Program for calculating the strength of wooden rafter roofs

Calculation of the strength of the rafters, and the lathing from the sections of the timber and boards you specified. All parameters are easily set - loads, spans, sections, spacing, etc. The program is in Exel format, the necessary places (indicated by color, and in any other) insert your data. Get an immediate response. Gives a good opportunity to vary with parameters. There is an incompatibility with Microsoft Excel from Office 2003.
Here is a screen http://yx-kakoi.narod.ru/jpg/skrin-stropila.jpg
The calculation was made according to the manual: Shishkin "Examples of calculation of structures made of wood and plastic" Moscow, Stroyizdat 1974 and SNiP II-25-80