Dot and Dab Thickness

So you want to know how thick a dot and dab wall is? There are a few different reasons why you may be asking this so I will attack the answer from a few different angles, hopefully I cover everything you need!

How big is the gap between plasterboard and brick in a dot and dab wall?

The main reason for wanting to know this is if you are trying to run cables or need to hang a heavy object on a dot and dab wall. You might need to know how far you will need to drill before hitting brick, and therefore what length of fixing you will require.

I can tell you what the usual depth will be but the true answer will be, it depends. Not all builders create dot and dab walls exactly the same, and some might not even make them the same every day. Houses next door on a building site might end up with different gaps depending on how the drywaller was feeling that day. But this does not mean all hope is lost, we can give you a general idea of what it should be and also show you how to measure the depth.

The Standard practice is to make the adhesive dabs 10mm thick. Then you have the plasterboard sheets depth on top of this which on a standard board is another 12.5mm. So from the outside of the wall back to the brick will be roughly 22.5mm as standard. No drywaller is measuring out the depth of their dabs though, that would be a lot of wasted time, so this is just a guide.

The easiest way to find out the depth is simply to measure it. Make your hole in the plasterboard where you are going to place your fixing. You can then insert something long and thin like a screwdriver into the hole until it touches the wall. Hold the screwdriver right down where it meets the plasterboard, this will be your depth. Then pull the screwdriver out and measure to where you are holding it. You now know how far back it is to the brickwork.

If you don’t want to make a hole in the wall you can take a socket off and look behind there. Make sure the power is off at the fuse board before doing this!

How thick to dot and dab?

Now, this is more for the people creating a dot and dab wall. How thick should you make it? Well as I said above, standard practice would be 10mm thick adhesive with the plasterboard on top leading to a total thickness of around 22.5mm. however, there are reasons why you may need to change this. The main one being any plug sockets and light switches already on the wall.

You will obviously need to make your wall line up with these boxes so they sit flush with the wall. So simply measure how deep the backbox is and then match that with your adhesive thickness minute 12.5mm for the plasterboard sheet itself.

Maximum thickness of dot and dab

There is no set rule as to how thick you can dot and dab. But past a certain limit, it gets harder to do as you need huge blobs of adhesive. I would recommend only going up to around 40mm total including the plasterboard. This is no set rule though and if you feel comfortable going over it then go for it.

If you need to get your wall further away from the wall than this, then consider batoning it instead of dot and dab.