It is possible to dot and dab over existing plasterboard. Can You Dot and Dab Over Existing Plasterboard In comparison, skimming directly over old plaster would only add around 3mm.

One other consideration to make, is the space that you will save if you decide to just re-skimĭot and dab can add an extra 20 to 30mm to each surface in a room, which would mean a loss of space. This will provide an excellent finish and is suitable when used with a variety of backing surfaces. When you skim, your best option is to use a multi-finish plaster. Another option is using a product such as blue grit to provide a good key Once the second coat is tacky, you can apply your skim coat. If the surface is high suction, you may need to give it two coats.

Once the old plaster has been prepared, you can then coat it using a weak water and PVA solution. You should also make sure there is no loose plaster that could fall away with very little pressure. It’s very important to make sure that the old plaster is solid, and in good condition, with no blown patches. They will just require filling before you skim, or you could use scrim tape to cover them. Small hairline cracks are usually nothing to worry about. If so, you will need to sand and clean the surface to provide a better key for new plaster. It’s also possible that old plaster is painted. If it is in good condition, then you will just need to make sure the surface is clean. Yes, it is possible to skim on top of old plaster, but there are some things that you will need to consider.Īgain, the most important thing is the condition of the old plaster. What this shows, is you need to make sure the original surface is adequate and can hold the new boards. However, there is always a risk that your plasterboards won’t stay on for long if you don’t prep correctly. Just remember to make the surface as secure as possible by removing any loose plaster, then you can dot and dab over. This could easily result in the boards pulling the old plaster from the wall. If the old plaster is weakened, then your dot and dab will also be weak. When you dot and dab over old plaster, you should always remember that it will only be as secure as the substrate. Instead, you should completely remove all loose plaster before over boarding. Therefore, you should avoid dot and dabbing. This type of loose plaster will not hold the weight of new dot and dab boards. There could also be blown areas that have come away from the wall. Therefore, the weight of the new boards could be an issue and pull the old lathe and plaster away from the surfaceįor modern plaster, it may be showing signs of ageing such as cracking. Also, it won’t be as structurally strong as modern plasterboards. There is likely to be moisture in the old plaster, which can cause the dot and dab to soften and fail. If this is the case, then you will probably need to remove all the old plaster. If it is an old property, then it might have old lime-based plaster and lathes. This will ensure that the completed work looks right and will last. Is it Better to Remove Old Plaster Before Dot and Dab?Īs with all jobs, it is always better to ensure that you carry out the right prep work beforehand.

Old plaster wall