Hi Jenny

The best product for this problem is zinza bin, a remarkable stain block that is perfect for your problem.

Hey Jenny

Zinsser BIN stain block is indeed a very good, yet VERY expensive stain block especially if you have a large area to cover!
I used a similar yet just as effective product from my supplier Johnstones.
As long as the stain block you apply is Shellac based (it's a oil from a beatle) then it'll successfully cover your problem area. Most will dry in 15 mins. Any really heavy dark stains may need to have two coats prior to painting. Apply with very short pile 4"roller otherwise you'll most likely leave brush marks that will require sanding prior to painting.
Good luck.
😊😊
Rob
RSJJ painting and decorating

Hi there! First and foremost make sure you have cured where the leak is coming from and that your walls are completely dry otherwise any paint system will fail. For the bare plastered areas make sure you use a watered down coat of contract matt (any trade brand will be fine, I tend to do it 50/50 with water for the first coat to make sure it soaks into the plaster so it won’t peel in the future).

Once the contract matt has dried use any form of Oil/Shellac based stain block to cover up the yellow water marks I would recommend Zinsser Bin its the best product I have used by a country mile! (Pricey but worth every penny!) 2 coats of Zinsser will do the trick. Also make sure you use a short piled mini roller just to make sure you don’t see any contrasting finishes between coats.

Once thats completely dry use any whichever top coat you choose to go with 2 coats will give you a great finish and your water marks will be gone! With regards to your bathroom I’d use a durable finish such as Dulux trade Diamond Eggshell or if you are painting it white Zinsser do a product called Perma White which has an antibacterial additive in which leaves a great durable finish and also stops mould growth etc. For the landing any kind of trade emulsion Matt or Silk will be fine.

Hope this helps! Best of luck!

I Use a product called Everbuild stain block which it £6 per 400ml spray tin from toolstation. No over spray, the tip sprays in a vertical pattern and you simply spray and sweep the coating over the stain. The product dries within 15 minutes, dries a very bright pure white base matt colour which then ready to paint. Job complete in minutes.

Hi you can buy an aerosol version of stain block from B&Q for about £9 either Zinner or Ron seal and if you give the stain 1-2 coats with the aerosol and then let it dry and apply 2 coats of paint afterwards that should get rid of the stains