Applying a damp proof membrane to an internal wall is an excellent solution for damp issues in many situations. A membrane can be applied to a wall after a new damp proof course had been inserted or injected, and a DPM (Damp Proof Membrane) is an effective way of isolating damp walls and those that have salts and other contaminants. Your choice of damp proof membrane should be determined by the extent of the damp and contamination and the finish you require. DIY DPM kits are widely available and specific installation instructions will vary accordingly, and should always be followed closely. However, the general principles of how to apply a damp proof membrane are largely the same. So, here is a general damp proof membrane installation guide.
- A typical DIY Damp Proofing Kit will include a roll of meshed membrane:
It will also include plaster plugs and sealing washers, a masonry drill bit, and often a mastic sealant. This is to apply to the plugs before the membrane is fixed.
- Remove any loose, crumbling or flaking plaster from the substrate. The surface should be as clean and flat as possible.
- Using a knife or sharp scissors, cut the membrane sheet to size.
- Place the membrane to the wall and neatly fold around any corners. The crucial thing is that any wrinkles and creases are removed.
- Fix the membrane to the wall by drilling holes into the wall. It is best to start from the centre and works outwards, at 25cm intervals. Insert the fixing plug (and apply mastic, if using) and the sealing washer. Flatten out any creases before hammering each plug securely into place.
This video shows the process:
You can see a speeded up version of someone installing membrane to an entire room:
- Once all the plugs have been fixed to the wall, you are ready to apply your plasterboard finish to the wall. There are four main ways of doing this:
- Timber battens that are fixed horizontally
- Metal framework systems
- Direct plaster finish
- Dot and dab
Each of these methods work well. The dot and dab method is the simplest and quickest. Follow the advice and instructions given with the particular DIY Damp Proof Membrane Kit that you buy.
The video below shows each of these four methods in action.
Once the plasterboard is in place, you are ready to plaster and apply your decorated finish.
So, there you have it – your complete damp proof membrane installation guide. As we said above, there will be minor differences between the exact methods that you should use. However, these should be clearly explained in the kit you choose and in general the installation process is very similar, as detailed above.