Tongue & Groove

At North Sheds all of our buildings are fully tongue and grooved (T&G). Each piece of timber has a slot (the groove) cut all along the edge, and a thin, deep ridge (the tongue) on the opposite edge. This enables the timber to slot closely together, offering added protection to wear and tear as well as water prevention. T&G construction gives our buildings excellent stability even in the harshest weather conditions.


All external cladding is ex 16mm (dressed down to aprox. 12mm), 4ths grade Spruce. All framing is pressure treated 45mm x 35 mm Spruce. Flooring is ex 19mm (dressed to 16mm Redwood and our roofs are ex 16mm Spruce .We use black Mineral Flexi Glass roofing felt which has a 10 x 1 metre roll weight of 28KG. This felt will not warp and is fixed using clout nails on the overlaps only and a Bitumen based sealant is used to stick the felt to the roofing boards reducing the likelihood of nails causing leaks.


We use ring shank rust proof nails to construct our buildings reducing the movement of the cladding and damage from corrosion.


Windows can be positioned where you would like them at no extra charge. The windows come standard as fixed, however you can opt to have them opening for a small fee.


Our treatment is Included in the price we will treat your building with a preservative. In our factory called Protec. This is water based wood preservative and will colour your building Golden Brown inside and outside. We have a large dipping tank where the panels are fully submerged into the treatment. This treatment will protect the building from weather damage for around 1 year then it is recommended that another coat of treatment is applied. Assembly is also included within our prices and this means your building is guaranteed for 12 months against materials and workmanship. We have a highly experienced Team to do this. If you would like to find out more about our team please visit the ‘About Us’ section.

Properties of the timber we use:


Spruce is a white-wood, it doesn’t discolour anywhere near as much as pine (Redwood) so it is more aesthetically pleasing inside a log cabin, shed or summer house. It is more dense than pine as well, the knots are tighter and usually there are less of them than in pine. It is structurally stronger but is more expensive than pine.

Pine Redwood


Pine is known as a redwood, it’s widely used for a lot of things we use daily. No doubt you will have some pine furniture at home. Pine isn’t as dense as Spruce and therefore it does absorb water quicker. It’s the cheaper of the two types we can use in a log cabin. We use it very widely in the garden for fencing, posts, furniture, play equipment etc. Because it is less dense, we will pressure treat it to guard against rotting in the long term. It also tends to have looser knots and more of them, it changes colour with sun light to a darker colour. It’s also not as structurally strong as spruce and has wider ring growth.




Your building is made of timber, which is a natural product and is prone to knots, cracks, & slight shrinkage or expansion. All these properties are natural and not faults in the garden building.


Your garden building has been treated with Protec Shed Grade preservative, which will protect the building for many years, however the building will “sun bleach” and should be treated every year with a good quality coloured preservative. All hardware (hinges, locks etc) should be oiled at least once a year.

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