Muppet proof plastering advice

[vipper]

I've got a few areas that require something more than an assault with a polyfilla type product - areas about a foot square that are back to the brick where the plaster has blown or is crumbling / missing from previous decorations.

Any pointers for someone who struggles to know his derriere from his plastering trowel? Paying somebody who knows what they are doing is not currently an option.

 

[MarkBarl]

You're off to rocky start, as plasterers use a float. I've tried and failed to patch up plaster work and would always try to find someone else to do it for me. Ask your mates if anyone is any good. If not, from what I do know. Don't use an all in one product, as the finish will not be as good. Damp the wall before applying as this will help the plaster key to the wall. When applying finish coat, damp where it joins the other plaster to try to stop the new plaster shrinking and cracking. Use a mist spray or brush to damp. Don't try to put too much on at one time. If this is your first attempt, take your time, keep calm and be prepared to make a mess.

 

[roughcaster]

Mark,
Vipper WAS right.Plasterers when plastering, mostly use a plastering trowel, and on occassions a float, be it plastic or wood. A steel plastering trowel is not called a float by the trade,it's a trowel.

Roughcaster.

 

[MarkBarl]

That's me put right. Hope the other advice was sound though.

 

[Richard C]

It’s a little more involved than that but even a complete novice should be able to achieve a reasonable finish on an area of a one square foot or so!

Remove all the loose plaster, PVA the wall (1:5) & leave to dry overnight. PVA the wall a second time (1:3) immediately before applying Bonding plaster as a base coat. Leave it about 3mm below the surrounding wall & don’t apply more than 8mm thick in one hit or it will crack, build it up in layers if necessary. If it starts to crack I use a spray to slow down absorption but don’t overdo it. Once that’s gone off, PVA the new plaster & surrounding wall area again & fill with Multifinish, slightly proud of the surrounding wall; while it’s still wet, pull a straight edge over the area to get it smooth but don’t make it hollow again. The next bit will be the tricky bit for you as you need to get the timing right; once it starts go off, trowel the plaster vertically & horizontally, blending in with the surrounding wall but at this stage the edge will still be very rough. Leave until it’s almost set & finally polish all around the edge into the surrounding wall; you will need to work it quiet hard to get a smooth transition & you can use a little water to hep but not too much; if the join can still be seen, you can always sand it smooth & fill any small imperfections afterwards.

 

[roughcaster]

Hi MarkB,
There was no need for the red face.Good on you for giving of your time, and having the interest to try to help somebody else solve a problem on this Forum.This is what it's all about. We all learn every day from other peoples comments and experiences.

Roughcaster.