5.3. Microscopic fungus-provisionProficiency with the macroscopic provision no clear characteristics for a type and degree of the damage is determined, then, a microscopic provision offers itself. The sampling, whose - preparation, the implementation and evaluation of the microscopy of fungus - and wood-materials requires enough technical knowledge and practical experiences beside the corresponding laboratory-technical installation. Picture: Microscopic contemplation, plate-hyphas from the fruit-work period of a fruit-body with rest similar ends (characteristics form for it dry rot) [white, Wagenführ, Krus S. 55] Vessel-hyphas of approximately become in the cord-mycelium 5...60 μm in the diameter found. they are together-stored in large number and carry ring-thickenings. The fiber-hyphas become up to 5 μm thickly, is somewhat stiff and greenish refractive. The fiber-hyphas are completely fasten-free. If a doubt-free allocation possibly is not even at microscopic provision about a certain fungus-type, the extensive fight-measures are to be grasped like by attack against it dry rot. The DIN 68800 part 4 point 4.2.1. mean a return-cut "... with dry rot and used dry rot-types by at least 1 m in longitudinal direction...". With static problems, the safe distance can be shortened by 0,50 m, to this further explanation for these exception conditions in the Beuth-commentary S. 83ff. The financial recovery is 1,5 m (fill and stonework) in longitudinal direction and, to execute as far as to the next not attacked blanket-great commissure. Case in point: An affection is available at the great commissure-head. The blanket-great commissure inclusive Dielung, fill, faulty-base, to expose for the installing the tab, is. 30 cm are at clear provision of a wet-rottenness-fungi to be done over the visible affection. With the dry rot 100 cm. Also with the affection for a wet-rottenness-fungi, parts of the fill and adjacent woods are to be exchanged. The scope of the uncovering is determined by the length of the tabs. The additional redevelopment-expenditure, for example for wood-great commissure-covers, that is damaged by it dry rot, must be not essentially bigger with it. In the practice, tabs in the length of 3 to 4 m with dowel and screw thread-poles often are used. If you take place an optimal material-drawing selection and an improved static link between shortened blanket-great commissures and the tabs here, so a shorter tab-length can be chosen or respectively with same tab-length the safe distance to be shortened can be chosen bigger at the attacked blanket-great commissure. The microscopic provision of a wood-destructive fungus then attains threatened valuable art-objects and monument-protected construction-substance at meaning, if static problems are available, or attacks respectively and redevelopment-costs are saved by the Eingrenzung, and the construction-substance can be gotten. Heeding is that several tests of different places always are necessary for a damage-provision and ascertainment of the scope. The request of the sampling was referred to ready above. Important microscopic characteristics result from the examination of spores, Substrate-mycelium, fruit-bodies, cords and Surface-mycelium. The tests to this usually become angefärbt in order to accentuate certain typical structures. With older or soiled tests is to be expected the appearance of molds. With not adequately representative tests, this can lead to misinterpretations. The provision about the DNA (Desoxyribonukleinsäure) is new. | |
| Content A. Biology the holzzerst. Fungi and insects B. Serpula lacrimans (Real house-sponge) 1. Damage-picture 2. Growth factors 2.1. Humidity 2.2. Temperature 2.3. Influx light / air 2.4. Function of the mycelium 2.5. Characteristics mycelium 2.6. Cytologische processes 2.7. Spores 2.8. Environment-influxes 3. Health endangering 4. dry rot types 5. Regulation-methods 5.1. Broadly 5.2. Macroscopic 5.3. Microscopic 6. Reorganization measures 7. Damage-areas 8. remediation own-service - Bibliographical review - Statistics cases of damage - Duty of notification ![]() Roof-projectile-development, molds and moist brickwork |
© www.ib-rauch.de | Imprint
| eBooks | 10/2005 ![]()
building material Construction-physics Preservation of structures Expertise Wood Immovable Residential-climate
Consulting engineers, work-formation and construction-biology Peter Rauch - Leipzig -