Sealing walls with PVA is a very much misunderstood operation. DIY Doctor gets many emails saying that PVA should not be used on walls before they are tiled. This is simply not true. The fact is that they do not understand the process of using PVA properly. PVA can be used to seal any type of porous surface,including plasterboard and if it is done properly it will give you a much much better job than working on unsealed walls. To seal a wall the PVA should be dilted at about 20 – 25% PVA to 80 – 75% water. This type of dilution allows the PVA to soak into the material with the water sealing not just the immediate surface but a little bit deeper into the material. Not only does this form a proper seal but it makes the top layer of the material stronger by binding it fully with the depth of wall immediately below the surface. To those who tell us they have been tiling for 40 years and they KNOW that PVA should never be used, we say that you may well have been tiling for 40 years but you have never taken the 5 minutes or so that it takes to understand how PVA works!
Post time: Jun-24-2017