Much of a builder's work is centred around handling wood, and if you're building from scratch, then knowing what to look out for when buying lengths of wood from a timber merchant is important. At AbleSkills, many different types of course are on offer which have been put togther to cater for all types of requirements, from training over the weekends, 10 day carpentry courses or City & Guilds NVQs over an 8 week period, to the ever popular Kitchen Fitting course! And there are many other types of learning diploma courses which will help you get started.Timber is the most sustainable building product available and is a naturally renewable resource. Over 97% of softwood timber purchased in the United Kingdom is sourced from Europe. Certification labels like PEFC - Programme for the Endorsement of Forest or FSC (Forest Stewardship Council) guarantee the renewable nature ofsoftwoods and hardwoodsThere are many different purposes that timber can be used for and each purpose may call for specific characteristics. It is essential to know how strong timber is. Timber strength grading is needed to ensure timber has enough strength for a particular job, e.g. a floor joist or a roof truss. Knowing the strength of timber reduces costs by helping to avoid over-specification. Grading can be undertaken visually or by machine. Visual strength grading uses the grader's experience across many diverse factors to estimate the load that a length of timber will be able to carry in service. Machine strength grading is best suited to high volumes of timber where the variety and cross section are not changed very often. When a piece of timber is sawn into smaller pieces, it has to be re-graded.Machine grading is based on the link between strength and stiffness. The machine grades individual piece and stamps it with the relevant mark. The rules governing strength grading and structural uses of timber are detailed in British and European standards. A section of low grade timber cut from a strong species may be equivalent in strength to a high grade timber from a weaker tree variety. To make specifying easier, species and grades are grouped into strength categories of similar strength. Strength classes range from C14 to C50 for softwood and D30 to D70 for hardwoods. The higher the number, the stronger the timber. The most common grade for softwood carcassing is C16.When calculating the size of a timber member is required for a particular span, the required strenth class can be identified by consulting span tables. These tables also specify what the greatest gap should be between each section or timber member.