Insulated plasterboard is a fantastic product. It enables you to add insulation to a property with ease and convenience. The insulation is attached to the back of the plasterboard, meaning it can easily be installed inside a property. This gives the same benefits as something like cavity insulation.
Fixing insulated plaster to a solid surface, such as brick, is relatively simple, and you have two main options:
- Dot and dab with additional secondary fixings
- Attaching timber battens to the brick wall and screwing boards to the timber.
Both of these will give a similar finish. For example, 2×1 inch timber battens, will give a similar depth to dabs of dry wall adhesive .
The method you choose is up to you. There is no right or wrong answer, it is mainly down to personal preference. However, there are some instances where one option may be better than the other.
Both processes are relatively simple, although the drywall adhesive may be slightly quicker than timber battens. With that said, this will depend on the surface, as well as your own personal skill set.
For example, if you are working on a completely flat, plum surface, you may be able to install battens quickly.
Alternatively, if the surface is uneven and slightly out of plum, applying dabs to even out the surface would be much easier than timber battens. The battens will need packing to provide a straight and plumb surface to fix too.
Below you can learn in more detail how each process is done.
Fixing insulated plasterboard with dabs and secondary fixings
If you decide to install your boards with a dot and dab adhesive, there is a specific process you will need to follow.
- Firstly, you will need to confirm that the surface is free from defects, dust, lose materials and excess moisture. Most of these will be easy to achieve, by cleaning the surface and possibly making minor repairs.
If moisture is present you will need to identify where it is coming from and resolve the issue. Following this the wall should be dried and it will be ready for the next step. - Next you should cut your boards floor to ceiling. If this can be achieved in one board, you should aim to have a 15mm gap at the bottom, lifting it away from the floor.
- Once walls are clean and dry, and your boards are cut, you can apply adhesive. The first place this should be applied is around the edges of the room, as one solid continuous line of adhesive. This should also, go around the edges of any openings, such as windows and doors.
Then inside this perimeter you should also add dabs every 12-15 inches. - Next you can apply a bonding agent to the back of the board to aid with adhesion. Then you can stick you boards in place. Here you will need to use a spirit level to ensure the final surface is plum and straight.
- All boards should be finished with 6 mechanical fixings that are applied through the dabs. These will offer additional support. They are also designed to stop the boards falling away from the wall in case of a fire.
If the fixings were not present, the insulation would burn off first during a fire. This would cause boards to drop off the wall, creating an obstacle for anyone trying the leave or enter the property.
You can see a simple video below showing the process by Kingspan. They are a company that manufacture this type of board.
Fixing insulated plasterboard with timber battens
As a joiner, this is my preferred method. Its the way I have installed these boards every time I fitted them.
The process is quite simple and in the past, I have used 2x1inch pressure treated timber battens . In fact, my favourite timber for this is roofing lat.
Your timber will be fixed to the wall with plugs and screws. Kingspan recommends adding a strip of DPM behind each timber. I tend to prefer plastic packers, which I use to fix the timber plumb to the wall. This tends to separate the timber from the brickwork which will avoid any moisture transfer.
I only use plastic DPM in areas where timber is touching the brickwork. With that said if the wall was completely flat, straight, and plumb, I would probably use DPM strips as recommended.
Timber is fixed around the edges of the room (floor, ceiling, corners) and then uprights are added at 400mm centres. This gives 4 rows of fixings per board. The boards should be fixed with drywall screws.
For me this process seems much simpler, but I am a joiner so I may be bias.
Kingspan also provide a short video on how they recommend you do this (see below). The only real difference is they recommend a max of 600mm centres and using the DPM strips we mentioned. Otherwise, its exactly the same way I would to it.
Conclusion
If you need a simple method to add insulation internally, you can’t go wrong with insulated plasterboard. Whether you dot dab insulated plasterboard, or use timber battens, installation is relatively easy.
Obviously, this is not the best option for timber stud walls. With a stud wall you can install standard insulation inside, for a much lower cost.
Insulation boards are quite expensive, but you are paying for convenience. Kingspan is certainly the most well-known brand. However, there are competitors that offer similar products. So as with anything, you can shop around to find the best price.
