Treated Timber Q and As

Below are just some of the regular questions we get asked about our TANALISED and TANATONE preservative treatments for timber.

What are the recommended areas of use for TANALISED / TANATONE pressure treated timber?

TANALISED pressure treated timber is designed for a wide range of end uses from internal building timbers through to external timbers in ground or fresh water contact. These are classified as Use Classes 1-4 as defined in BS EN 335-1. TANALISED pressure treated timber has a natural pale green colouration that blends perfectly with outdoor environments.

TANATONE pressure treated timber with a built-in brown colouration is recommended for fencing and landscaping timbers – Use Classes 3.2 & 4.

Can I use TANALISED pressure treated timber around my fish pond?

TANALISED pressure treated timber is suitable for use in, around and over garden ponds. However, where fish are present we recommend that direct water contact is avoided.

Whilst we are confident about the safety of TANALISED pressure treated timber, fish are very sensitive creatures and may respond unfavourably to changes in their surroundings.

Prior to use, you should ensure that the timber is in a dry condition; two weeks post treatment is usually sufficient time to allow for drying although this is weather and storage condition dependent. Please also ensure that the timber you use has been treated to the correct specification – if the timber is to be used above ground (Use Class 3) and if it is to be used in ground (Use Class 4).

Please see our Treated Timber User Guide for more information on the use of TANALISED pressure treated timber.

Can I use treated timber for making bat shelters?

Bat roosts and shelters are closely protected by conservation legislation. You must consult the Statutory Nature Conversation Organisation for your area (Natural England, the Countryside Council for Wales, Scottish Natural Heritage) before doing anything.

The Bat Workers’ Manual published by the Joint Nature Conservation Committee provides initial guidance. It can be downloaded from: http://www.jncc.gov.uk/page-2861 or ordered from: NHBS Ltd, 2-3 Wills Road, Totnes, Devon TQ9 5XN

The Bat Workers Manual recommends the use of pre-treated timber therefore we can confirm that it is safe to use TANALISED E treated timber.

Can TANALISED or TANATONE pressure treated timber be use for the construction of bee hives?

TANALISED or TANATONE pressure treated timber is suitable for use in a bee hive. However, you should not use it for internal elements of the hive that will come into direct contact with honey.

Prior to use, you should ensure that the timber is in a dry condition; two weeks post treatment is usually sufficient time to allow for drying although this is weather and storage condition dependent. Please see our Treated Timber User Guide for more information on the use of TANALISED pressure treated timber.

Is TANALISED pressure treated timber safe to use in nature reserves and aviaries?

TANALISED pressure treated timber is suitable for use on a nature reserve or for constructing aviaries.

Prior to use, you should ensure that the timber is in a dry condition; two weeks post treatment is usually sufficient time to allow for drying although this is weather and storage condition dependent.

Please see our Treated Timber User Guide for more information on the use of TANALISED pressure treated timber.

I am doing a COSHH assessment on the treated timber we stock. Can you send me a material safety data sheet for your preservative products?

The Control of Substances Hazardous to Health (COSHH) Regulations refer to substances. Preservative treated timber is not a substance but an article and therefore COSHH regulations do not apply to the actual treated timber. A ‘COSHH and treated timber’ information sheet does provide more details relating to this classification.

The preservative treated timber should be delivered to you in a surface dry condition. This is safe to handle as recommended and can be handled in the same way as untreated timber.

The document below, which provides health and safety handling recommendations, may also assist in carrying out your COSHH risk assessment:

Treated Timber User Guide for more information on the use of TANALISED pressure treated timber.

What happens to the preservative protection when treated timber is cut or notched?

Ideally timber should be cut or notched before treatment. However, where these procedures are required on-site, the surfaces exposed by the cutting or notching of TANALISED or TANATONE treated timber should be further protected with an approved brush-on end grain preservative to maintain the integrity of the preservative protection.

How do I dispose of TANALISED / TANATONE treated timbers and can they be incinerated?

