ThermoWood® Shiplap Cladding
- Profile & Coverage
- About ThermoWood
- Further Information
ThermoWood® Shiplap Profile
Silva’s ThermoWood Shiplap cladding profile is suitable for both internal and external applications. The boards interlock with a tongue and groove system for easy installation. This profile is installed horizontally to accentuate the width of the façade.
Shiplap features a curved channel along the joint that creates strong shadow lines but with a softer more sculpted appearance. The shape of the profile also enables water to run off easily.
ThermoWood Shiplap will suit a variety of applications from traditional summerhouses to striking contemporary homes.
It forms part of Silva’s range of ThermoWood cladding, boards and accessories.
What is ThermoWood?
ThermoWood is a beautiful and entirely natural wood product that is created using natural methods, the roots of which date back thousands of years. Nordic grown pine undergoes a patented natural process involving heat and steam to permanently alter its physical properties.
This thermal modification process greatly improves dimensional stability, durability and thermal insulation properties. It also removes resin and even changes the colour of the wood to a pleasing rich dark brown colour.
ThermoWood is completely natural and free from chemical additives, thus it is an exceptionally environmentally friendly building material.
There are two standard treatment classes which have been developed to take into account the key characteristics of ThermoWood. The standard treatment classes are named Thermo-S (for internal use) and Thermo-D (for internal and external use). Silva’s ThermoWood cladding is classified as Thermo-D (D stands for ‘durability’), which is recommended for end uses such as exterior cladding and decking. It has a decay resistance of durability class 2 (durable) according to the EN 113 standard which is the same classification given to Western Red Cedar.
Silva’s ThermoWood cladding is produced from high quality Nordic Pine. It is grown mainly in Finland, one of the best areas in the world for tree growth. Sub-zero winters alternate with short warm summers which results in slow growth.
The slow growth provides the best possible straight-grained timber: branches and therefore knots are few in number and those that exist are small. Growth is symmetrical and trunks are straight and round. Growth rings are thin and tightly-packed. The amount of juvenile wood is small and heartwood great. The result is a hard, tough and straight-grained timber with low internal tension. The low-resinous, evenly patterned Finnish wood is first-class material for many purposes.
This profile is available exclusively through Silva. It is sustainably sourced from well managed forests and supplied with full PEFC chain of custody certification.
The thermal treatment of wood is an ancient and natural method for improving its durability. The manufacturing process of ThermoWood is based on the use of high temperature and steam. No chemicals are used in the treatment. The process improves dimensional stability and biological durability of wood. Another improvement is in the insulation properties of the final material, the process leads to a reduction in thermal conductivity. Due to the high treatment temperatures the resin is removed from the wood. The ThermoWood treatment process is patented and the trademark is owned by the Finnish ThermoWood Association.
A Complete Range of Cladding Materials
In addition to cladding our product range includes Tyvek® breather membrane, stainless steel nails, door / window trim, soffits, fascia, barge boards, corner sections, plus a huge choice of coatings and cleaning products.
Silva Timber: A Leading Importer of ThermoWood
As a direct importer of ThermoWood, Silva can offer a wide range of ThermoWood products in large volumes as well as smaller orders. If you are a manufacturer or reseller then talk to us about your ThermoWood requirement.
20 x 118mm
Size: 20 x 118mm
Linear metres per square metre: 9.17
Silva Timber’s ThermoWood is modified to Thermo-D (Durability) standards. Biological durability is an essential characteristic for end use applications in this treatment category. The average tangential swelling and shrinkage due moisture for Thermo-D class treated wood is 5-6%, Thermo-D class ThermoWood is classified as durable according to the EN113 standard – meeting Class 2 requirements.
Key Properties of ThermoWood®
ThermoWood is a beautiful, sustainable wood material produced by using natural methods, heat and steam. Thermal modification improves the wood’s properties, thereby expanding the range of applications in which the wood can be used.
ThermoWood is dimensionally stable, resistant to decay and resin free. It can be used inside or outdoors, in any climate. ThermoWood is a non-toxic natural product which is easy to machine and install.
