• Nominally: 25mm x 145mm 
• Finished depth: 18mm 
• Face cover: 135mm   
• Dark brown colour due to heat preservation process
• Naturally waterproof ready for immediate use no treatment required
• Contemporary looking 
• Long service life

Wastage Allowance:

• We advise over ordering by 10%, our ThermoWood is quality checked and its premium industry standardized grade is 5ths & btr excl 6ths.
• No more than 10% of the boards may contain workable naturally occurring defects such as minor surface splits, end splits, and even occasional dead knot holes but in no more that 10% of boards received. Knots that are sound but cracked are characteristic of this product and not classed as defects.

Fixing Types:

All screws, nails, bolts and metallic accessories that come into contact with this product must be corrosion resistant. We recommend:

• Stainless steel

If fixings other than stainless steel are used there is risk of permanent spotting and corrosion stains appearing on the surface. This is due to naturally occurring acidic oils.

Should I use screws or nails for fixing?

• Thermowood cladding can be fastened using annular ring shank nails or lost head nails for a more discreet appearance. Screws are also suitable. Fixings should sit flush with the surface, avoid countersinking or punching below the surface to prevent splits and head pull-through.

What size Screws or nails do I need?

• Ring shank or lost head nails should be a minimum diameter of 2.0mm.
• Screws should be a minimum diameter of 3.5mm – pre drill pilot holes 2/3rds of shank diameter to minimize risk of splitting.
• Minimum length of nails and screws should be the depth of the cladding plus at least 25mm.

Installing ThermoWood cladding:

• Our ThermoWood is supplied heat treated to a moisture content below 10%, meaning no drying is required prior to installation, its ready for immediate installation, even inside saunas.
• Fixing through the face is most secure.
• If board is below 100mm in width insert one centrally placed fixing at every batten.
• If the board width ranges from 100mm to 200mm wide, insert two fixings where the board crosses a batten, positioning the fixings approximately 25mm to 50mm from the board edges.
• Cladding profiles with hidden nail recesses exceeding 100mm in width, should have one fixing inserted into the face spaced approx. 25 – 50mm from the groove and another fixing inserted at an angle into the hidden fixing recess next to the tongue.
• It is not recommended to completely hide the fixings. Instead, ensure your cladding is securely and properly fitted by following this guidance.
• Battens external cladding is fitted to should be treated to protect your structure from moisture.
• ThermoWood should be secured to battens, battens can be drilled secure to a brick wall using 6mm masonry drill bit and matching screw plugs. Battens can also be screwed using pilot holes into plywood sheets.
• Do not secure ThermoWood cladding directly to plywood or sheet materials.
• Exposed end grain of boards should be protected with either trims, metal capping or end grain sealant.
• Optional, leave a 175mm gap between the ground and the cladding to prevent the bottoms of the boards from being exposed to ground level moisture, dust and general splatter.
• For horizontally installed cladding battens should be vertically installed.
• For vertically installed cladding battens should be horizontally installed.
• Fixing centres should be a maximum of 600mm apart.
• Batten material should have the same service live as the cladding being chosen, we advise battens used are graded and are pressure treated.
• Minimum batten or lath dimensions should be 50 x 38mm or 50 x 25mm if being counter battened.
• L shaped trims are intended for use on external and internal corners, as well as door and window surrounds, L shaped trims are also used to achieve straight horizontal and vertical lines where minute differences in cut cladding length would be otherwise noticeable.
• In the absence of ThermoWood L shaped trims it is also possible to miter joint two pieces of planed square edge timber together, PSE can be created with an on site table saw, cutting edges on a 45° angle, edge glueing and pinning secure.  
• ThermoWood is dry and ready to absorb aftermarket oils and coatings.
• If staggering runs together, ensure they are jointed on battens and also edge glued together to prevent separation and end grain water splotching.

Cavities:

• Cavity ventilation barrier of 10mm or more is required to prevent long term moisture build up. Fixing your ThermoWood cladding to battens as per above guidance will achieve this. 
• Metal vermin mesh should be fitted at all cavity entrances
• Optional; breather membrane to be fitted to ply / brick wall battens are secured to, for added moisture protection, (is essential in saunas.)

