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.
8.3 Provision of wood test specimens
Cut the wood test specimen from planed strips having a cross section of (25 ± 0,5) mm x (15 ± 0,5) mm,
in which the growth rings may run in any direction.
8.4 Dimensions of wood test specimens
The dimensions, measured at a mass fraction of (12 ± 1) % moisture content, shall be (20 ± 0,5) mm
(length) x (25 ± 0,5) mm x (15 ± 0,5) mm.
9 Procedure
9.1 Culturing the test fungus
Inoculate the culture medium in each culture vessel (5.3.1) not more than one week after sterilisation of the culture medium (5.2.2) and using stock cultures of the test fungus which are not more than four weeks old. Store the inoculated culture vessels in the culture chamber (5.3.6) until the test fungus has covered the surface of the culture medium; use within one week of this stage being reached. The test fungus shall not be visibly contaminated by other organisms.
9.2 Treatment of mortar test specimens
Use the test preservative (see Clause 6) as delivered by the supplier or diluted into a container (5.3.9) according to the sponsor’s instructions. The application rate(s) shall be as recommended by the supplier but shall not exceed 500 g/m2. Calculate the amount of preservative solution to be applied to each mortar test specimen. Using a pipette, spread the treatment solution evenly over the mortar surface within the tube; determine the exact amount applied by weighing before and after application. Return the treated mortar test specimens to the rack (5.3.13) and store in the conditioning chamber (5.3.5) for one week.
9.3 Preparation of wood test specimens
Not more than one week before the fungus testing (see 95), impregnate the wood test specimens with the nutrient solution (5.2.3), according to EN 113:1996, 8.2.2.
NOTE The impregnation of the wood test specimens with a nutrient solution encourages fungal infestation.
9.4 Sterilization procedures
Put a wad of non-absorbent cotton wool in the top of the tube of each treated mortar test specimen and each untreated mortar test specimen. Screw the lids of each specimen into empty culture vessels (5.3.1) and close the lids to one quarter of a turn less than full closure.
Sterilize all the assemblies using an appropriate procedure for each preservative under test (see Annex B).
In case of doubt on the heat sensitivity of the preservative, it is recommended to contact the supplier.
Sterilize the water, the supports (5.3.4), the nutrient treated wood test specimens (see 93) and the forceps in the autoclave (5.3.8) for 30 mm at (121 ± 2) °C.
11 Test report
The test report shall include at least the following information (see also Annex C for an example):
a) the number and date of this document (EN 12404:2020);
b) the name of the supplier of the preservative under test;
c) the type of the preservative tested together with its unique name or code and with an indication of whether or not the composition has been declared;
d) the name and concentration of active ingredient;
e) the solvent or diluent used;
f) the species and strain number of the fungus used;
g) the concentrations of the preservative tested expressed as percentages by mass;
h) the applications rate in g/m2 of the preservative under test;
i) the means of sterilization used for the mortar test specimens;
j) the date of the exposure of the mortar test specimens to fungus.