Plaster repair for blown plaster

ashe

We're about to start a program of decoration and improvements in our home. The decorating is already to a decent standard so we aren't in any particular rush, but there are a few hairline cracks in a few rooms and knocking on the plaster there gives a hollow sound, which I believe indicates blown plaster.

Before I get several plasterers round for a quote, can anyone tell me the best approach for blown plaster? do they need to strip the whole room back and redo it, or can they just cut that part back and redo it?

We're having some AV work done anyway in the living room so cables will be chased into walls etc so there will be plenty of work to do in the room in general, just need a bit of clarity around what the "correct" way to do all this is so I know what to ask for / ensure that the job is quoted for correctly

FreeBear

The problem with blown plaster is invariably, when you chip off the blown section, a whole load more comes away. What I have done with some patches is drill a few small holes (around 6mm dia.) through the plaster and then inject an acrylic solution. Seems to have worked quite well, and the small holes were easy enough to fill afterwards.

cybervic

Assuming there are many blown area and it's been a long time since last plastering, the best for longitivity is to strip it all back to brick wall, use bonding or hardball as a base coat (or plasterboard), then finish it with skim coat. This gave the best finish, less change of crack line in future, but can be an expansive job.

A more cost effective way is to chip off blown areas (knock on the wall gently and you should be able to hear a more hollow sound if it's blown), repair it one by one and re-skim either whole wall or just the blown area. However, because skim coat dries on different surface (the old and newly repaired area), You might see some sort of crack on the edge of those repair areas in future.

They are all correct ways, you have to choose what's most for you. I am in the process of renovation and opt to repair most walls instead of replaster completely because I know I will move on in few years time.

Norman_Castle

FreeBear wrote: »

What I have done with some patches is drill a few small holes (around 6mm dia.) through the plaster and then inject an acrylic solution. Seems to have worked quite well, and the small holes were easy enough to fill afterwards.

What did you inject behind the plaster?