• Goods are manually offloaded by our hauliers to the kerbside, or delivered in secure boxes to your front door.
• Protective sheets can be supplied with timber if you plan to store outdoors for extended periods of time, please let us know.
• Air drying sticks and be sent with your order free of charge if you plan to season your timber, ie for saunas or places where low moisture content is important.
• Please let us know if heavy goods vehicles are not suitable for your access.
• You will receive notice 1 hour before delivery to ensure someone is present to accept and sign for delivery.
• Standard delivery is usually made within 3 working days.
• Express delivery is usually next day but can sometimes take 2 working days.
• Please note our online checkout is currently unable to correctly price delivery if you are located in any of the below locations, please contact us for the right price.

• All UK isles, Scottish Highlands, North East Scotland, Cumbria, Durham, Tyne and Wear, North Yorkshire, Lancashire, Cornwall, Devon, Kent, East Sussex, Gwynedd, Pembrokeshire, Carmarthenshire, Ceredigion. ​

• We understand making a large online purchase is a big decision. That's why we offer a flexible returns policy to guarantee your satisfaction. 

• Our team prioritizes complaints and will usually respond with an agreeable solution within a couple of hours. We want you to be completely satisfied with your purchase, we'll do our best to make it right. We want you to tell others about our good service and continue using us for future projects.

• If for any reason you are not completely happy with your purchase, you can return it to us within one month of delivery. Orders can be returned even if nothing is wrong, or if you have simply changed your mind. However, please note that in such cases, the transport cost will be deducted from the refund amount.

• All orders are quality checked prior to being dispatched, nevertheless in the unlikely event your order has a larger ratio of imperfections than set our in our description’s, we will offer to swap the lengths in question and we will also offer a full refund including all transport costs.

• If you would like to return an order that is showing signs of use or damage not caused by us, ie, lengths cut down, continuing nails, paint or oils, or spoiled timber due to being stored outside unprotected. If you find yourself in this predicament we will still accept return of the timber and will have to assess its new condition and negotiate a reasonable refund offer for you.

• Refunds are issued within 48 hours or timber being returned and checked, trade customers can have opt for credit notes.

• Applying preservatives to externally installed ThermoWood is optional. In order to enhance the natural appearance and to delay the silvering process we advise using a quality protection oil such as Osmo 010 ThermoWood this oil is suited for all types of ThermoWood including cladding and decking. This will slow the weathering / silvering process as well as enhance your product. Re apply every 2 – 3 years to maintain enhanced natural appearance indefinitely.
• Once your cladding has eventually silvered you may like the silver colour as many customers do, some customers achieve this faster by applying weathered aged wood accelerator for a unique and sort after natural worn aesthetic.  
• If you want to revive your timber once silvered off there are numerous solutions that will bring your timber back. Depending on how weathered your wood is you may be able to apply wood stain straight onto it, try sampling a small section to see.
• If your species is vulnerable to fungal attack we advise mixing Owatrol VC175 Mould Killer a powerful internal and external anti fungal additive mixable with any oil, varnish lacquer, wood stain or paint, simply mix with your preferred coating for lasting protection. Note: ThermoWood is not vulnerable to fungal attack it naturally resists fungus.
• If your wood is heavily weathered, we advise using a power washer after scrubbing the wood with a mixture of water and bleach. Though labor-intensive, this process is cost-effective. Ensure you wear appropriate personal protective equipment. This method is also effective for removing algae, mildew, and fungus. After cleaning, apply protective oils, lacquer, and stains for long-lasting protection and satisfaction with your wood. Do not power wash softwoods with a finished depth of less than 18mm. Avoid positioning the water jet close enough to damage the timber.

• ThermoWood does not require stickering or acclimatizing since it Is already thoroughly dried out in production.
• Please contact us before delivery to ensure you are prepared. If anything is not right, submit a complaint immediately, and we will be happy to assist.
• Its advised to store your timber either indoors, or outside under ventilated and weighed down tarpaulin sheets and or in a shaded area where the elements cannot reach your wood.
• If you decide to sticker your order, the sticks for drying on site must be clean and ideally planed to minimize marks. Any faint marks caused by stickering will fade away over time.
• Timber should be stored raised above ground.