14×12 The Martel | 44mm Log Cabin

1. Untreated: Any wooden structure that is left untreated will have its lifespan dramatically shortened. This is especially the case with Douglas fir or European softwoods such as Whitewood (spruce) or Redwood (Pine), most garden buildings sold in the UK are made from such wood.

The Wood Protection Association says that “the risk of attack increases significantly if the moisture content of wood, for any reason, rises above 20%” they also talk about how more lower durability cuts of wood (known as sapwood) are getting used to build with than in years gone by. They also say that “sapwood on the other hand is a source of food for many species of fungi and insects and is always vulnerable to attack.” This risk is particularly prevalent with European softwoods.

The BS 8417 code of practice (this advises on the choice of timber species and the use and application of wood preservatives) and BS EN 350:2016 (this advises on methods for determining and classifying the durability of wood and wood-based materials against biological wood-destroying agents) says the natural durability class of such European softwoods is between 3 and 5. With class 3 listed as moderately durable, class 4 listed as slightly durable and class 5 listed as not durable. All three classes have a service life of less than 15 years in a frequently wet environment (such as a UK garden). Yet the application of a preservative treatment or modification of lower durability species is designed according to BS8605 part1 (this is the British standards specifications for external timber cladding) to extend service life to 15/30 years or more.

Having a wooden garden structure supplied as untreated is relatively rare. The vast majority of wooden buildings are supplied with some form of basic treatment, usually a short term water based dip treatment. If you buy an untreated wooden building/structure then we strongly advise that you treat it annually with a solvent-based wood treatment. For full penetration it requires 2-3 coats. It is also recommended that you treat the inside of the structure as well.

If you are wanting something that will require much less maintenance throughout the products life cycle then we would strongly suggest looking at something that is pressure treated also known as tanalised timber.

By correctly treating timber you can take a sub 15 year service life for a not very durable European softwood and extend its service life to 15/30 years or more according to the Timber Decking and Cladding Association. ↩

2. Cladding types identified: interlocking boards, interlocking log, tongue & groove ↩

3. Global cladding data sourced from: All interlocking log log cabins ↩

4. Top cladding data sourced from: Top 89 interlocking log log cabins ↩

5. 14’x12′ cladding data sourced from: 111 14’x12′ interlocking log log cabins ↩

6. Cladding thickness types identified: 19mm, 28mm, 34mm, 40mm, 44mm, 45mm ↩

7. Global cladding thickness data sourced from: All 44mm log cabins ↩

8. Top cladding thickness data sourced from: Top 89 44mm log cabins ↩

9. 14’x12′ cladding thickness data sourced from: 49 14’x12′ 44mm log cabins ↩

10. Roof material types identified: tongue & groove ↩

11. Roof thickness types identified: 12mm, 16mm, 18mm, 19mm ↩

12. Roof covering types identified: epdm synthetic rubber, heavy duty mineral felt, mineral felt, polyester felt ↩

13. Floor material types identified: tongue & groove ↩

14. Floor thickness types identified: 12mm, 16mm, 18mm, 19mm, 28mm ↩

15. Glazing material types identified: double glazed, horticultural glass, single glazed, styrene, toughened glass, toughened safety glass ↩

16. Glazing thickness types identified: 3mm, 4mm, 34mm ↩