render? plaster? insulated pb?

[mnemonix]

Hello everyone,

Last few days I've read everything I can on this forum about plastering & rendering and been practicing my technique with base coat & finish plastering on a practice wall. Before anyone says get a pro in, I lost my job when I bought this house and have no choice but to do-it-myself - I've already dug out and cast a new insulated concrete floor slab in the kitchen myself.

Anyway this is my kitchen wall, 9" solid brick, 100 years old:

It's previously suffered from damp and had an injected dpc by previous owners. It took me to actually sort the cause of the damp out though by replacing the floor and fixing a drain.

But what to do with these walls now? They've had every kind of finish applied to them at some point in their life - render, browning, hardwall, some kind of grey, lightweight stuff with big white lumps in it and who knows what else. I've removed everything that was loose, blown or crumbly, which was almost everything below 1.5m height and patched the worst of the brickwork.

- Do I need to render them with a waterproofer if they are now dry above the dpc? Or can I just use hardwall and multifinish?

- It's bitterly cold in here. How would insulated plasterboard fare in here given it is a kitchen? If suitable what should I put it over? Render, brickwork or plaster? Is dot and dab ok or battens?

Any help to choose the best option is appreciated bearing in mind I'm not a pro, just someone with the perseverence to keep at it until it's right, all be it with limited funds at the moment.

Sorry for the long post!

 

[stevethespreader]

now you have sorted the damp out i would float and set with sand and cement, you should also square your walls off by removing the odd shapes of plaster you have been left with to make floating easier espec the second pic, i wouldent use hardwall on a solid wall in a kitchen sand and cement is the way to go (also the cheapest), i can understand u thinking about boarding and insulating but if it was my house i would float and set

 

[mnemonix]

Thanks Steve.

So scratch coat with waterproofer then float coat without? Should I do these at about 6mm each so it finishes flush with the existing plaster, then skim the whole wall with multifinish?

 

[stevethespreader]

Thanks Steve.

So scratch coat with waterproofer then float coat without? Should I do these at about 6mm each so it finishes flush with the existing plaster, then skim the whole wall with multifinish?

if you feel safer adding waterproofer then add it in the scratchcoat im just about to render my own walls but im not using waterproofer but seeing as you have solid walls and have had damp probs then yes i would use it, put your scratchcoat on then when it comes to the foat coat rule your straight edge off the existing plaster, your old plaster will act as a screed to rule off

 

[stevethespreader]

Thanks Steve.

So scratch coat with waterproofer then float coat without? Should I do these at about 6mm each so it finishes flush with the existing plaster, then skim the whole wall with multifinish?

if you feel safer adding waterproofer then add it in the scratchcoat im just about to render my own walls but im not using waterproofer but seeing as you have solid walls and have had damp probs then yes i would use it, put your scratchcoat on then when it comes to the foat coat rule your straight edge off the existing plaster, your old plaster will act as a screed to rule off

forgot to say make sure you pva the edges of the old plaster before you render

 

[mnemonix]

forgot to say make sure you pva the edges of the old plaster before you render

Good call; but not the brickwork, that just needs damping down right?

 

[stevethespreader]

forgot to say make sure you pva the edges of the old plaster before you render

Good call; but not the brickwork, that just needs damping down right?

yes

 

[peaps]

With these walls you need to let them breath. Sand and cement is the wrong way to go. Don't use PVA either. Any of the mentioned above will cause you problems in the long run.


Lime is what is needed.

 

[stevethespreader]

mnemonix what was the origonal render? lime or cement?

 

[mnemonix]

The wall was a patchwork of everything you can imagine from repairs over the years. The most recent stuff at the bottom of the walls I reckon done at the same time as the dpc was very lightweight, grey with big white speckles in it. Above that, mainly soft browning with finishing plaster over it. Not much sand/cement at all but for an odd patch. I don't think there was any lime based render, but I wouldn't necessarily recognise it.

 

[mnemonix]

Just some of the many layers before I hacked it off:

It wasn't like this all over, but these areas had the most layers visible! Bottom right, very lightweight grey speckly stuff (came off in huge sheets). Centre of the hole left, soft red, crumbly stuff. Some sand/cement, skim, polyfilla etc visible too.

 

[stevethespreader]

Just some of the many layers before I hacked it off:

It wasn't like this all over, but these areas had the most layers visible! Bottom right, very lightweight grey speckly stuff (came off in huge sheets). Centre of the hole left, soft red, crumbly stuff. Some sand/cement, skim, polyfilla etc visible too.

blimey they chucked that on thick looks like bonding, it would have sucked all the moisture up in the kitchen like a sponge make sure all that is off, and also if the origonal render had cement in it go with a cement render, if the origonal specs of that house was sand and cement use sand and cement, theres no need to go changing things
"EDIT" the only thing that need changing is the layers of gypsum undercoat

 

[peaps]

it's 100 years old and done in LIME !!!

 

[peaps]

THe house was originally done in lime but yes over the years with other renders adding to the DAMP problems. These double solid brck walls need to breath it's very important to use a breathable plaster/render.

Personally I would dry line the lot if I was in your possition and if you are going to use a motar then I would hack the rest off. I don't see the point in leaving such small amount on the wall, renew the lot.

You would do well to dry line it.

 

[peaps]

It's not all gypsum, note he lives in Notts, much red sand in notts.

Lime render isn't always white. Stick to giving overskim advice.