I have plaster coming off a interior wall in my home its is a plaster wall covering brick. I need to know how to fix were the plaster has come off the brick

 

Is this exterior brick? Does it get wet?

 

it does not get wet its in my main hall way

 

Can you post a picture? Depth, width and height of this loose plaster?

 

So that's a chimney... and my question still stands. Just a heads up: your chimney may be leaking, if there's no other explanation for the plaster peeling off.

How much plaster is missing? Is the surrounding plaster solid?

 

You probably have efflorescence going on, due to moisture leaching the salts out of the brick, due to moisture from inside the chimney, if you are sure there is no leak but chances are you cannot be certain.

Either way - scape off what you can, and get as much of the crumbly off with wire brush (wire brush on drill even), vacuum, then paint with paint that can be painted over powdery paint. Then once dry, then use something like Durobond setting-type mud to skim with.

 

If this hole is small like less than a foot square and the plaster is less than a half inch thick then the advice above is fine. I would add clean the efloresesence if of that is going on then wash it with a 50/50 vinegar/waer solution and rinse with clean water then use a bonding agent and the durabond. If it's larger than about a foot square you will get a better patch for probably less money if you If the patch is thicker plaster will let you do it faster. Do it with plaster like StructoLite or Gypsolite then finish with the Durabond or EasySand of the like.

This is not the way I would do it but it is pretty amateur friendly way.