What is Tongue & Groove Cladding?

Tongue and groove cladding is an interlocking timber board which is used to cover a frame of a building.

There are cladding options throughout the shed and summerhouse industry.

These are the most common cladding types that you have probably heard of while searching for your new garden building -

• Overlap
• Tongue & Groove (T&G or TGV)

But what do they mean, and what cladding type should you choose - Overlap or tongue and groove?

What is Overlap Cladding?

Overlap is usually a rough sawn timber board that is attached to the frame of the building by overlapping each board to prevent rainwater entering the walls of your shed.

This is not a tight fit  which means that the chance of water ingress through the walls is much higher than a tongue and groove board.

Also, as this is a rough sawn timber, which is more porous, it has a higher probability of water soaking into the timber.  

Overlap is considered a budget option and is not the best option of wall cladding for a shed or summerhouse. 

Tongue & Groove Cladding

Tongue & groove boards are smooth planed, making them more resistant to water soaking into the timber plus they are designed to interlock. The boards slot together – “tongue” on one end to the “groove” on the other - kind of like a jigsaw piece! This makes a tight fitting and much more effective at keeping water out of your building.

Tongue & Groove boards come in different sizes and shapes. You are likely to come across shiplap or loglap as a wall cladding option.

Each profile gives a different overall look but if the thickness is the same in both loglap & shiplap then the cost should be the same, if not very similar.

Timber Thickness

While you are choosing the right timber cladding type for your garden building, we highly recommend considering the thickness of the cladding too.

Any reputable garden building company will advertise the thickness of timber. The thicker the board the stronger it is, the more resistant to warping & shrinkage it will be plus it will be a better natural insulator.

Of course the thicker the timber, the more expensive it is, but if you consider the lifespan of a 20mm thick board alongside a 12mm thick board, the 20mm is going to last longer and therefore considerably reduce the chance of needing replacement - in the long run, it’s a good investment to make!