Preservative Treatment
With excellent links to a number of local timber treatment plants we can offer a wide range of processes including preservative and fire retardant systems. Information on treatment selection based on end use and desired service life together with data sheets are available via links on this website. We have even included a short video on a High pressure treatment process.
Koppers Performance Chemicals (formerly Osmose)
Low Pressure Sentrin Preserve E406*
Colour: Clear/Yellow - Use Class: 1 & 2
*NOTE: This treatment is often referred to as “Double Vacuum” relating to the double vacuum process described below.
Available to order typical lead time 3-7 days
Treatment specification summary
Sentrin Preserve LP (low pressure) treated timber provides long term protection against fungal decay and insect attack. It is suitable for use in weather protected applications above damp course such as timber frame construction, roofing timbers and coated external joinery components. Timber is treated under vacuum and low pressure to achieve a penetration and preservative retention specification. The service life is dependent on the species, moisture content and intended end use.
Treatment Process
Treatment is carried out in a low pressure autoclave to force preservative into the timber to provide an “envelope” of protection. Timber is loaded into the treatment tank and the door sealed. A vacuum is then created inside to remove the air from the timber. The vessel is then flooded with preservative penetrates at least 3mm into the timber. After the solution is removed a final vacuum is created to remove excess preservative. The timber is then stored undercover until dry when it is ready for collection or despatched. Typically the treatment process takes 45-90 mins with a lead time of 3-7 days depending on workload.
High Pressure AC500 Naturewood
Colour: Green - Use Class: 2, 3 & 4
Standard sizes held in stock otherwise available to order typical lead time 4-5 days.
Treatment Specification Summary
Sentrin Preserve HP (high pressure) treated timber provides long term protection against fungal decay and insect attack. It is suitable for use in external applications such as fencing, decking, landscaping and structural components. Timber is treated under high pressure to achieve a penetration and preservative retention specification. The service life is dependent on the species, moisture content and intended end use.
Treatment Process
Treatment is carried out in a high pressure autoclave to force preservative deep into the timber for long lasting protection. Timber is loaded into the treatment tank and the door sealed. A vacuum is then created inside to remove the air from the timber. The vessel is then flooded with preservative penetrates at least 3mm into the timber. After the solution is removed a final vacuum is created to remove excess preservative. The timber is then stored undercover until dry when it is ready for collection or despatched. Typically the treatment process takes 90-300 mins with a lead time of 3-7 days depending on workload.
High Pressure AC10
Colour: Green - Use Class: 2, 3 & 4
Standard sizes held in stock otherwise available to order typical lead time 4-5 days (UC3 special order)
Treatment Specification Summary
Sentrin Preserve HP (high pressure) treated timber provides long term protection against fungal decay and insect attack. It is suitable for use in external applications such as fencing, decking, landscaping and structural components. Timber is treated under high pressure to achieve a penetration and preservative retention specification. The service life is dependent on the species, moisture content and intended end use.
Treatment Process
Treatment is carried out in a high pressure autoclave to force preservative deep into the timber for long lasting protection. Timber is loaded into the treatment tank and the door sealed. A vacuum is then created inside to remove the air from the timber. The vessel is then flooded with preservative penetrates at least 3mm into the timber. After the solution is removed a final vacuum is created to remove excess preservative. The timber is then stored undercover until dry when it is ready for collection or despatched. Typically the treatment process takes 90-300 mins with a lead time of 3-7 days depending on workload.
High Pressure Celcure Bronze
Colour: Brown - Use Class: 2, 3 & 4
Treatment Specification Summary
Sentrin Preserve HP (high pressure) treated timber provides long term protection against fungal decay and insect attack. It is suitable for use in external applications above damp course such as fencing, decking, landscaping and structural components. Timber is treated under high pressure to achieve a penatration and preservative retention specification. The service life is dependent on the species, moisture content and intended end use.
