The female lays eggs into the cracks of wood to a depth of about 20-30 mm. After 1-3 weeks hatch
the larvae, starting eat timber (see Fig 2) [2] and [3].
Figure 2. Old-house borer – larva
These larvae eat the wood inside the cross-section so the surface damage is not visible at first
sight. Most of these buildings are currently historically protected and any destructive intervention
into the structure when assessing its condition is prohibited.
To assess condition of the elements and the whole structure is possible only by using
non-destructive methods – especially visual assessment, which is not fully conclusive, because of
evaluation only superficial aspects.
The quality of wood inside the element for design of proper rehabilitation actions can be obtained
through complementary semi destructive methods. One of them is resistograph testing.
The object of the exploration is the description of elements material quality of roof trusses over
the object of castle (see Fig. 3) with a proposal for further progress of potential rehabilitations on
the base of the gathered data.
Figure 3. Castle – roof truss
