Advice Please on How To Solve This Situation

[j_uk]

I have a small study and now that the windows are in, its not clear how best to render the walls, some with existing plaster (25mm - 30mm deep). The backboxes are flush with the old plaster level.

The builders want to do option 3 below, but other options might be:

1. Remove old plaster, back to brick, then dot & dab with plasterboard? However, the old plaster is quite hard, a cement plaster mix, so the face of the brick likely to be lightly damaged; does this matter?
2. Dub out levels, tape joins and then apply render & skim finish (bonding the old plaster appropriately)? Should it be possible to achieve levels relatively easily? Would cracks open up and the overall finish be impacted?
   
3. Dot & dab to existing plaster, which reduces the width of the room further (40mm forward of the old plaster level and back box), and up to 70mm to the brick in places (not great for fixings in the future)

I'd appreciate some experienced advice on this. Thanks!

 

[CTPlastering]

1. Would be best , obviously dearer or more work for the builder plus rubbish etc . If the walls are all over the place alot easier to dab on top than to bond them out if you are working to existing bumps etc but can be done .... What did the builder price for ? 40mm etc on one wall ? Boards are 12.5mm skim 3mm plus the amount of dabs on the back to make plumb but these can vary depending on the shape of the wall . Either way dabing etc isnt good for fixtures unless there is dabs behind the board where you are fixing something to , other wise it can bend the board or snap it if fixing something heavy hope this helps !

 

[raytheplasterer]

is that a cavity wall or solid wall?

 

[j_uk]

Thanks for the quick responses!

My preference is option 1 too; there aren't too many levels to match up, so can't see option 2 being unachievable either. Attached is photo of the other affected wall; as you can see it's only one section of old plaster, so only one level to address.

The wall to the right I am told is a cavity wall, but I don't think the cavity is very big. The other is just two leaves of bricks with no cavity. Both walls are the work of previous builders many years ago before I had the house.

 

[CTPlastering]

If its solid brickwork you will probably get damp problems if its just dabbed , option 2 wouldnt end up as flat at 1 or 3 unless they are bang on the money

 

[johniosaif]

Patch with renovating and skim,
Ps are you the builder, all the options have faults,,

 

[casplas]

your plasterer would/will sort this out for you without all the headache you are going through, by seeing the job in person he/she would work out best procedure looking at a picture of a wall doesn't show much ,there is 22,000 members on here and you could get 15,000 different methods to do the job all of them correct for person doing the work, or have a go yourself mess it up then call a plasterer in , you have a idea on what your doing by your questions and your own answers ,good luck with it

 

[j_uk]

I've been quoted for option 2 (dub out to achieve levels on exposed brick and block wall surfaces, and unibond & skim existing plaster surfaces). Now they want to do option 3, which looks the most expedient, but I'd prefer option 1 to maximise the room width, keep the window reveals to typical proportions, and avoid 2nd fix issues with deep back boxes and voids behind the plasterboard.

On the solid brickwork and possible issues of damp, I'll discuss this with them. Maybe this should be rendered differently to mitigate this?

No, I'm not a builder, but a) want to remove previous issues where possible and b) have seen good plastering (and wish I had the skills).

I'll post an update, maybe even the finished result when we get there.

Thanks all.

 

[raytheplasterer]

what was you previous issues?

 

[j_uk]

Non-plastering issues, like:

• no insulation between the floor joists (just bare earth and some polystyrene over it) - now 50mm celotex between joists, taped & sealed
  
• encasement windows from 1980s (and not particularly good double-glazing) - now DG sliding sash windows 4/4/4 energy efficient units
• headers of concrete flashing, wooden cills - now Bath stone headers, and re-constituted cills to be painted white
  
• cheap door with glazing, hung to swing out into the hallway - now reclaimed door, architrave to match remainder, and hung the right way
• and so on...

...literally anything you could think of, they had done it as quickly and cheaply as they could.