You have several ways to fix plasterboard to a brick wall. The main methods include:
- Dot and dab
- Dot and dab with secondary fixings – More common with insulated boards and if boards come loose
- Attaching to timber battens
- Plasterboard adhesive foam (less common)
Plaster board should never be screwed directly to a brick wall. There should always be a cavity between the wall and the back of the plasterboard. This small cavity is created by either an adhesive or a timber frame attached to the wall.
There are several problems with fixing directly to a brick wall.
Firstly there is a chance (especially in older walls) that the surface is not completely straight and plumb. This will mean you’re finished plasterboards have an uneven surface, and in certain areas, the screws could pull straight through the boards.
The advantage with battens, or an adhesive, is they enable you to create a straight and plumb surface.
The second issue, is the potential for damp. Plasterboard is extremely absorbent. When it comes in contact with any type of moisture, it will be soaked up. Therefore, if there is any moisture in the brickwork or mortar, for any reason, it will easily pass into the plasterboards.
Another issue is condensation. This can happen if the brick wall is particularly cold. If you screw plasterboard directly to the brickwork, the cold will transfer to the surface of the plasterboard. This will attract condensation (known as a dew point). Plasterboard is just gypsum covered in paper. Therefore, it will not take long for condensation to soak in and damage the material. It will also increase the risk of mould forming on the surface.
Are there any walls where you can screw plasterboard?
The only type of wall that you can screw plasterboard directly too, is a timber stud wall. Any type of masonry wall, such as brick, block, or stone will need to be fixed correctly with either timber battens or adhesive.
When fixing to a stud wall, drywall screws are used to attach the board directly to the studwork. This is best practice and will give an excellent fixing. Also it comes with none of the issues you would find trying to screw directly to a brick wall.
Most common way to fix plasterboard to a brick wall
The most common method for fixing plasterboard to a solid wall, is via dot and dab. To do this, you use a drywall adhesive. The adhesive is applied to the brickwork in dabs (hence the name). Following this, the board is pushed against the dabs and the surface is leveled using a straight edge and/or a spirit level.
This method has two obvious advantages over screwing directly to the wall.
- The board can be manipulated, by applying pressure to the dabs. This enables you to achieve a very flat surface, and a level can be used to ensure the wall is completely plum. If you are screwing directly, this is not an option, your board would run in line with the existing wall.
- The dabs create a small cavity (usually around 20mm). Due to this, you will drastically reduce the chance of damp, and hygroscopic salts passing from the wall. Any damp can cause serious damage to plasterboard, and the salts that come with it, can cause stains on the plaster, as well as attracting further moisture.
The gap will also reduce condensation. It will allow circulation behind the board. As well as reducing cold transfer from the brickwork, which could result in condensation on the face of the board. Water vapour in the air is naturally attracted to cold surfaces.
This is known as a dew point. It is the same thing that happens when water beads collect on a cold drinks glass. Essentially, warm moist air, is attracted to cold surfaces. When it hits a cold surface, it condenses back into water as the temperature cools. This is not good news for plasterboards.
Screwing plasterboard to a brick wall
Whilst you shouldn’t screw directly to a brick wall, that doesn’t mean you can’t use mechanical fixings. You can fix your plasterboard with screws. However, you will need to attach timber to the wall first.
Again, this offers several advantages. These are very similar to the advantages found with dot and dab. Firstly you are not screwing directly, which reduces the chance of the issues this can cause.
Secondly, just like dot and dab, you are able to create a flat and plum surface.
Attaching your plasterboards to battens is arguably a better-quality solution than dot and dab. However, it will cost more, as you do need to pay extra for the timber, and fixings.
It is also more time consuming and requires a certain level of skill. This is especially true if you are fixing battens to a very uneven surface.
Due to this, most people will opt for dot and dab, as it is relatively simple. It is also much easier to level a very uneven surface, as you simply apply pressure to manipulate the board.
If you are installing the plasterboard in your own home and you have the patience, I would personally use timber over dot and dab in most cases.
With that said, using a drywall adhesive is a perfectly reasonable method of fixing your plasterboards, and in some cases it can be your best option. As we mentioned previously, it is the most common method and it is relatively easy to achieve, for even the average DIY’er.
So as you can see, it is definitely not recommended that you screw plasterboard directly to a brick wall, or any other type of masonry. It can be done; however, it is not best practice and you run a very high risk of creating issues in the finished wall.
A much better way to do this, is to use either dot and dab, or a timber batten frame fixed to the wall. Both of these will give you a high-quality finish and ensure that your wall stands the test of time.