Garden wall paint problem

Bonzo Delaney

Hi mods.
I had this over in " interior decorating " with no joy feel free to delete as appropriate. Thanks.

I've a 9inch capped cavity block rendered garden wall 5ft high and 12 ft long that has a 3ft bank of clay behind it. I put polythene between the clay and the wall. I'm sure there's no dpc under the block work. When the wall was painted with dulux weather shield paint after about two months it all flaked and blistered off due to damp I reckon. Before I scrape it all off and repaint is there any product that would be recommended to seal the render from damp comming through and that'll take repainting.
Thank. For any help.

rolliepoley

Did you damp seal the wall before you put the soil down? if not, your going to have to start again and seal the wall before you can paint.

https://www.google.ie/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=+DAMPSEAL

Bonzo Delaney

rolliepoley wrote: »

Did you damp seal the wall before you put the soil down? if not, your going to have to start again and seal the wall before you can paint.

https://www.google.ie/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=+DAMPSEAL

The only damp seal I have is 3ft high by 12ft long of 1200 gauge polythene between the bare block wall and the clay. Was just wondering is there anything that's proven to work I could prime/seal the outside plaster coat with and that'll still allow me to paint over with the dulux weather shield.

rolliepoley

Is the whole wall flaking or top or bottom?

You will still get water coming from the other side, seal both sides and also i would drill some drain hole on the plaster side to drain excess water that builds up in the block cavity.

slimjimmc

When painting the wall for the first time did you remember to seal the raw render with diluted paint for the first coat ?

Bonzo Delaney

The paint was diluted about 50%
It's flaking from the bottom up
Might have to look going down the drainage route
Was hoping to find a product such as Thompsons exterior water seal but with the addition of been over paintable.
It'd save me a lot of digging.

rolliepoley

Have a look here.
http://www.plascon.co.za/products/product.asp?SectionID=1&RangeID=5&ProductID=30

Could you not move the soil back or dig a channell to let the bottom of the wall to dry out? And start over with the damp seal and paint.

Bonzo Delaney

rolliepoley wrote: »

Have a look here.
http://www.plascon.co.za/products/product.asp?SectionID=1&RangeID=5&ProductID=30

Could you not move the soil back or dig a channell to let the bottom of the wall to dry out? And start over with the damp seal and paint.

Yeah I think I'll go down that route and sort the problem at the source. Put in a bit of drainage pipe also to divert any settling water away quickly. Was just hoping for a lazy quick easy way out. Thanks.

rolliepoley

Or you could blow torch the bottom of the wall to dry in out, and try the sealer and paint to see it that works before the dig.

whizbang

Drill some vent holes in the top blocks to ventilate the cavity also.

bman1

There's also a product called impervo by chemsearch. We sell it at work but it's expensive, you could be paying between €120-140 for 5 ltrs. I'm trying to remember if it's an interior or exterior product though. Sure maybe google it.