That’s pretty much what garden room insulation is all about. It’s that simple. The only technicalities are the type and thickness of the insulation material. There is also the matter of ventilation.
These are all subjects that we will cover in this article. So, keep reading if you want to know more about insulating a garden room.
Here are the best three materials for insulating a garden room.
With a thermal conductivity value of 0.022 W/mK, PIR is the most effective insulation material on this list. It has twice the performance of the remaining two. PIR boards are also self-supporting. So, you won’t need support battens to hold them in place. Finally, they are durable, damp-proof and moisture-resistant. PIR is the most popular material for insulating garden rooms.
There are two types: rock wool and glass mineral wool. The former is made with wastes recycled from blast furnaces, while the latter is made with recycled sand, limestone and glass. Both types of rock wool have a thermal conductivity value of 0.037 W/mK.
This means their insulation performance is half that of PIR. However, they are more affordable and better at soundproofing. Mineral wool insulation is also not self-supporting. So, you will need support battens. However, this soft, non-self-supporting nature makes them flexible and perfect for sealing gaps and crevices.
Cavity slab insulation is similar to mineral wool insulation. They are both non-self-supporting insulation materials with good soundproofing qualities. They also both have a thermal conductivity value of 0.037 W/mK. So, expect similar performance when using either for insulating a garden room.
It’s all about insulation performance. PIR has twice the insulation performance of both mineral wool and cavity slab. Therefore, 50mm PIR boards give the same performance as 100mm thick mineral wool or cavity slabs.
You should also consider how the insulation material’s thickness affects the space inside the garden room. Insulation takes up around 50-150mm of space. This may seem small, but it’s still enough to affect doors and windows.
Here is what you need to know when insulating a garden room.
Walls make up 35% of total heat loss. Insulate with 50mm PIR boards, 100mm cavity slabs or 100mm mineral wool.
Roofs make up 25% of total heat loss. Insulate 75mm PIR boards.
Floor makes up 15% of total heat loss. Insulate with 75mm or 100mm PIR boards.
Windows and doors comprise 10% and 15% of total heat loss. Change this by upgrading the windows and doors to double glazing.
The process will vary slightly depending on the insulation material and the part (roof, wall or floor) you are insulating. Therefore, we have divided this section into four segments.
The first segment is a step-by-step guide for insulating a garden room with PIR boards. The second will cover how to do it with mineral wool and cavity slabs. The last two segments provide notes for insulating garden room roofs and floors, respectively.
There are two categories of roof insulation, namely warm roofs and cold roofs. In warm roofs, the insulation material is above the rafters. In cold roofs, the insulation material is under the rafters. Warm roofs have better ventilation performance but can cause problems with permitted development rules.
With floor insulation, the insulation material can also sit under or above the floor of the garden room. The 50-150mm space each layer of insulation takes may seem small, but it could still affect the opening and closing of doors and windows. Therefore, putting the insulation material under the floor is better, although this is not always possible.
Pre-insulated garden rooms are relatively expensive. But, as you can see, it’s not difficult to insulate a garden room yourself. Another option is to hire a professional. Either way, insulating your garden room is the only thing that matters.
Insulating a garden room makes it thermally efficient. It lets you maintain desired room temperature year-round at minimal costs. It reduces the cost of keeping your garden room warm in cold months and cool in warm months.
However, insulation does come at the cost of ventilation. By making the room airtight, you impair airflow. Moist air can’t escape, and fresh air can’t enter. This then creates condensation and dampness issues. Solve this by installing trickle vents.
PIR is the best material for insulating garden rooms. Mineral wool and cavity slabs are great options, too. Other alternatives include sheep wool, hemp, reflective foil and recycled plastic bottle insulation.
Yes, insulation affects ventilation, but you can fix this with trickle vents.