Plastering issue

[Scoottyyy2003]

Found some cracks and loose areas in the plaster of some of my walls.
Gone through the process of removing what's loose and getting things ready to patch up.
Some of the cement mix below the plaster is also loose and I'm wondering if I'm better off just patching it up or removing the entire wall back to brick and starting it all over.

 

[darrington]

Quite often, once you start removing loose areas here and there, it loosens other areas too, I've seen that many times. You could patch it up, but then again, if it's bad, is it worth it?
A good way nowadays if it's pretty bad, and more or less ruined all over, is to remove all the plaster, take it all back to brick, then either get the wall re-plastered back onto the brick, or, batten the wall with 2"x1" battens or similar, then insulate in between the studs with some sheets of 25mm thick, celotex insulation boards, then plasterboard the whole wall with 12.5mm plasterboard. You can then either TAPE the wall into the existing internal wall corners and ceiling, or you can tape and skim it. The thickness of the battens you use is up to you.

 

[bobasd]

i dont understand what the cement mix below the plaster is? has the wall been rendered and skimmed or do you mean motar joints in masonry?

 

[cwhaley]

i dont understand what the cement mix below the plaster is? has the wall been rendered and skimmed or do you mean motar joints in masonry?

Surely the render which goes onto the bricks, before being coated with multifinish?

 

[darrington]

The cement coat, "as you call it", is "the float coat". Most, if not all solid, plastered wall are "float and set", float coat being the thick undercoat, "set", being the finishing coat or skim coat. Years ago, most "float coats" would have been cement or lime based. You can still get this nowadays too, but now, you also have Gypsum based undercoat plasters, Browning, Bonding etc.

 

[bobasd]

the OP doesnt call it a cement coat.

its not sure that its render, thats why i asked. whatever it is you dont coat finish plaster on to anything you skim it on. coating is usly used for painting.

 

[darrington]

Float and set plaster=
Scratch coat/float coat onto the bricks, blocks etc. Could be sand, cement and lime, could be Gypsums
Finishing coats of plaster,, onto the float coats when set.
When I started plastering in 1964, we used a floating trowel to put on the "float coats", then we would use a setting trowel and a setting float to put on the "3" setting coats, (trowel, yellow pine setting float, trowel), "3 coats of finishing" it's always been called "coats of plaster". We even used a "cross grain float". Ther's a lot more to plastering than skimming.
Same as roughcasting, a scratch coat, top coat, then cast on the chips.

 

[roughcaster]

Of course plaster is put on in coats.

 

[bobasd]

your both right i was well wrong on that. why i said that ive no idea.maybe i should start re-readin what i write.

 

[darrington]

You're alright Bob,, no worries. Keep posting pal.