Repairing holes in a rendered wall

[dominoman]

At the front of my new house is a low garden wall which looks like it was built from brick and then covered in smooth render. In the last year there have been holes appearing where the plaster has popped off.

How easy would it be to repair as a DIY job? I've never done plastering or work with cement, but am willing to try.

There seems to be a metal ridge along the top and this is corroded. Does that need to be replaced?

Some pics below:

garden wall with holes in cement

• dominoman
• 14 Apr 2015
• 1

garden wall. Rusty edge

• dominoman
• 14 Apr 2015
• 1

rusting metal edge pushed out cement

• dominoman
• 14 Apr 2015
• 1

rusting metal edge pushed out cement

• dominoman
• 14 Apr 2015
• 1

 

[ree]

There are a number of faults in the retaining wall:
1. the wall should have been capped with coping's.
2. plastic angle beads ("metal ridge") should have been used.
3. The top edge (without coping's) should have been sloped to shed water.
4. the regular pattern of spelching render patches indicates some kind of underlying fault - in the brickwork, or pressure from the back soil etc?
5. the render should stop short of ground contact.
6. no weepholes are evident?

You could patch with a simple 3:1 mix of sand and cement (buy a bag from a plumbing supplies) but it would only be a temporary fix.

 

[dominoman]

Many thanks for the reply. Sounds like there is more to do than I thought!

Would it be better to hack off all the render and render the whole thing again, using plastic angle beads?

Or as a half-way fix, perhaps just hack off the top where the corroded angle bead is and replace that. I imagine I could cement a new one in fairly quickly that might last a couple of years at least?

I like the more minimalist look of the wall without coping stones. Will it stand up OK so long as the top is angled slightly?

 

[dominoman]

6. no weepholes are evident?

You could patch with a simple 3:1 mix of sand and cement (buy a bag from a plumbing supplies) but it would only be a temporary fix.

Yes - there are no weepholes. Like many things in the house the wall seems to have been poorly built.

Is it necessary for me to put new weepholes in? It's quite a low wall so the water should eventually drain down into the soil behind the wall I'd have thought?

 

[ree]

Its your call whether to hack off and re-render. You might find v. poor brickwork below or not even brickwork.

weepholes - same as above.

No coping - same again. Your call.

 

[dominoman]

I think I'd find it easier to hack off just the worst areas, clean it and then re-render with a cement mix.

If I do this as a DIY job I could then lay coping stones on top. Something like this: http://www.albionart.co.uk/assets/images/copingpic.jpg

Presumably, if i use coping stones then getting a nice straight edge on the angles is less important, as it wouldn't be visible where the coping sits on top of the wall?

 

[dominoman]

Can I use the same 3:1 mix of sand and cement to fix on the coping stones as I use to fill the holes?

 

[joe-90]

Stop messing around, it's an old wall. Just patch it up with a cheap mortar mix. Forget all the rest of the rubbish, do that when you rebuild it in 20 years time.

 

[dominoman]

One final question before I attempt my patch up job... If I lay coping stones on top of the wall would they need pointing? And what cement mix would be suitable for that?

I have seen some places online that say pointing isnt needed, but in that case water could just sit between the stones.