Trees - how to safeguard them during construction work
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The information on this page is taken from the relevant British Standard (BS 5837:2005), 'Trees in relation to construction'. Further details are contained in the British Standard itself. To find out more or to obtain a copy visit the BSI website.
The advice applies equally to developers of large sites and to residents extending their houses.
The advice applies equally to developers of large sites and to residents extending their houses.
It is important to remember that all protective measures should be in place before any development work starts. It is advisable to complete all protective works before bringing any machinery or vehicles onto the site or carrying out any demolition or soil stripping.
The need for protection
A tree may take a century to reach maturity, but it can be damaged in only a few minutes.
Such damage is often caused because of failure to appreciate the vulnerability of trees - particularly the root system.
Such damage is often caused because of failure to appreciate the vulnerability of trees - particularly the root system.
Damage is frequently done to existing trees in the first few days of a contractor's occupation of a site.
The part of a tree most likely to be damaged is the root system. Because the roots aren't immediately visible, they're often ignored.
Damage to the trunk and branches of a tree rarely kills it, but may cause severe disfigurement.
The part of a tree most likely to be damaged is the root system. Because the roots aren't immediately visible, they're often ignored.
Damage to the trunk and branches of a tree rarely kills it, but may cause severe disfigurement.
Area to be enclosed by fencing
BS 5837 provides detailed guidance on the minimum area around the tree which should be left undisturbed.
As a simple alternative, BS 5837 also suggests that fencing can be erected below the outermost limit of the branches spread, or at a distance equal to half the height of the tree, whichever is the further from the trees.
Specification of fencing
Protective fencing should be at least 1.2 metres high, comprising a vertical and horizontal framework of scaffolding, well braced to resist impacts, supporting either cleft chestnut pale fencing or chain link fencing. Take care at all times to avoid any equipment striking the trunk, branches or foliage.
Temporary removal of protective fencing
Where protective fencing has to be temporarily removed to allow construction work to be carried out, the fence should be removed and re-erected to the maximum distance possible from the trunk immediately before the works begin. The fence should then be re-erected in its original position immediately after the works have been completed.
Storage of materials and equipment
Oil, bitumen, cement and other materials likely to damage a tree should not be stacked or discharged within 10 metres of a trunk. Materials, including soil, should not be stacked or discharged within 5 metres of a trunk. Concrete mixing should not be carried out within 10 metres of a trunk. No site huts or machinery (including cement mixers) are to be stored within 10 metres of a trunk.
Roots
If excavations find root system greater than 25 metres in diameter, the Council's planning service must be told immediately. Hand excavation should then be used to avoid damage. Roots requiring hand excavation should be surrounded with sharp sand before replacing with soil. Cement should not be placed in the vicinity of roots.
For more information:
- email: pt@renfrewshire.gov.uk
- phone: 0141 842 5811/ 5822
- fax: 0141 842 5040
- write to:
Planning and Transport
Renfrewshire House
Cotton Street
Paisley
PA1 1LL




