Engineered Timber

A variety of products is available where the timber’s natural characteristics are improved by the careful combination of different timber sections.  One of the most well-known examples is plywood, where several thin veneers of timber are bonded together.  The grain of each section runs at right angles to its neighbour, allowing for strong, large, thin and flat boards in the manufacturing process.

More recently, timber sections have been strategically bonded together where, whilst the grain direction is parallel, between adjacent ‘laminations’, the natural ‘cupping’ of the timber section is reversed.  This helps to ‘neutralise’ any effects of dimensional changes due to climate fluctuations; each lamination is affected in the usual way, but its movement is resisted by its neighbours tending to move in the opposite direction.  These characteristics are of particular importance in the production of windows and doors which are naturally exposed to climate conditions, but where dimensional stability is important for a reliable operation.

Hardwood

Oak is commonly regarded as the ‘timber of choice’ for a wide variety of hardwood applications.  In fact, there are two distinct varieties in common use:

• We typically employ European Oak for external joinery, including windows and doors; it is dense and very durable, even in damp environments.
• For interior applications, where these characteristics are less important than appearance, we normally recommend White American Oak which, as the name suggests, is a lighter-coloured timber which can have an attractive, heavily-featured grain with a warm finish.

Sapele is a reddish-brown timber and a member of the mahogany family.

• It is a strong and durable wood making it ideal for window and door applications.
• It is also fine-grained, resulting in good definition when machining finer details and offers an uniform grain pattern when stained and lacquered.

Red Grandis is a similar material to Sapele, but as less dense, it can offer advantages where weight is an issue.

Black American Walnut is dark in appearance and has a distinctive ‘burr’ type grain. It is normally used for interior joinery such as staircases, flooring and fitted furniture, where a more ‘striking’ finished appearance is required.

American Tulipwood, by contrast, is a light-coloured (almost white), open-grained hardwood; easily machined, stable and capable of achieving a fine finish and is ideal for painted interior joinery.

Softwood

Douglas Fir is the traditional softwood for British external and structural joinery.

• It is a strong, fairly dense timber, relatively straight-grained and free from knots and defects.
• It is though, a species which is becoming less commonly-available and consequently expensive.
• It is therefore reserved for use in ‘Heritage’ or Conservation Area projects, where the use of authentic materials is important.

Redwood, despite its name, is a yellow-white timber.

•  It has a straight grain, is freely machined and easily worked.
• The trees from which it is derived are amongst the largest in the world – not only extremely tall, but of enormous girth (6’ – 12’ diameter).
• It is commonly available and therefore competitively priced.
• Whilst it is not as durable and weather-resistant as Douglas Fir or some of the hardwoods described, it is nevertheless suitable (when treated with preservative and paint) for many external applications, including windows – where its open-grain structure yields an added advantage as more thermally-efficient than comparable timbers.