Render Dilemma

[endomorph]

OK so here is the scenario -

Garden wall, 3 foot hight, 18 foot long. One side is soil, other side is the patio area. Built of solid concrete block.

Patio area side has (in layer order)

Tar paper
Render mesh
Render scratch coat
Render top coat
2-3 coats of outdoor masonry paint
1 coat of bitumen sealer
1 coat of paint

The garden side does not have good drainage so over winter the soil gets very wet. And this year it's been wetter than longer.

Anyway, the render is starting to crumble away and paint is starting to lift off in patches and I want to re-do for this summer (if we ever get one)

My questions are -

Can I just remove the loose render and flaky paint and render another coat on top ? If so, what should I do to ensure good adhesion ? scratch it up ? PVA ?

Or should I try and remove it all (paint layers and render) and start again ?

BTW, have tried removing the paint/sealer with a heat gun - not a hope in hell of it coming off.

I cant really put another layer of render mesh on it and render on that as it has bricks topping the wall and I don't have much overhang/thickness left, although if this is the best solution, then that's what I have to do

 

[Micilin]

How practical is it to put anything on the soil side? (Not at all I guess)

Is teh drip on the capping currently covered so redundant?

Could you re-cap it?

Could you have drainage thru the wall?

Stay away from PVA outside.

On the face of it I would remove all , then SBR /OPc Slurry with two coats of SBR render or waterproof render .

 

[endomorph]

Is teh drip on the capping currently covered so redundant?
Erm, do you mean the overhang of the capping from the wall ?

Could you re-cap it?
Yes but wanted to avoid if possible

Could you have drainage thru the wall?
I was thinking of doing this but it's going to make it look fugly

Stay away from PVA outside.
OK

On the face of it I would remove all , then SBR /OPc Slurry with two coats of SBR render or waterproof render .
This is what I thought I will have to do. Never heard of SBR before but looking up it's a no-brainer really

Recommendation on mixture for a good render mix ? [/b]

 

[Micilin]

There should be a groove on the underside of the overhang of your capping. If not then you will always get water running diwn, across and in the hairline crack where render meets capping. This is a common cause of render degrading and often is problem when walls arerendered that were not originally capped to allow for render or re rendered. ( I see a lot of new builds by builders who do not understand this).

Can you check this?