Sweet Chestnut for external timber cladding

It's true that when it's fresh sawn Chestnut's hard to tell from Oak. It has a similar colour, maybe due to the Tannin content (like Oak) but when it dries it's quite different. You wouldn't normally have trouble telling the two wood species apart.

Dry, the colour is creamier than Oak, with sometimes contrasting brown streaks than you wouldn't see in Oak  and sometime some strong yellow colour.

Chestnut grain is a real feature. It's open, fairly coarse, great for wide expanses - a bit like Ash or Elm in that way - and is fairly dense.

It's a strong and durable timber so it's great for cladding as well as other external uses and the Tannin content gives it inherent durability.

Like other fresh sawn products, Chestnut will take a finish when it's surface dry if you want to stop the weathering and silvering process, otherwise it will grey down over time and doesn't need any preservative treatment.

When it's dry and machined Chestnut will take finishes as any other hardwood, although it's always worth checking products are compatible with Chestnut and that it doesn't contain strong alkali (eg.ammonia) which will react chemically and darken the colour. 

Watch the video for an  Introduction to Sweet Chestnut

Sweet Chestnut PRIME* Grade specification (qualities that determine the grade)

Watch Tom's video on Sweet Chestnut Grades

Fully and partly inter-grown knots: one ?20mm diameter or several smaller up to a combined diameter of 20mm

Non inter-grown knots and rotten knots: occasional if measured-out

Checks: occasional surface + occasional splits in sound knots permitted

Shake: no

Colour: none specified but surface stains are not generally regarded as a defect providing that they do not penetrate into the timber. Sticker-marks and other penetrating stains are not permitted in grade 1 pieces and may be excluded in grade 2.

Grain: straight or nearly straight + wavy-grain is accepted providing that it can be regarded as a special decorative feature that will not limit the performance of the piece in its intended use.

Bark: no

Rot / insect attack: no

Warp: none specified

Wane: none specified

Sapwood: should be excluded if used externally

*Grade 1 as defined by Making The Grade

Finger-jointing describes that process of end-joining longitudinal lengths of timber using a fine zig-zag or toothed profile that appears as linterlocked 'fingers' on the smooth finished surface.

It's mainly produced using short lengths as part of waste recovery that has inherent benefits. The pre-machined long lengths enable a faster, more regularised installation. The recovery of the short lengths maximises the timber as a resource and keeps wood waste to a minimum which is an inherently sustainable practice.

French Sweet Chestnut is generally, and has been historically, grown in the south east, and in lesser numbers in the south west, of France in the Occitanie region up into the Auvergne and across through the Provence Alpes and Cote d'azur. It doesn't do well in heavy clay soils or high levels of moisture but having origins in southern europe it's a tree species with resilience and characteristics suitable  for adaption to changes in climate and global warming. This timber has strong sustinability credientials as a choice  for furniture, joinery, cladding or structural work.

Watch Tom's video on the sustainable sourcing of Sweet Chestnut.

PEFC Certified Timber

PEFC is an an international non-profit, non-governmental organization dedicated to promoting sustainable forest management through independent third-party certification. They operate as a global alliance of national forest certification systems.

Our PEFC Chain of Custody

We hold chain of custody timber certification for Programme for Endorsement of Forest Cerification (PEFC) schemes  CU-PEFC-805623 which accompanies our structural timber including the fresh sawn oak beams and posts and the seasoned stock.

Downoad a copy of chain of custody certificate here

Here are some links to information on cladding, Chestnut or timber in general that we hope will be useful or interesting;

See our Chestnut stock

See more CLADDING products

Read more about Sweet Chestnut

Blogs about Chestnut Cladding

Read about Tannin in timber

Tom's video about harvesting Chestnuts to eat

Download a copy of MAKING THE GRADE - grade specifications

Get useful timber Cladding resources on the TRADA website

Read about timber cladding in buildings & architecture on Dezeen

More about PEFC timber certification