Glulam Timber Species
The most common timber used in the manufacture of glulam is Spruce, followed by European Larch, Siberian Larch, Douglas Fir, European Redwood (Scotts Pine) and Oak. We are always looking to try other species or timber types, examples include Iroko, Accoya and recently we have had good results with trials of the UK grown Ash and Sweet Chestnut.
It is sometimes quite easy to forget that timber is a natural product – it varies in colour texture and grain. Even a single plank of wood visually changes greatly across its length. It is a beautiful, natural product and when adopted within a building it can bring a natural resonance second to no other material.
Wood has been used in some of the largest construction projects in the world and adopted for use in the smallest utilitarian tools (from toothpicks to matches). It is a sustainable, versatile material and its use and application have helped to shape history – from bridges and boats through to arrows and pencils! Its application affords an unmatchable natural resonance, and it continues to enhance both the smallest of interior spaces and the largest exterior projects worldwide.
There are over 60,000 different species of trees on the planet. Some differ in such small ways that are hardly discernible to the naked eye whilst others are worlds apart. Even with this huge variety to choose from we predominantly use only five different varieties: Oak, Larch, Douglas Fir, Spruce and Redwood. Their characteristics differ greatly but we have found this small combination can provide the widest possible option when used in the manufacture of glulam beams.
We are often asked to send out samples of glulam – softwood varieties are usually free of charge. If you wish to receive a specific timber sample discuss your requirements with Tasha by telephone on 01363 891 363 or if you email: email@example.com
A summary of some of the attributes and uses for the most commonly used species is given below.
Attributes, characteristics and use
The embodied energy of timber is much lower than most alternate construction materials such as concrete and steel. With considered forest management, timber can be easily sustained and readily available worldwide. Being a very popular choice of building material, timber has great properties of strength, is lightweight, reliable, durable, and versatile. It has an incredible strength to weight ratio, twenty percent higher than structural steel and four to five times better than un-reinforced concrete when used in compression.
Glue laminated timber builds on the inherent strengths of timber whilst increasing the dimension, complexity of beam shape and size.
Perhaps with this in mind, glulam is becoming the go-to sustainable option for growing numbers of contemporary architects and designers.
Spruce is the most cost-effective and readily available timber for glulam manufacture. For any project where large quantities are required or the lowest price possible in glulam is wanted, Spruce will be the timber of choice for the glulam. Depending on the quantity required, it is likely that we would source this from German factories that specialise in mass production in this material.
Also called Whitewood, Spruce is widely distributed throughout continental Europe and is a species of major economic importance. The large, fully grown trees usually have a straight trunk and grow to a height of about thirty meters, (the largest examples up to 55-metres). On average it is felled when its diameter measures around sixty centimetres. If left it can grow up to 1.5 meters.
Its colour ranges from a creamy white, light yellow to a reddish-brown. The heartwood is not distinct from its sapwood. It is straight-grained with thin and regular texture. The timber can emit sap even after being seasoned and machined. The wood is soft, easy to manipulate and work, low in weight and has a medium density. The strength properties are good, it is most commonly used in construction for both structural and internal joinery (skirting boards, architraves, etc.). It is an ideal choice for machining and structural application.
PORTFOLIO: Click to have a look at one of our Spruce projects.
Siberian Larch is usually fairly clear of knots and can provide a good option when something with a little more character than standard Spruce is required. All our Siberian Larch glulam is currently produced in house.
It is classed as moderately durable and can be used in locations exposed to weather conditions (if suitably treated). It is a heavy and hard coniferous wood. The fairly thin sapwood is light-yellowish to reddish-yellow. The heartwood reddish-brown to glowing red when fresh, darkening to gold-brown. It has a clearly striped or grainy patterning. When exposed to natural light, Larch will eventually lose its natural colouring turning to a silver-grey. Siberian Larch is a frost-resistant tree native to Western Russia. It is very slow grown with dense growth rings. It can be factory coated in SiOO:X, a breakthrough water-based silicone technology, to provide a genuine silver lustre. The treatment creates a weathered appearance at an accelerated rate. Following application, regardless of protection and exposure, the timber takes on a consistent tone which provides a solution to differential weathering whilst strengthening the timber’s surface and creating a water repellent layer.