• Heat treatment process darkens the natural colour to an aesthetically pleasing and fairly consistent dark brown tone
• As with all softwoods, the colour consistency is affected by normal variation due to density and also depends on whether springwood or latewood is used
• Improved durability of ThermoWood (Thermo-D) makes it an excellent material for exterior uses such as decking and cladding
• Durability Class 2 (BS EN 350-2)
• Life expectancy of 30+ years (when correctly detailed)
• Standard tests (EN 113, ENV 807) made in laboratory conditions have proven a significant improvement in biological durability - a result of the removal of natural food sources in the wood and also changes in the chemical and structural composition
• Levels of resistance to fungal decay increase as higher temperatures are used
• ThermoWood is recommended to be used in hazard classes 1 to 3 in accordance with EN-335-1 without the need for any further chemical protection
• Treatment is throughout the wood piece and is not subject to leaching problems
Thermal Insulation Properties
• Heat treatment process reduces the thermal conductivity of ThermoWood
• ThermoWood has 20 – 25% lower thermal conductivity compared to untreated wood, thus giving improved insulation performance
Moisture Movement / Dimensional Stability
• Heat treatment process reduces the water uptake of wood
• Heat treatment process leads to a reduction in equilibrium moisture content (EMC)
• EMC can be 40-50 percent lower compared to untreated wood
• Heat treatment process makes it less able to absorb or lose moisture
• Restriction of moisture movement limits any potential for swelling, shrinkage or distortion
• Tangential and radial swelling decreases by as much as 40-50% compared with the original material
• Heat treatment process reduces internal stresses in timber thus reducing potential for twist and warp
• ThermoWood density is 350 - 480kg/m3 when its moisture content 6% (typical for relative humidity = 65%, temperature = 20ºC conditions).
• Material density is approximately 10% lower than the density of Scandinavian Pine
• Saws, machines and finishes well
• Heat treatment removes resin from timber. As a result there is no resin leakage or “bleed” through the surface coatings. The combined effect of this together with the improved stability can lead to a lower maintenance requirement
• As with most materials, ThermoWood is unable to resist the effects of ultra violet radiation. Over a fairly short period of time when exposed to direct sunlight, the colour changes from the original brown appearance to a grey weathered colour
• Ultra violet radiation can cause small surface shakes to occur
• Natural effects of rain and sun will cause some early wood to be removed from the surface, especially on un-coated boards, this occurs with all wood material over time
• It is highly recommended to apply a pigment based surface protection to help prevent colour changes and other natural effects of the weather
Manufacturing of ThermoWood®
The manufacturing process of ThermoWood is based on the use of high temperature and steam. No chemicals are used in the treatment. The process improves dimensional stability and biological durability of wood. Another improvement is in the insulation properties of the final material, the process leads to a reduction in thermal conductivity. Due to the high treatment temperatures the resin is removed from the wood.
The ThermoWood treatment process is patented and the trademark is owned by the Finnish ThermoWood Association.
The process can be divided into three phases:
1. Temperature increase and kiln drying
The air temperature in the kiln is raised at a rapid speed using heat and steam to a level of around 100 °C, the wood temperature follows at a similar level. Thereafter the temperature is increased steadily to 130 °C and drying takes place. Either green (unkilned) or ready kiln dried raw material can be used. Steam is used as a vapour membrane to prevent cracking of the wood. The steam also facilitates chemical changes taking place in the wood. At the end of this phase the moisture content is reduced to almost zero.
2. Intensive heat treatment
During the intensive heat treatment phase the air and wood temperature is increased to a level of between 185 – 225°C. The peak temperature depends on the desired end use of the material. When the target level is reached the temperature remains constant for 2 – 3 hours. Steam is used to prevent the wood from burning and cracking and it also continues to influence the chemical changes taking place in the wood.
3. Cooling and moisture conditioning
The temperature is reduced using water spray systems. Conditioning and re-moisturising takes place to bring the wood moisture content to a workable level over 4%.
We operate a fast and efficient timber delivery service throughout the UK, using both our own fleet and an approved 3rd party service provider. Woodcare, fasteners and accessories are all dispatched using our courier service and are available in a choice of express (2-3 days) or next day delivery.
Delivery Charges & Services
Delivery charges vary based on the products you have ordered, the location of your delivery, the value of your order and the delivery service you require.
For charges and services, please click here.
Economy Delivery Service
Our economy delivery service uses our own delivery vehicles and is available in selected postcode areas only. Orders are grouped with others within specific regions and scheduled accordingly. This allows us to provide a significantly lower delivery rate. We endeavour to despatch your order as quickly as possible, however the date can vary depending on other orders in your area, up to a maximum of 14 days. Feel free to contact our customer support team on T: 0151 541 5485 for an estimated delivery date prior to ordering.
Standard Delivery Service
If you require your order urgently we are able to deliver via an independent haulier within 5-7 working days (factory coated orders may take a little longer). Once your order has been placed online, a member of our customer support team will contact you by phone to arrange a convenient delivery day and discuss your requirements. Deliveries usually take place between Monday & Friday between 8am and 6pm.
Specialist Delivery Service
Deliveries to Northern Ireland, Orkney Islands, Argyll & Bute, Isle of Wight, the Isle of Man and Shetland Islands use our specialist delivery service. Delivery charges are calculated by the number of pallet spaces taken up by the load.
