By Amy Hanlon
The wonderful world of timber buildings can be a confusing one, and the question of 3-tier wall vs lining and insulation is a perfect example of a seemingly simple choice that needs some background knowledge before you take the plunge.
At Gillies & Mackay we build 3-Tier Sheds and 3-Tier Garages. We also build Blackstone Garden Rooms. But here’s the thing: these building types are more closely related than you might think. Let’s take a look.
Gillies & Mackay’s 3-Tier Specification
This diagram shows how our 3-Tier Sheds and Garages are constructed. There’s an outer layer of pressure-treated cladding, an air cavity and breather membrane, then there’s an inner layer of OSB. These materials are fixed to C24-graded framing and topped off with steel box profile roofing.
3-Tier Sheds and Garages are robust buildings that will not leak or allow water inside. They’re perfect if you’re storing something precious like a classic car or expensive tools or hobby equipment. Anything that needs a stable, dry environment is perfectly housed in a 3-Tier Shed or Garage.
Gillies & Mackay’s Blackstone Garden Room Specification
If you’re a sharp-eyed sort you’ll have spotted some similarities between these two diagrams. A Blackstone Garden Room also has an outer layer of pressure-treated cladding, an air cavity and breather membrane, and an inner layer of OSB. This same water-tight construction forms the walls and roof of every Blackstone Garden Room we build.
The difference between the 3-Tier specification and the Blackstone specification is in the insulation and lining.
A Blackstone Garden Room is an insulated and lined 3-Tier building. Specifically, we add 100mm of Knauff insulation compressed to 95mm. A vapour barrier is installed over this, and finally, a lining material finishes the interior of the building. Some customers choose V’d timber lining, some choose plasterboard which can be painted or papered, and some combine both finishes.
Insulation and lining help the building stay warm when it’s cold outside and cool when it’s warm outside. They add an extra layer of protection from the elements.
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What’s the difference between a garden room and a garage?
One main difference between a garden room and a garage is the function of the building.
Garden Rooms are versatile spaces that form perfect offices, sitting rooms, business premises, hobby rooms, art studios, workshops and everything in between. Our Blackstone Garden Rooms are fully compliant with Building Control standards, meaning that they meet the safety and structural requirements for living accommodation. Whether you’re building an Airbnb or a sunny getaway in your garden, these buildings will fit the bill.
Garages, on the other hand, tend to be used for storage and as workshop spaces. In general, a Blackstone Garden Room will be occupied for more time than a Garage.
When should I insulate and line my 3-Tier Garage?
But hang on…you might want a Garage to form a watertight workshop where you’ll spend hours honing your craft. Your Garage might be for business premises or combine storage and other usage. There are plenty of cases where a Garage will be occupied just as much as a Garden Room. If this applies to you, lining and insulation could increase your comfort while inside the building and save you money on heating costs.
But if you’re a welder or a glassblower, and your time is spent trying to cool your building down, this may not be a priority for you.
Your choice comes down to your intentions for the building. If you know that you’re going to be in a 3-Tier building for long, cold hours, adding insulation and lining will create a more comfortable building that’s more economical to heat.
Will insulating a Garage prevent condensation?
Condensation might be another consideration. If you’re regularly storing wet items inside your building, the water on these items can condense on your interior walls. Since the interior wall of a 3-Tier building is made of OSB, over time this layer will soak up water and encourage mould or even rot.
To prevent wet items from damaging your Garage you can paint the interior walls with a protective paint like Sadolin, or you can protect the walls further by adding insulation and lining.
To be clear: storing wet items in an enclosed building will lead to condensation, whatever the walls are made of. But if your building is for this specific purpose, adding insulating and lining the walls and roof with a more suitable material will protect it from damage.
The best practice for storing wet items is to dry them off before storage. Not only does this prevent these items from damage, but it also prevents excess water in your building, protecting it from condensation, water damage and rot.
How much does insulation and lining cost?
The cost of this job will depend on various factors. Sometimes customers choose to tackle this job themselves, and sometimes we do it as part of the installation of the building.
Costs will depend on the materials used and the size of the building. Using V’d redwood costs considerably more than using plywood, and the thickness and type of insulation material will also impact the cost.
However, here is a Gillies & Mackay Garage whose owners opted to have insulation installed. This building is insulated with 100mm Knauff insulation and lined with 9mm plywood.
Here’s a breakdown of the cost of the project:
| Building & Garage Door | £11,829 |
| Insulation & Lining | £4,293 |
| Windows | £650 |
| Guttering | £620 |
| Total | £17,392 |
3-Tier Wall vs Lining & Insulation: which is right for me?
Whether you opt for a 3-Tier building or choose to add lining and insulation, you’ll get a building that’s completely watertight and built to last a lifetime.
If comfort and heating bills are your main concern, lining and insulation will address both of these issues. But if you’re primarily looking for a secure storage space, insulation and lining may not be your priority.
The best way to compare these building types is to come and see them in real life. Our Show Area has two timber Garages, a 3-Tier Shed and two Blackstone Garden Rooms that you can visit to help you decide what’s right for you. Come and see us Monday to Saturday and have a good look around.