PORTFOLIO: Click to have a look at one of our Siberian Larch projects.
As with Siberian Larch, Douglas Fir can provide a more characterful option to Spruce. It can be used externally (if suitably treated and maintained) with a recommendation to use sapwood free Douglas Fir. We manufacture glulam in house from both UK grown and imported French Douglas Fir. We also occasionally use almost knot-free North American Douglas Fir when a high specification finish is required.
Douglas Fir originates in the North West of America. It was introduced 200 years ago into the UK and Europe as a fast-growing sustainable timber primarily for use in construction. Properties of European Douglas Fir (mostly relating to the speed of growth and grain size) differ depending upon altitude and weather conditions – colder the climate, closer the grain.
The heartwood has a pinkish to dark red colour and is clearly discernible from the yellow sapwood. The sapwood has a thickness of between five and ten centimetres. The texture of the timber is medium, it has a fairly straight grain with the light and darker colours differing in terms of hardness. It can show some resin pockets (sometimes in large sizes). The timber has a medium-density and good strength properties. Glueing and sawing properties are good, as well as nailing and screwing, but pre-drilling is necessary as there is a strong tendency for splitting.
PORTFOLIO: Click to have a look at one of our Douglas Fir projects.
Redwood has the advantage that it is widely stocked in the UK at a low moisture content for joinery purposes, which also suits the requirements of glulam manufacture. It is also available in a range of quality gradings which mean it is easier to produce knot-free or nearly knot-free glulam with Redwood than with Spruce. The cost of the timber is similar to Spruce.
Redwood (Pine) – or also called Scots pine, has a growth range larger than that of any other softwood. It can be found from Scotland to the Pacific Coast of Siberia, Norway, Mongolia and also in the Mediterranean region. The trees grow from ten to thirty meters tall, with the largest sizes being up to forty meters in height. Scots pine from the Nordic countries is used for construction with large volumes of timber being produced in Scandinavia for housing. We often use Pine for our glulam as it is readily available in joinery (or ‘unsorted’) grade which is relatively knot-free.
Pine has distinct yellowish-white sapwood and reddish heartwood. Heartwood is clearly recognisable from the sapwood. Slow grown Nordic pine is very easy to machine to a smooth surface. Knots are tightly fixed in the timber and normally limited in size. The big red knots are common and give a decorative character to the timber. The wood is soft, medium in weight and has a medium density. The strength properties are good. Sawing and machining are easy, glueing can at times be difficult depending on the percentage of resin in the wood. In the UK it is mostly used for construction and also for joinery, interior finishing and furniture.
PORTFOLIO: Click to have a look at one of our Redwood (Pine) projects.
European Oak is an exceedingly strong, heavy and durable timber. It has an attractive light colour with a prominent grain. It is resistant to fungal attack, thanks to its dense constitution and long-living nature. Oak is slow-growing, very dense with a tight grain. It has been harvested and used in a wide variety of applications from joinery, large construction timbers through to barrel making, bowls and small decorative household items.
Our use of Oak glulam is predominantly for small scale house extensions where high quality is required. We usually use prime grade Oak boards for our glulam, meaning that although the material is a little more expensive, the finish and quality is guaranteed.
Please note: Oak glulam does not carry a CE strength certification grade as it is not included in the CE glulam standards. We recommend designing to GL24 grade for our Oak glulam beams. Oak is a natural material – it comes in a broad range of colours and tones. We cannot offer or guarantee uniformity throughout the wood, only the physical integrity of each component.
PORTFOLIO: Click to have a look at one of our European Oak projects.
If you have any questions about a timber species or would like to visit our workshop and see some timber at first hand contact Keith at Buckland Timber by email: firstname.lastname@example.org or by telephone on 01363 891 363.