The concentration of the hazardous components in both TANALISED and TANATONE treated wood waste is below the European Waste thresholds and therefore both wastes are not hazardous. Processing wastes, such as sawdust and off-cuts, must not be used for animal litter or bedding. Preservative treated timber should not be used as a fuel in barbeques, cooking stoves or grates.

Generally, small quantities (less than 0.5 tonnes) can be burnt at any one time in the open, providing the fire is positioned to enable adequate dispersal of the smoke. The residual ash is non-hazardous. However, due to a few recent developments from some local councils under the Environmental Protection Act 1990, we would recommend that consultation should be made to these regulations, and preferably to the local enforcement agency, before burning any waste on site.

Householders should dispose of the timber or sawdust through the ordinary waste collection service or at local authority amenity/disposal facilities.

Any waste timber, sawdust or redundant timber from commercial or industrial use (e.g. construction sites) should preferably be recycled by re-use or disposed of to an authorized landfill or to a correctly controlled and approved waste contractor.

Is TANALISED pressure treated timber safe to use in children’s playgrounds?

TANALISED pressure treated timber is safe to use for structures in and around children’s play areas.

With regard to any concerns that the children may ‘chew’ or ‘eat’ the treated timber, safety studies have been conducted to demonstrate safe use of our products as part of their approval process. These studies have shown that the preservative within the timber would not cause harm to a child in the quantities that they are able to ‘eat’ or ‘chew’.

Prior to use, you should ensure that the timber is in a dry condition; two weeks post treatment is usually sufficient time to allow for drying although this is weather and storage condition dependent.

Please see our Treated Timber User Guide for more information on the use of TANALISED pressure treated timber.

Is TANALISED pressure treated timber safe to use for compost bins and earth retaining structures for organic vegetable beds?

TANALISED pressure treated timber is suitable for the construction of compost bins and for use as earth retaining structures for organic vegetable beds. The Soil Association – www.soilassociation.org. states that if the timber used for organic vegetable beds is preservative pre-treated then there are no issues in terms of organic status. If, however, the wood is treated once the raised bed has been built (brush applied preservative) then this would effect the status of the land.

Prior to use, you should ensure that the timber is in a dry condition; two weeks post treatment is usually sufficient time to allow for drying although this is weather and storage condition dependent. Please see our Treated Timber User Guide for more information on the use of TANALISED pressure treated timber.

Can zinc or hot dipped galvanised sheeting be used in contact with TANALISED pressure treated timber and what fixings are recommended?

Pure zinc or hot dip galvanised sheeting can be used in contact with TANALISED pressure treated timber used in dry internal situations or where the moisture content of the timber will not exceed 20%. There may be some tarnishing and if the sheet is galvanised, the zinc coating may become damaged, increasing the possibility of corrosion.

Where the moisture content of the timber is likely to exceed 20%, contact areas between the metal and timber should be separated where condensation is possible using a bituminous, epoxy or other impervious barrier or electrically insulating coating. The use of nylon/plastic washers or other insulating physical spacing barriers is recommended.

It is important to attach the sheeting and any fasteners after preservative treatment and only when the timber has re-dried to less than 20% moisture content. The zinc sheeting should be of a quality suitable for the intended end use situation. It is also important that sheeting and fasteners are compatible to prevent bimetallic corrosion; for example do not mix galvanised and stainless steel components.

Any fixings used should of a quality that is consistent with the end use. We generally recommend hot dipped galvanised as a minimum standard. Electro galvanised components are not recommended for external use.

We would advise that you always contact the suppliers of connectors, fasteners and sheeting or roofing for specific recommendations about their particular grade of product.

Please note that there are many thicknesses of galvanised coating available and the thicker the galvanised coating the longer the expected service life of any metal system. Performance of metal fixings is influenced by the environmental conditions including moisture content, temperature, atmospheric pollution, proximity to coastal locations and timber species as well as the thickness of any zinc coating and it is impossible to accurately predict the service life of any specific installation.

Please see our Treated Timber User Guide for more information on the use of TANALISED pressure treated timber.