BS 12404:2020 pdf 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

BS 12404:2020 pdf 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 The carbon dioxide reduces the alkalinity of the mortar. The alkalinity of the mortar test specimenscan be checked with a phenolphthalein colouring method.Prepare a mass fraction of 1 % solution ofphenolphthalein in ethanol.Remove two dried mortar test specimens from the tubes and split themin half.Spray the phenolphthalein solution on the cut surfaces.If a red colour develops the mortar testspecimens need further curing. When the colour of the cross sections remains unchanged the mortartest specimens are ready for further preparation. 7.4 Leaching of mortar test specimen Immerse the cured mortar test specimens(7.3) in deionized water for two weeks. Use 300 ml water permortar test specimen and change the water twice per working day. After this leaching period,fill each tube with a 100 mm high water column and record the time taken forthe water to pass through the mortar test specimen. Reject specimens with a time of greater than 90 s.Store the acceptable mortar test specimens for at least two weeks in the conditioning chamber(5.3.5)before continuing with the testing. 7.5 Number and distribution of mortar test specimensDistribute the mortar test specimens (7.4) as follows: -treated mortar test specimens: use at least 10 mortar test specimens for each combination of concentration and application rate.untreated control mortar test specimens: use at least 10 control mortar test specimens. For the testing, on each of the acceptable mortar test specimens slide a length of tubing (5.3.3) over theend of the rigid tube remote from the mortar so that one end of the tubing coincides with the end of therigid tube remote from the mortar.Insert the tubing covered tube through the hole in a screw cap froma culture vessel (5.3.1). Place the mortar test specimens in the rack (5.3.13) (see Figure 1). 8 Wood test specimens 8.1 Species of wood The following wood species shall be used for the test.Scots pine (Pinus sylvestris Linnaeus). 8.2Quality of wood The Scots pine shall be exclusively sapwood containing little resin. The wood shall be free from knots, cracks, stain, decay, insect damage or other defects. The wood shall not have been water- stored, floated, chemically treated or steamed. Wood that has been kiln dried at temperatures below 60 C can be used. 8.3Provision...