Choosing the right timber
Timber is still the most natural and sustainable product used in many fencing and construction projects. Choosing the correct timber species and treated to the right application, timber offers a very versatile long lasting product.
McVeigh Parker have been supplying traditional fencing timber since 1979. With over one million stakes sold annually, we are confident we can provide you with quality products, at the right price, treated to the correct user class, for your next fencing project.
Ever since the EU ban on the use of traditional treatment CCA (chromated copper arsenate) because of its effect as a toxin, a carcinogen and a teratogen, there has been a lot of questions regarding the new treatments suitability in certain timber types. It is our opinion that the only way to guarantee a suitable service life for any in ground contact timber is to use Pine/Larch (Redwood) timber only, dried and treated in accordance to BS8417. We only offer the cheaper spruce/mixed species products for those looking for short term cheaper alternative, we call these Merchantable.
UC4 15yr desired service life - timber treated to last when used in ground contact.
UC4 is what we commonly sell and would highly recommend for any in ground contact installation.
Sometimes referred to as HC4, Use Class 4 or "UC4" is the standard of treatment required for timber which will be used directly in the ground as determined by BS EN 335-1.
Can your current supplier guarantee the following?
- Redwood (Pine/larch) only used
- Packs battened between layers for better drying and treatment penetration
- Slow grown timber – as you can witness by the closer rings on the image to the right, which create a denser wood and higher mechanical properties
- Kiln dried to adequate moisture content in line with BS8417
- Pressure treated with market leading chemicals to BS8417
- Identification branded as proof of manufacturer and full traceability
- Guaranteed to give a desired service life of 15 years.
When buying timber, assurances are often put forward which state that a failing post will be replaced. The cost of a timber post is relatively small in relation to the overall cost of constructing a run of fencing when you consider labour and wire etc. The post is the vital component on which the fence is built. So isn't it better to know, correct and thorough procedure has been carried out to avoid problems with the post in the first place?
We don't offer official guarantees that some other companies may offer, these guarantees tend to come with totally unworkably restrictions such as all posts must be augured in rather than driven, drainage fillet of stone around each post, cuts and staple penetration must be post treated or percentage year on year reduction in any replacement. All these get out clauses indicate to us that there is lack of faith in the longevity of their products.
Instead McVeigh Parker will GUARANTEE that with our experience we have studied and sourced products that in our opinion, will offer a 15 year desired life. All studies highlight redwoods as the preferred in ground contact timber of choice, dried and treated correctly these should give you a reasonable service life that will match the cheapest products, when based on year on year service life.
Protect, Prolong, Progress...with our UC4 post range
Through a combination of selecting 100% Redwood Timber for in ground contact applications, sticking between layers to insure effective kiln-drying to an appropriate moisture content and penetration of a highly effective preservative treatment, we can offer high performance treated timber for all in ground contact situations.
All UC4 timber comes with a Lonza Wood Protection, Tanalith E backed 15 year desired service life to avoid premature failure from decay and insect attack.
All our timber stakes and strainers are responsible sourced from the forests throughout Europe. This includes slow grown Redwoods which when treated to our Use Class 4 standards give excellent results, even in the most challenging of environments. All the forests are responsibly managed and replanted after harvesting in line with FSC guidelines.
All our UC4 in-ground contact timbers come with a branded identification stamp to give confidence to the consumer that the product is fit for purpose. This branding gives you the customer confidence in the quality with full traceability.
The treatment process
The sample to the right has been sawn in half to check the depth of chemical penetration. Timber will expand and contract in reaction to the ambient moisture level. This inevitably leads to splits naturally occurring in the post. The crucial factor in protecting timber for a long life is to ensure all the sapwood has absorbed the treatment. This way the post is protected even when the surface opens up with splits or shakes.
By applying a copper spray re-agent which reacts to the treatment chemical, the level of penetration is highlighted as seen on the example on the right.
You can find out more about the treatment process by following this link https://www.lonzawoodprotection.com/eu/tanalith-family/
Characteristics of Timber
Wood is a natural living material and not evenly porous, not all areas of an item may dry at an even rate. This uneven drying creates tremendous pressure inside the wood which causes splits, twist or warping as its exposed to sunlight and air, more prevalent in hot summers. Wood that has been pressure treated will shrink as the water used in the treatment process evaporates from the timber. These naturally weathering characteristics are rarely detrimental to the structural strength or shorten the life expectancy of the timber.
Staining or painting the wood will increase the absorption of sunlight and speed up the drying process. Sealants and oils hold in the moisture and allow the timber to dry at a slower rate, reducing the risk of splitting.
McVeigh Parker cannot be held responsible for splitting, discoloration or warping after delivery.
Appearance and Colour
Our pressure treated timber has excellent colour retention characteristics. Its initially light green in appearance, which slowly weathers to a warm honey brown colour in external use situations, which will gradually fade to a silver grey. Further treatment or stains can be added to prolong the life and appearance of the timber. Brown available by special request.
Creosoted pressure treated timber
As with the UC4 timber standards, pressure treated creosote goes through the same process. Only selected suitable redwoods are used and the timber is dried to a moisture content of less than 28%. This age old process has long been the choice of many orchards and equestrian establishments. The life expectancy exceeds 25 years. Supplied in standard regular sizes in cundy peeled and rustic finish. Beware of cheaper products which use whitewood which will not offer the same service life.
Cost comparison – 55% more than merchantable, desired life in excess of 15 years.
English coppiced woodlands provide an annual source of fencing timbers. Chestnut coppiced in the winter will give the longest life, ideally sitting for a year then tar dipped or coated in Tuffdip. However this process is laborious and costly. Supplied in quarters, halves and full rounds mixed. Chestnut tends to be sawn rather than cleft, it then can be susceptible to splitting naturally.
Cost comparison – Equal to merchantable. Longevity, winter cut should give 15+ years.
SC4 - Sector 4
Is available as a special order product.
Merchantable Quality mixed species
A merchantable quality is a mixed species of white and redwood selected, and treated to market guidelines. Whilst every care is taken to comply with the guidelines, without the costly exercise of kiln drying it is not possible to offer a guarantee on longevity of this product. Due to market demands and competitive pressures this type of timber tends to be price sensitive and although it will suit most situations, if there is any doubt to its longevity or application then User Class 4 or Sector 4 timber should be purchased. It is Ideal for pipelines, rented ground or where initial costs is priority.
Cost & longevity comparison – competitive, longevity dependant on ground condition, timber species,
treatment process. Variable service life.
FSC – (Forestry stewardship council)
Your assurance of quality, once you have chosen your preferred timber you can be assured that all our timbers are sourced from FSC approved managed woodlands. Proof of FSC, PEFC and treatment documentation is available on request at time of ordering.