A pallet space is 1.22 metres or part thereof. The number of pallet spaces taken is determined by the longest item on the order. For example, if you order 2.44 metre long deck boards you will be charged for 2 pallet spaces.
Deliveries using this service usually take place 3 - 5 days after we receive your order (factory coated orders may take a little longer). We will contact you by phone to arrange a convenient delivery day. Deliveries usually take place Monday to Friday between 8am and 6pm.
Saturday Delivery Service
A Saturday delivery service is available on request and subject to availability (additional charges will apply). Please contact our customer support team on T: 0151 541 5485 for a quote.
Courier Delivery Service
Smaller items like screws or wood finish are delivered using a reliable express parcel service. Our standard leadtime for this service is 2-3 days. Next working day delivery is also available on smaller items ordered before 11am.
Although rare, an additional charge may be payable should the delivery company require to attempt more than two deliveries of the same order.
Deliveries are often made on large vehicles. Please let us know in advance if there are any access restrictions; for example narrow streets / farm tracks, parking restrictions, road works etc which may affect delivery. Failure to notify us, in advance, of any access restrictions may result in additional delivery charges and / or an inability to fulfil the delivery.
When Your Delivery Arrives
To keep delivery charges to a minimum, goods are manually offloaded from the delivery vehicle. Someone must be on-site to sign for the delivery and to assist with the offload. If your order contains large lengths of timber you may need additional people on hand to help. As with most companies delivering building materials, delivery obligation ends at the kerbside.
If you would prefer to arrange your own haulage or collect in person please let us know. Collection is from either our Widnes (Cheshire) or Harmondsworth (W. London) branch. We can schedule in your collection so that your goods are picked and packed in advance and our warehouse team can assist in loading your vehicle promptly.
As orders may need to be processed, picked and packed from multiple locations we are unfortunately unable to offer a 'Click & Collect' service.
Customers will be contacted to arrange a convenient date and time for collection.
Frequently Asked Questions
What time will my delivery arrive?
We appreciate that you may be taking time off work so we suggest that you request a call either on the morning of the agreed delivery date or one hour before delivery - whatever suits. Just enter your request in the 'Special Instructions' box on the order page.
What if I live outside the UK mainland?
We can arrange delivery for timber pretty much anywhere but you will need to contact us first to obtain a quote. We have successfully delivered to the Orkney Islands, Isle of Man, Isle of Wight, Jersey, Guernsey, Northern Ireland, Republic of Ireland, France, Spain (mainland), Majorca, Malta, Italy, Portugal, Gibraltar, Switzerland and Kenya. Please note we are unable to ship woodcare products to addresses outside of the UK.
Do you offer Next Day Delivery?
Next working day delivery is available on smaller courier items for UK mainland customers ordering before 11am, Monday to Friday. Next Day Delivery orders placed on weekends will be despatched on Monday for delivery Tuesday.
How soon will I receive my order?
For smaller items such as screws, nails, wood care products and shingles that are in stock, we aim to have your order with you within a few working days, with a next day delivery service available to most UK regions. Due to the nature of our larger items, such as deck boards, cladding and fencing, our picking and delivery times can vary. Once your order is placed a member of our sales team will contact you to arrange a suitable and prompt date of delivery.
What happens with my order?
Once an order is placed, it is keyed into our CRM system and added to the schedule for the operations team to pick. Customers are contacted the day after their order is placed to arrange a convenient delivery date.
Once picked, the order is then packed and tightly shrink-wrapped to ensure secure delivery.
We aim to dispatch orders from our warehouse to our delivery partners within 2-3 days, providing a rapid turnaround for customers.
Customers are called on the day of their delivery with an estimated time of arrival.
We’re confident that the products and service you receive from Silva Timber are of the highest quality. We consistently receive positive feedback from customers and love to see how our timber has been used for projects both large and small. Feel free to contact us at any time with news of your build or for any further advice.
Fire Retardant Treatment
This product is PEFC certified.
PEFC (Programme for the Endorsement of Forest Certification) is an independent, non-profit, non-governmental organisation founded in 1999 which promotes sustainably managed forests through independent third party certification. The PEFC provides an assurance mechanism to purchasers of wood and paper products that they are promoting the sustainable management of forests.
PEFC works throughout the entire forest supply chain to promote good practice in the forest and to ensure that timber and non-timber forest products are produced with respect for the highest ecological, social and ethical standards. Thanks to its eco-label, customers and consumers are able to identify products from sustainably managed forests.
Silva Timber meets the requirements for PEFC Chain of Custody within the BM TRADA Certification Limited Scheme for TRADA - Trak chain of custody certification.
Certificate number: BMT-PEFC-0319
Expected Service Life
TRADA Durability Class: 2
TRADA Moisture Movement Class: Small
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