DIY Doctor UK DIY Forums

Can anyone advise me about the sudden appearance of the outline of cavity blocks on my interior lounge walls. The outlines look like shadows on the walls and are dusty grey.

I want to redecorate and do not know what to do to ensure this problem does not happen again.

Advise would be very much appreciated.

Regards

Bibien

[quote="bibien"]Can anyone advise me about the sudden appearance of the outline of cavity blocks on my interior lounge walls. The outlines look like shadows on the walls and are dusty grey.

I want to redecorate and do not know what to do to ensure this problem does not happen again.

Advise would be very much appreciated.

Regards

Bibien[/quote]you don't say how the wall's are plastered,sand & cement & finish coat or carlite bonding & finish coat,what ever if you put 2 coat's of pva
diluted, 3 part's water,1 part pva and allow to dry between coat's that will hold it back. good luck

You have postedcthis enquiry in 5 different sub-forums. Once is enough frankly and SB has given you one possible answer in one of the threads. I'll come back to it later as I have to go out for a while.

Cheers

Hello BrickPat

Thank you for you advise. I don't know the type of plaster on interior wall.
As Stoneyboy has suggested this is caused by cold bridging, My exterior walls are bricks ,then the cavity walls, which were insulated when house was built in 1986.

Will painting the interior walls as you have suggested stop the cold bridging problem. Is the pv solution clear if so what can you suggest I use as a base coat to cover the grey shadows before applying the emulsion.

Thank you so much for your help, between you and stoneyboy I may well be able to solve my problem

Bibien

Hello Rosebury

As I am new to this site and did not know which forum might be able to help I thought I would cover all bases. I certainly would not wish to abuse the site and am very grateful for any suggestions that throw light upon my problem.

regards

Bibien

[quote="brickpat"][quote="bibien"]Can anyone advise me about the sudden appearance of the outline of cavity blocks on my interior lounge walls. The outlines look like shadows on the walls and are dusty grey.

I want to redecorate and do not know what to do to ensure this problem does not happen again.

Advise would be very much appreciated.

Regards

Bibien[/quote]you don't say how the wall's are plastered,sand & cement & finish coat or carlite bonding & finish coat,what ever if you put 2 coat's of pva
diluted, 3 part's water,1 part pva and allow to dry between coat's that will hold it back. good luck[/quote][quote][the outline of the block's on your wall are the morter bed's and cross joint's,bibian the "pva"is white in colour in the can,when applied to the wall it dries clear,also why don't you line your wall's with lining paper,that will be a belt and braces job you can't go wrong .drink up

Hello BrickPAt

Thank you so much for for suggesting a way to resolve my problem.

Between you and Stoneyboy (other forum) I have gained insight into the cause , and also a way to eradicate the shadows.

Your time and suggestions are very much appreciated.

Kind regards

Bibien

It seems to me that what we have here might be pattern staining caused by very fine dust settling on the cooler surfaces. You can also see this sometimes on ceilings where the joists show through. If you can wipe / wash it off then thats what the problem is. Clean it all off with sugar soap and repaint.

The only real solution is more insulation but a repaint every few years is probably more likely.

I'm afraid that I can't see how applying PVA will cure this at all! PVA is glue!

Cheers

Hello Rosebury

Thank you for your suggestions.

Regards

Bibien