All about Wood

Wood is an organic natural material, each piece has unique features including colour, texture, knots and cracks.  This is all part of the appeal!  However it also means that it will change as it ages and also it will react to atmospheric conditions, for example if there is a prolonged hot and dry spell in the summer or a very wet and cold winter.

In warm weather the wood will shrink, and in wet weather it will expand.  These changes means that over time, stresses are set up throughout the wood which will result in cracks and splits appearing.  These cracks can appear alarming as they can be both wide and deep.  You should be prepared to check your play equipment regularly to note any changes in the timber.

These cracks and splits will occur more often in round-wood, than square cut wood as round timber comes from smaller trees which contain more heartwood and square cut wood is taken from trees with less heartwood so is less prone - although it does still occur.

The tp Climbing Frames and Swing Sets which Just tp Toys supply, that use round-wood is the tp Sherwood sets.  tp themselves state that:

"the tp round-wood playsets (wooden climbing frame and wooden swing sets) are dimensioned and designed to ensure that this (cracking and splitting) has no effect on their structural integrity.  However as a result of this characteristic, you should be prepared to check your wooden climbing frame or wooden swing so as to identify any splintering or lifting of the surface layers of the wood"

The specification from tp Toys allows for individual splits up to 15mm wide and deep on the Swing Beam (horizontal bar) and as the legs have a slightly smaller diameter; up to 12mm wide and deep on these before the strength is impacted.

Regarding their products which use square cut timber, tp say: