction for 5 % aqueous solution of malt extract.
5.2.4 Equipment for chemical gas or for steam sterilization or access to a radiation source (see Annex B).
5.2.5 Carbon dioxide, compressed gas in cylinders.
5.2.6 Sodium chloride, saturated solution in water.
5.2.7 Portland cement, conforming to EN 413-1.
5.2.8 Hydrated building lime, conforming to EN 459-1.
5.2.9 Bricklaying mortar sand, quartz sand with a particle size equal to or less than 1 mm, washed under running tap water until the water is no longer turbid.
5.3 Apparatus
5.3.1 Culture vessels
Straight sided flat bottom glass culture vessels with an aperture of 50 mm to 60 mm (see Figure 3),provided with both screw caps without a hole, used for culturing the test fungus (9.1), and screw caps with a central hole equal in size to the outer diameter of the tube (5.3.2) plus the thickness of the tubing (5.3.3) in diameter.
NOTE The alternative type C.2 of test vessels described in EN 113, have been found to be suitable.
5.3.2 Rigid tubes, which can be sterilized using an autoclave (for example glass, or polyvinylidene fluoride) with an inner diameter of 35 mm to 46 mm and a length of at least 150 mm.
5.3.3 Tubing, with a diameter corresponding to the outer diameter of the rigid tubes (5.3.2) with a wall thickness of (1,0 ± 0,5) mm and cut into lengths of (40,0 ± 1,0) mm capable of being sterilized using an autoclave.
NOTE Tubing made of rubber has been found to be suitable.
5.3.4 Inert supports of maximum thickness 3 mm and when in use, do not obscure more than 10 % of the mortar surface.
NOTE Stainless steel washers of overall diameter 25 mm have been found to be suitable. Two supports are required for each test assembly.
5.3.5 Conditioning chamber, well ventilated and controlled at (20 ± 2) °C and (65 ± 5) % relative humidity.
5.3.6 Culture chamber, dark and controlled at (22 ± 1) °C and (70 ± 5) % relative humidity.
5.3.7 Drying oven, capable of being controlled at (45 ± 1) °C.
5.3.8 Autoclave, adjustable to (121 ± 2) °C.
5.3.9 Containers, to prepare the mortar and the preservative solutions, made of a material that does not react with their contents.
5.3.10 Mortar mould apparatus, consisting of a plastic frame for example polyvinyl chloride (PVC) with a height of (10 ± 0,5) mm, a porous support (for example clay house building bricks, ceramic plates) to absorb the excess water in the fresh mortar and a cloth (for example muslin cloth, cheese cloth) with the same dimensions as the frame to aid demoulding the mortar specimens (see Figure 2).
5.3.11 Plastic lath, used to smooth the surface of the mortar after casting in the plastic frame.
5.3.12 Circular tamper with a flat base, a diameter of 3 mm to 5 mm to less than the internal diameter of the rigid tube (5.3.2), and at least 50 mm longer than the rigid tube.
5.3.13 Racks on which to place the treated mortar test specimens an example is shown in Figure 1.
5.3.14 Sterile single-use pipettes of (1,0 ± 0,1) ml content.
5.3.15 Ordinary laboratory equipment, including for example balances accurate to 0,01 g, sealable
containers, forceps.
5.3.16 Microbiological safety cabinet, providing protection to the operator and to the work.
6 Sample of the preservative
The sample shall be representative of the product to be tested. It shall be identified as specified
in EN 599-1.
7 Mortar test specimen
7.1 Preparation of mortar
Dry a quantity of the quartz sand (5.2.9) in the drying oven (5.3.7) at (45 ± 1) °C. Measure out nine parts by volume of the dried quartz sand and weigh, then place into a container (5.3.9). Add two parts by volume hydrated building lime (5.2.8) and one part by volume Portland cement (5.2.7) and mix thoroughly. Add 16 ml water (5.2.1) per 100 g quartz sand and mix until a homogeneous mortar is obtained.
7.2 Preparation of mortar specimen
Before casting the fresh mortar in the mortar mould apparatus (5.3.10), soak the porous support in water for 30 min. Place the cloth and plastic frame on the porous support. Cast the fresh mortar in the frame and smooth the surface with the plastic lath (5.3.11). Push the rigid tubes gently in the fresh mortar until the bottom of the tube touches the support. Smooth the surface of the mortar inside the tube using the circular tamper (5.3.12) (see Figure 2).
Remove the mortar from around the outside of the tubes and cover the tops of the tubes with a moistened cloth. Store the tubes vertically, with the mortar test specimens at the bottom, in the conditioning chamber (5.3.5) for five weeks.
NOTE The moistened cloth prevents the mortar from drying out too quickly but can be removed after the first week of conditioning.BS EN 12404 pdf download.