Dry British Oak
Air dried oak jointed boards VHL2
Dry British oak (Quercus species) (hardwood)
Oak grows widely across the whole of the British Isles and continental Europe and has been used in all aspects of construction, for centuries. Despite the loss of much of our native woodland, there continues to be a viable supply of British oak. We make every effort to ensure that all oak logs supplied to Vastern Timber originate from either FSC-certified woodlands or those managed under the strict guidelines of the Forestry Commission. Locally grown oak has many environmental benefits, including a reduction in carbon emissions from transport and the contributing of funds to our native forest management.
Dry oak is normally used for profiled cladding sections and is either naturally dried or kiln dried to a moisture level of 15 – 25%. A wide range of colours is common in newly machined British oak, with tones including golden honey and chocolate brown. As the cladding weathers the colour variation between the boards will decrease and they will turn natural silver.
Dry oak cladding boards are available in two formats:
1) Random length character grade boards
This type of board is suited to more rustic situations where regular knots and defects are accepted. The boards will be supplied in random lengths from 1.8mt – 3.5mt.
The knot content of these oak cladding boards will vary greatly. Boards will contain many small pin knots, small knot clusters (cat’s paws), sound medium-sized knots (up to 25mm), and occasional larger knots, some of which may split as the wood dries. Boards may also show some tight heart splits and small fissures.
2) Fixed length finger jointed boards.
These boards supplied in standard 4.0mt lengths are created by mechanically bonding a number of shorter lengths together in a high pressure press using moisture resistant glue.
The process of finger jointing oak allows us to offer cladding boards with fewer of the problems associated with oak and more of the environmental benefits that make timber cladding such an attractive building material.
Finger jointed boards are longer, less prone to distortion and of a better and more consistent quality than standard oak boards.
Utilising shorter lengths of oak allows us to increase the yield and therefore the value of the forest resource, reduce the waste in our sawmills and ensure full FSC certification for the full production. All of which is good news!
One feature of oak that must be considered is the high tannin content. During the first few years after the cladding has been attached, tannin will exude from the boards, resulting in streaks down the cladding and stains on masonry. Relative to green oak this problem will not be as severe. Tannin also corrodes ferrous metal, so it is therefore important to use either stainless-steel or at least good galvanized fixings.
BS1186-3 Class2. Grading of finger jointed oak boards
BS EN350-2 British oak is classed as durable and does not require treatment for external use, as long as the sap is excluded.
Workability: Working properties vary widely. Oak cuts well, and takes fixings satisfactorily, but can be brittle. The tannins in oak can corrode tools if not cleaned properly after use and will corrode ferrous fixings. However problems associated with tannins will be less severe than for green oak. Fixings should always be pre-drilled.
Available with FSC certification
Profiles available in British Oak