Modern Plasters Help!

[CHRIS]

What are peoples ideas on what to use to plaster over a 1970s kitchen extension, at the moment it is plaster board with a skim coat in cement with all joints taped with scrim tape as in most modern houses but the previous owners painted it all in that awful vinyl silk (in a nasty lilac colour), all the walls are banged and badly filled so I want to skim over but without the smooth finish of Multi finish etc.

I have plastered most of the original part of the house in lime and chalk/sand mix but want to replicate the texture in the kitchen, is BG bonding coat a good idea?

thanks

 

[Andrew Bodenham]

I presume you mean that the original skim is gypsum rather than cement. Anyway, there seems little point in trying to put something "authentic" over that lot.

In a recent renovation I 've seen a 50/50 mix of bonding and multi-finish used to create a slightly rough surface with great success. If you can work in a little uneveness in the surface then you might achieve the soft sort of finish you're after. I think you have to be careful not to create a pastiche of 'rustic' style.

Getting the plaster to stick to the vinyl paint might be interesting - maybe a coat of PVA, or a good keying wth a scratch float might be needed.

You don't say what period the rest of the house is, but one detail which may be worth considering is changing the hard plastering beads on external corners and window reveals for the more authentic wooden beads. It makes a big difference to the look of a room.

 

[CHRIS]

I agree about the worry of trying to look old, but I think a softer look would be much better than a modern polished look, I wonder if using a wooden float would work with a 50-50 bonding and multi board finish?. The idea of wooden beads sounds interesting - was thinking of chamfering the corners of the plaster board and having 1/4 round edges with a radius of about 5mm - I sourced some of that bull nose beading when last in the USA.

http://www.phillipsmfg.com/products/vbt/bull_cornb.htm

I like it so that is all that matters but does give a soft finish similar to how a straw bale house looks. (the house is a 1800 little workers cottage)

 

[BMcD]

Due to the different setting times it is inadvisable to mix pre-mixed gypsum plasters as it can lead to unpredictable sets. An alternative would be to use a one coat plaster http://www.british-gypsum.bpb.com/p...coat_plasters/thistle_universal_one_coat.aspx
which can be applied as a skim or to a thickness of up to 13mm in one go, straightened and troweled to a finish. Of all the gypsum plasters to me this is the one that most resembles lime in both its application and appearance but only slightly.
If you first make sure the background is sound and the paint isn't flaking then coat the walls with Thistle Bond-it http://www.british-gypsum.bpb.com/p...le_plaster_bonding_agents/thistlebond-it.aspx
(not Bonding plaster) leave for at least 24hrs then apply the one coat plaster.

Sorry the URLs are a bit long but I hope they help. The PDF for the one coat tech sheet tells you about application

 

[Willmat]

as well as battening out plasterboard to make the surface look uneven and wavy, you could also load up the plaster in areas first on walls and ceilings - so that when the top coat/s goes on you do have a more authentic looking wavy wall or ceiling.

We had a very modern extension on the old part of the house and this was really quite pleasing. Though obviously not the same as the lime to the experienced/unlightened eye (always the hard part as no visitor would notice but you will!). You can even replicate the ceiling pretty well and as of yet no cracks on the joints. Also avoiding sharp edges and beads looks much better, even to the point of hacking off corners with a bolster.

was intending to try the 50/50 multifinish/bonding mix in the new area but never got round to it. seems to be widely used so would imagine longterm is fine?

 

[NT]

whats behind the PB? If theres no insulation, now might be a good opportunity - or as good as you'll ever get anyway - to strip off the PB, insulate it all properly, then either re-PB or lime plaster it all.


NT