Decorating habits

Dear friends, I would be most grateful if any of you with building / decorating experience in France would be kind enough to offer advice.

In my (approx. 12-y-o) house there are some areas which have been left cosmetically unfinished (garage, utility room). The plasterboard has 'blobs' of white which appear to seal the joins, but do not do so for the whole length because they are discontinuous. I have just had some work done to a bathroom and the finish is the same (though the plasterboard is sea-green instead of grey, presumably because it is a waterproof type?) Here the joins are covered in tape, then some sort of white paint and the 'blobs' are confined to areas of unevenness such as nail holes.

In UK I would expect the finish to be a skim of plaster ready for me to apply emulsion. However there is clearly a different practice here - can anyone enlighten me as to what it is and what I should be doing next please?

Grateful thanks.

Nope, it is the finishing plaster. It just needs a thin coat, perhaps 3mm or thereabouts to finish off the plaster boards. Painting direct on them with the joints, 'blobs' and so on does not work, so you need it before undercoat, in fact should not actually need to undercoat anyway. It is all very different to what you are used to but that is part of the 'game' after all.

Thank you. What am I looking for in terms of undercoat and paint - is it the 'enduit de finition' referred to by our friend Brian above?

We’ve just had the same in our new build. All you need to do is sand the edges with really fine grade sandpaper and then undercoat and voila ready to go with paint. It’s fab

Yes, completely different here but it works as well. Dark green or blue means it is humidity proof, so for bathrooms and the like, it must be an Isover one which is very good quality. I am working on Fermacell myself this weekend, bigger spaces between panels, but no tape on joins, the white paint is a plaster of Paris based primer that you can plaster over or paint directly on depending on the finish you want. My OH is doing plastering next week, she like that job and this time is doing hand application, literally - not skimming it on with rendering tools such as trowels or spatulas, of a chalk based plaster which means it will be a rough (natural) finish. We have helped friends do the same, I have unlearned UK habits (my family were builders, so it took some convincing) and she has unlearned her Italian type ones. So no plaster like a well ironed bed sheet. So, it looks like you need to go out shopping for your enduit de finition and if you want a good one go for an enduit de finition à la chaux aérienne, possibly Weber cal F, if you can find it, which is a treat to work with. Best of luck with it, I'll stick to putting the boards up!