Idiot's Guide to rendering and plastering

[Lumaca]

Help!

We had planned to do some DIY cosmetic improvements to our kitchen as we can't afford to have it ripped out and put back in - which is really what it needs - but, on removing some plasterboard facings (which were already loose), we discovered damp behind.

We have dealt with the source and have stripped the walls down to bare brick on a builder acquaintance's advice. The top corners have revealed polystyrene balls (some sort of pumped in insulation I believe) that we don't know what to do with and otherwise we're now left with very uneven bare brick with fairly substantial holes scattered throughout (1" by 3" and depths varying from 1" to 8"!).

The sand and cement is bought and ready to go, as is the PVA.
However, we don't have a clue what we're doing and can't afford to pay someone.

Can anyone give a brief step-by-step on how to render then finish coat the walls please?

To match it with the render that did not need ripped out, a depth of 2-5cm will be required (old house = uneven walls, so depth is different at different points).

Would also really love clarification on the need for plasticiser and lime please.

Thank you for taking pity on idiot in advance!
L

 

[jrplastering]

i think your in too deep im afraid sorry but mabey if you was just skimming for the first time that would be fine but float and set sand cement lime over an uneven substrate........sorry but its a ticking time bomb get a professional in

 

[Lumaca]

Would love to but it's not an option.

We currently have bare brick, a mass of rubble, no money and 3 small children. Any advice other than 'get a professional' would be very gratefully received. We have no option but to do the best we can so will be ploughing on regardless.

Here's what we're thinking:
1. Diluted PVA to prime walls.
2. Stronger PVA then, while tacky, scratch coat of cement/sand
3. Allow to dry then next coat of cement/sand
4. Allow to dry then skim with finishing plaster

Here are my (many) questions:
1. Do I need to fill the holes before I can do scratch coat or just do all at once?
2. Do I need plasiticiser?
3. Do I need lime?
4. Do I put another coat of PVA on between the cement/sand layers
5. What's the maximum thickness a layer of cement/sand can be? (ie do I need to do more than 2 layers on areas which are more than 3cm deep)
6. Do I need to dampen the walls as well as PVA
7. Do I need to dampen the scratch coat before doing the next one?
8. Is more than 1 skim with finishing plaster required?

We really are committed - as much as we might not like it - so any help with any of these could save us a lot of heartache.

With thanks,
L

 

[roughcaster]

i think your in too deep im afraid sorry but mabey if you was just skimming for the first time that would be fine but float and set sand cement lime over an uneven substrate........sorry but its a ticking time bomb get a professional in

Sorry Lumaca, but i think JR has said it all . The best thing you can do is to get a local plasterer in for an "on site" discussion/advice about your job.

 

[peaps]

Would love to but it's not an option.

We currently have bare brick, a mass of rubble, no money and 3 small children. Any advice other than 'get a professional' would be very gratefully received. We have no option but to do the best we can so will be ploughing on regardless.

Here's what we're thinking:
1. Diluted PVA to prime walls.
2. Stronger PVA then, while tacky, scratch coat of cement/sand
3. Allow to dry then next coat of cement/sand
4. Allow to dry then skim with finishing plaster

Here are my (many) questions:
1. Do I need to fill the holes before I can do scratch coat or just do all at once?
2. Do I need plasiticiser?
3. Do I need lime?
4. Do I put another coat of PVA on between the cement/sand layers
5. What's the maximum thickness a layer of cement/sand can be? (ie do I need to do more than 2 layers on areas which are more than 3cm deep)
6. Do I need to dampen the walls as well as PVA
7. Do I need to dampen the scratch coat before doing the next one?
8. Is more than 1 skim with finishing plaster required?

We really are committed - as much as we might not like it - so any help with any of these could save us a lot of heartache.

With thanks,
L

Forget the PVA and PM me, I will see what I can do for you.