Treatment Process
Treatment is carried out in a high pressure autoclave to force preservative deep into the timber for long lasting protection. Timber is loaded into the treatment tank and the door sealed. A vacuum is then created inside to remove the air from the timber. The vessel is then flooded with preservative penetrates at least 3mm into the timber. After the solution is removed a final vacuum is created to remove excess preservative. The timber is then stored undercover until dry when it is ready for collection or despatched. Typically the treatment process takes 90-300 mins with a lead time of 3-7 days depending on workload.
Lonza Wood Protection
Tanalith E
Colour: Green – Use Class: 2, 3 & 4
Treatment Specification Summary
Tanalith E pressure treated timber is timber which has been impregnated with TANALITH E wood preservative under controlled conditions in a vacuum pressure timber impregnation plant.
BASF Wolmanit
Wolmanit CX
Colour: Green - Use Class: 2, 3 & 4
Standard sizes held in stock otherwise available to order typical lead time 4-5 days (UC3 special order)
Treatment Specification Summary
Wolmanit CX is a wood preservative for industrial use against wood destroying fungi and insects on internal and external structural timber with and without ground and water contact, in particular for timber used in horticulture and landscape gardening, playground equipment, posts, vine support, fences, palisades and wood paving.
Treatment Process
Treatment is carried out in a high pressure treatment tank using a double vacuum process.
Initially after treatment, timber has a green appearance which after weathering will gradually change to a warm brown colour.
Use Class Guide
| Use Class | Typical service situation | Service Life |
|---|---|---|
| Use Class:1 | Typical service situation:Above ground covered. No risk of wetting | Service Life: Up to 60 years |
| Use Class:2 | Typical service situation:Above ground covered. Occasional risk of wetting | Service Life: Up to 60 years |
| Use Class:3a | Typical service situation:Above ground coated. Exposed to frequent wetting | Service Life: 30 years |
| Use Class:3b | Typical service situation:Above ground uncoated. Exposed to frequent wetting | Service Life: 15-30 years |
| Use Class:4 | Typical service situation:In contact with ground or fresh water | Service Life: 15-30 years |
| Use Class:5 | Typical service situation:Permanently exposed to wetting by salt water | Service Life: N/A |
| Use Class: | Typical service situation: | Service Life: |
| Use Class:1 & 2 | Typical service situation:Internal construction timber, timber frame, floor joists, sole plates above DPC & internal cladding | Service Life:60 years |
| Use Class:3 | Typical service situation:Fence rails, deck boards & garden timber. Exposed cladding, soffits, fascias & Sole plates above DPC. | Service Life:15 to 30 years |
Brief guide to timber preservation
Key Points
- Treatments provide resistance to rot & “woodworm”
- Although treatments are applied under pressure the chemicals may only penetrate around the outside of the timber forming a “skin” or envelope
- Timber species take up preservatives at different rates
Preservative penetration & solution levels depend on the end use of the timber - Desired service life reflects the penetration level for example roof battens requires little or no penetration to achieve 60-year service life. Fence posts however require a minimum 6mm penetration to achieve 15-year service life.
- Some species are resistant to pressure treatment e.g.spruce & douglas fir which limits the penetration levels unless additional processes are applied such “incising” etc.
- Even when service life is specified not ALL pieces within a batch will meet life expectancy a few will decay earlier but the treatment process is still deemed sound.
Click Here for a guide on how to buy & specify preservative treated wood.
Use Class Guide
| Use Class | Typical service situation |
|---|---|
| Use Class :1 | Typical service situation:Internal, with no risk of wetting |
| Use Class :2 | Typical service situation:Above ground with occasional wetting |
| Use Class :3C | Typical service situation:COATED Above ground exposed to frequent wetting |
| Use Class :3U | Typical service situation:UNCOATED Above ground exposed to frequent wetting |
| Use Class :4 | Typical service situation:Ground contact permanently exposed to wetting |
| Use Class :5 | Typical service situation:Permanently exposed to salt water wetting |