Cure for Mud Cracked Walls

[be11aml]

Hi, I am about to try cover/repair some quite serious mud cracking in one of my bedrooms.

This occurred after I tried to repaint the room after moving into the house. The original paint (i think) was vinyl silk, on sanding to remove the sheen, the paint seems to be be 'melting' and balling up under the sander. Not a good sign!! On one wall, the old paint peeled away entirely.

I wiped the walls down and applied 3 coats of matt emulsion, but the paint has cracked on practically all the walls, except the one that peeled away. I can see through the new paint to the old layer and I am sure that painting over will not sure this issue.

I would like to put this right, but can not find any definitive advice.

Please help

 

[Third_Eye]

What is the exact name of the Matt Emulsion ?

 

[be11aml]

Hi, thanks for the response.

The matt emulsion was Crown Breathe Easy matt emulsion and the shade was bliss.

On closer inspection in my bathroom, I am seeing the signs of similar issues. In this case I used Crown Once matt emulsion.

I think all the paint in the house was vinyl silk (Focus brand), as this was left in the garage when I moved in.

Thanks for any further help

 

[billyo]

if you put the paint on stright from the can, as you said, and applied three coats , and you can still see through it i would complain to who ever i bough it from, and email the manufacture there is something serious wrong with that product

 

[spice]

Hi, I am about to try cover/repair some quite serious mud cracking in one of my bedrooms.

This occurred after I tried to repaint the room after moving into the house. The original paint (i think) was vinyl silk, on sanding to remove the sheen, the paint seems to be be 'melting' and balling up under the sander. Not a good sign!! On one wall, the old paint peeled away entirely.

I wiped the walls down and applied 3 coats of matt emulsion, but the paint has cracked on practically all the walls, except the one that peeled away. I can see through the new paint to the old layer and I am sure that painting over will not sure this issue.

I would like to put this right, but can not find any definitive advice.

Please help

This occurred after I tried to repaint the room after moving into the house. The original paint (i think) was vinyl silk, on sanding to remove the sheen, the paint seems to be be 'melting' and balling up under the sander. Not a good sign!! On one wall, the old paint peeled away entirely.


I think the problem lies with the original Vinyl silk, I expect when the walls were originally painted over new plaster, whoever painted them didnt do a miscoat of matt first.
They probably just went Gunho with the silk.

if this has happened in different rooms like you said, and using different paint, then I feel the problem lies with the existing paint.

You have a few options....

You can either scrape all the paint off.
Or apply a coat of soft sheen, watered down, then apply the matt.
Or, buy dulux alkaline primer sealer, (very pricey)
Or, undercoat the whole lot using oilbased undercoat, but diluted with white spirit.

I have used every one of these methods over the years, and I am not telling you what one to go for, but under the threat of torture I would have to say the undercoat is the one I would definately plump for.
Plus, its a hell of a lot cheaper than the others, and goes a lot further, and I used this method a lot more often than the others.

Get some cheapo oilbased UC, its good enough for this.

if your not too sure, then try it on one area first, but it will do the job.

Dont forget to still do your sanding down first to get rid of the jaggy edges, and make good where necessary.

If you do any filling, dont roll over the filler, just dab some diluted UC on the filled bits, and roller the rest.

Let us know how you get on.

 

[be11aml]

Now that was a great answer and very helpful!!!

I will certainly provide an update in the future and many thanks.

 

[joe-90]

I'd go for the oil based undercoat too. The reason for the blisters is that the silk absorbs some of the water out of the matt coat and expands. It has nowhere to expand to so it forms a bubble. Oil based paint will not cause this to happen.

 

[spice]

I'd go for the oil based undercoat too. The reason for the blisters is that the silk absorbs some of the water out of the matt coat and expands. It has nowhere to expand to so it forms a bubble. Oil based paint will not cause this to happen.

Great explaination Joe, could'nt have put it better myself.

 

[Third_Eye]

Hi, thanks for the response.

The matt emulsion was Crown Breathe Easy matt emulsion and the shade was bliss.

On closer inspection in my bathroom, I am seeing the signs of similar issues. In this case I used Crown Once matt emulsion.

I think all the paint in the house was vinyl silk (Focus brand), as this was left in the garage when I moved in.

Thanks for any further help

Crown Breatheasy in my personal opinion is cheap **** retail emulsion.

It is very simular to Dulux Rich Matt.

Hence why these both paint companies are competing to be the cheapest white or colour for whatever. However, Crown just bought Dulux !

The problem is with the Crown Breatheasy as it can only cope with an surface in which it has a slight to moderate suction i.e. previously painted matt(s) emulsion(s) surfaces. Apply it to an washable emulsion sheen emulsion then it can mud crack. Even years down the line.

Also, you explain you have the same problem with Crown Once Matt Emulsion. This is caused as ALL ONE COAT EMULSIONS are to thick to be paint. It should be taken off all shelves.

Also, "spice" gives you great advice. However, unfortunatly by using Oil-Based Undercoat to fix your problem then this can also cause longterm problems. It can make future coatings to blister in small tiny bubbles when applying certain emulsions etc.

You would be best going with Alkali Primer Sealer.

 

[spice]

[

Crown just bought Dulux !

Crown havent bought Dulux, Dulux has sold out to a french firm, I think they are french, but they wont be able to sell both crown and dulux, or even make make both.
They can just have the one name, ie, 'Dulux crown', but they will be closing down some of the plants, but we wont know for a while whether Dulux or Crown pulls the short straw.

BTW, good advice as usual.

The downside of the alkali primer is that its quite shiny, and stinks to hight heaven, and very very pricey.

 

[Zampa]

I'd go for the oil based undercoat too. The reason for the blisters is that the silk absorbs some of the water out of the matt coat and expands. It has nowhere to expand to so it forms a bubble. Oil based paint will not cause this to happen.

So why doesnt matt (which is far more absorbant than silk) do the same?