Lime Plastering

[fathersymes]

I have recently bought a small georgian house. This is the state of some of the walls:

Previous owners hacked off large parts of plaster on some walls (6ft x 8ft) areas. I am considering doing the following:

Fixing vertical wooden battons(2x4) to the wall at 12in intervals and apply Lime plaster. I will obtain lime putty and mix sand,hair as to correct proportions. The idea being that it will be easier to get a level and smooth finish with the battons in place as guides. I will employ a professional to apply the final skim coat.

Am I being naive in thinking I can bring the plastering to this level?

 

[Gervase]

Running plaster to battens using a feather-edge or derby is perfectly acceptable (I do it myself!), but 2x4 is a bit hefty - you're going to be using a heck of a lot of plaster to fill that.
Better, I would suggest, is to use dots and screeds, and save the batten for the bottom, where it can be used later to fix your skirting.
Using a plumb line or a 2-metre level, find the verticals on your wall at intervals of about 1200mm (or just under the length of your feather-edge/derby).
Put a dab of plaster at top and bottom (or use your batten as the bottom datum) and set a little offcut of wood or ply the sixe of a matchbox in the plaster, using your level to ensure that the faces of the offcut are perfectly aligned top with bottom and left with right. On the average wall you'd end up with a little raised dot at each corner and two in the middle near floor and ceiling. Aim to keep the average distance from the wall to the imaginary straight line joining the dots to around a couple of centimetres.
Once the dots have set, you fill in the gaps between them to make screeds, as you can see in the picture below.

Resting the end of your feather-edge or derby on the dots, you can see easily if your screed is plumb and square.

Once the screeds have gone off (overnight usually is sufficient), you can fill in the rest of the wall, using the screeds to guide your feather-edge/derby.
That way you'll get a nice plumb and square wall without having do dig large baulks of timber out of your fresh plaster.
The little bits of ply or offcut that made the faces of your dabs can be left under the finish plaster, or you can prise them off if you want.

 

[fathersymes]

Thank you very much Gervase, that is a great technique. Another question for you, just so as I am on the right track.

The old plaster is still present on parts of the wall, so therefore I can use this as a screed? and level with the Darby.

 

[BMcD]

fathersymes, Gervse has pretty much explained the textbook method of setting out a wall to be plastered. Of course if you have existing sound plasterwork then this should be used as your guide from which to rule off although you must remember to recess the new floating coat a couple of mm below the existing finished work so as to leave room for the setting coat to finish flush with the existing.

To follow on from Gervase's explanation of setting out screeds, you can also use door/window frames as grounds from which to rule off or set out any other screeds from. External angles can be achieved by nailing a plank to the return face of the angle so as the edge of the plank protrudes beyond the face of the wall to be plastered the required thickness of the plaster and plumb. Repeat this when you come to do the return face and hey presto one external angle. Nail heads should be left proud of the plank so as they are easy to prise out and the plank should be slide along the face of the wall to which it was nailed and away from the fresh plasterwork to avoid damage upon removal

 

[Nemesis]

I note the chamber pot casually hanging from the ceiling in one of Gervase's pictures.

Is this ready for installation as an under the bed en-suite facility?