Plastering over plaster may sometimes be a very necessary task in order to ensure a healthy environment in your room. But you may be wondering whether you can plaster over plaster. Will it be sensible?
This article will help you figure out just that. We will discuss whether you can plaster over plaster directly. Whether you should remove the old plaster before putting a new plaster on. And finally, we will walk you through how you can plaster over a plaster. So read ahead to learn more about the process.
Can you plaster over plaster?
You can plaster over a plaster for sure. But it is not recommended by experts. Note that plastering needs a very tacky and adhesive surface underneath the plaster in order to ensure a great bond. But an existing plastered wall is dry, thus, will not be able to provide such a surface.
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You can definitely plaster over plaster. But experts advise against it. You should clean your wall first and then proceed to plaster it.
You should not plaster over plaster, especially if it is dry or blown. This does not solve the problem, rather makes it worse. Let’s take a look at different kinds of existing plaster and whether it would be appropriate to plaster over them:
Plaster over lime plaster:
you can plaster over lime plaster. But you will have to be quite technical in the process. You can plaster lightly with some multi-finish plaster over the lime plaster. But you will have to watch out for any dampness or mold in the room.
Plaster over cracked plaster:
If the plaster is old and damaged, it may sustain cracks. But you cannot plaster over cracked plaster. In this case, you will need to fix the holes and cracks on the wall first.
You may use sealant or caulk on the cracks in order to fill them. Then you can plaster over the existing plaster.
Plaster over lath and plaster:
you can plaster over lath and plaster. But you will have to be very careful about the specifics of the issue. You can install a drywall panel over the existing lath and plaster layer. This will make a much better surface for the plaster.
Plaster over blown plaster:
You should not plaster over blown plaster. Plastering over a blown plaster does not solve the problem. In fact, the weight of the new layer of plaster is likely to make matters even worse.
So you should remove the blown areas first. Then you should fill those areas and layer plaster over that.
Plaster over dry plaster:
You should not plaster over dry plaster. The plaster needs an adhesive layer. And a dry plaster will not be able to serve it.
Can you put new plaster over old plaster?
You may feel the need to put on a new layer of plaster in your home or office. But this entails a lot of work. To make matters easier, people often wonder whether they can plaster over the existing plaster.
The simple answer to this query is that you can definitely plaster over plaster. But there are several factors that you will need to keep in mind.
Note that when you are plastering a wall, it will require an adhesive surface underneath. On the other hand, an already plastered wall appears to be super dry, which does not make a very welcoming surface for the plaster.
You should not plaster over a wall that is blown or has sustained cracks. It will not solve the issue, but rather worsen the problem with the weight of the plaster. You will first need to fix the plaster underneath. Once you have addressed all the cracks and holes on the plaster, you can plaster over the existing one.
Do you have to remove old plaster before plastering?
While you can plaster over plaster, it is not recommended. Since plastering needs a smooth, adhesive surface, a dry, existing plaster cannot ensure that. However, removing the entire plaster altogether seems like a very hard job as well.
So you do not have to remove old plaster before plastering, but you should fix the cracks, holes, or blown areas in the plaster. You should definitely fix the cracks and holes on the existing plaster before you put in a new one. Once you have fixed the existing plaster, you are all set for putting a new plaster on the wall.
2 reasons why you can plaster over plaster
You can definitely plaster over plaster under certain conditions. Let’s take a look at the reasons why you can plaster over plaster.
Removing the old plaster is time-consuming:
You can plaster over plaster because its alternative is quite time-consuming. If you want to remove the older plaster, you will have to remove the entire layer from the whole house. Then you will have to start from scratch.
While this process sounds very intriguing, you would have full freedom in your project and would have to deal with much fewer issues, it is very time-consuming. If you follow the long road, the entire project will take you months to finish.
Appropriate wiring and insulation:
If the wiring and insulation in your home are alright, then you can plaster over plaster. This would be the right condition to proceed with your plastering process.
On the other hand, if your home still has an outdated wiring system that does not adhere to the local building code, you should not plaster over plaster. In that case, you should tear down the old plaster, fix the wiring system and insulation in your house, and then proceed with the plastering system.
When can you plaster over plaster?
Let’s take a look at the conditions in which you can plaster over plaster. Read ahead to learn when you can plaster over plaster.
No cracks and holes in the plaster:
You can plaster over plaster when there are no holes or cracks on the wall. Otherwise, the new layer of plaster will not sit right. It will not even be durable if you put a new plaster over a plaster that has cracks on it.
Your old plaster may have sustained some cracks and holes, it is very natural. You should not plaster over plaster that has cracks and holes in it. In such a case, you will need to fix the cracks and holes in the existing plaster, preferably with some good quality sealant. Then you can proceed to plaster over plaster.
The plaster is not blown:
If the existing plaster is not blown in any spots, that is when you can plaster over plaster. If the plaster is blown, you should first fix those spots, then proceed to plaster the wall.
If you do not fix the blown area, the matter will get worse after plastering. The additional weight of the new plaster, which is at least 1 inch thick, will make the blown spots worse. In that case, the chances of the new plaster coming off increases.
How to plaster over plaster?
Let’s take a look at how you can plaster over plaster. Read ahead for a step-by-step guide.
Fix any cracks or holes in the plaster:
If you find any cracks or holes in the existing plaster, you should fix them before proceeding. Make sure to apply a strong sealant to the cracks and holes in order to ensure a smooth process.
Apply a base coat:
Now that you have covered all the cracks and holes in the wall, it is time to apply a base coat over the plaster. This base coat will ensure that the new layer of plaster is sticking well. The ideal base coat would be PVA emulsion.
You will notice a slight tint after you have applied the base coat. This tint will help you identify whether you have missed a spot.
Then you should apply a second coat of base coat.
Apply a layer of plaster:
Now you should apply a layer of plaster. The PVA layer will offer the adhesive and tacky layer that the plaster needs. Now you can apply a thin layer of plaster to the wall.
Wait for about ten minutes to allow the layer to sit firmly. Then use the trowel to finish the edges properly and flatten the surface.
Once the first coat has dried down, you should inspect and decide whether you need a second layer. If so, simply repeat the process. But apply a very thin layer the second time around.
Final Thoughts
You can plaster over plaster. But there are several factors that you should keep in mind. Cover all the cracks, holes, and blown areas on the existing plaster before you apply a new layer. If you need new wiring, tear down the existing plaster, fix the issues, then apply plaster newly.