Patching Up a Pebble Wall

[Androlicus]

Hi all,

I've got a very tired looking old wall in my garden which appears to be built from pebbles (possibly from our local beach). The pebbles have fallen out in various places, leaving chunks out of the the wall which I'd like to replace in a similar way if poss. However, I can't work out how they were adhered together in the first place. There seems to be very little mortar holding them - just the faintest can be seen at the point the pebbles touch, if that makes sense. And the pebbles aren't just on the surface, but a few layers deep at least. I'll be lime-washing it after, so could push the stones into a render mix if that's what's recommended, though I'd prefer to see as little mortar as possible.

A couple other bits of info:

- The pebbles vary in size from 1cm to 3cm diameter and are very smooth
- There's earth on the other side of wall
- The wall seems very sturdy, and those stones still in place are held fast.
- I've done a little bit of pointing, but would appreciate your thoughts on mixes, bonding agents, etc.

Hope that all makes sense. My first post, so go easy on me. Thanks.

 

[dann09]

I'd suggest that you are in the wrong forum - ask the mods to take you to Plasterers forum.

Can you post pics - it would help?

Pebble dash is set in wet sand and cement mortar - the pebbles/stone are applied in various ways according to local custom.

It's a relatively simple business to patch up, but could be painstaking for a DIY'er.

 

[Androlicus]

Anyone know how to request the moderators to move this post to the Plasterers Forum? I sent a message yesterday but no response yet.

I've also uploaded some photos of the wall here:

//www.diynot.com/network/Androlicus/albums/16323

 

[dann09]

What you have is pebbles from a beach - it's bad enviromental practice to use them nowadays.
You can buy similar, but not from the local beach or wherever.

Your wall is a pure DIY job - perhaps a thick SBR spread on the bare patches, and then throw/dash the stones into the adhesive.

 

[dpt]

Have you a picture of the whole wall?

 

[Androlicus]

I've uploaded a photo of the whole ugly thing:

//www.diynot.com/network/Androlicus/albums/

Never thought about applying SBR on it's own. Do you think it'd stick them without any mortar?

The pebbles are likely from our local beach, yes. I had intended on filling the spaces with the same.

Thanks for the replies so far.

 

[dann09]

That pebble dash on any retaining wall (esp your's) is just about the worst possible finish to apply.

At some stage it will start to delaminate in sheets.

How about, returning as much as possible of the pebble dash to the beach - the sea will sort it out - and then come back here with pics of the background for further suggestions for a finish? Just saying.

If the background retaining wall is damaged/cracked etc then it might have to be rebuilt anyway and nothing will "stick" for the long term.

 

[Androlicus]

Yikes, that doesn't sound good. I'd rather shot of the whole thing and start afresh but I imagine it's a job for someone else, and I'm about to spend my savings on repairing a leaking bay roof.

Quite a few properties along the street have the same wall however, and despite them looking as tired as mine, they are still standing. Perhaps I forget about making it good for now, and just lime-wash the darn thing.

Does anyone have tips for lime-washing pebbles? I read somewhere that porous surfaces were best for this, so would a masonry paint be better?

 

[dann09]

With respect. No. Thats not the way to go.

For so many reasons, dont lime wash or paint the pebbles - mainly because it will quickly look worse than now.

Perhaps remove all the pebbles, as above, and paint/wash the presumably concrete or blockwork background. The cover is failing, not, AFAWK, the background.

But concentrate on the leaking bay before any of this.

 

[roy c]

I dont know where you get the idea that SBR will allow pebbles to stick to it danno. The wall has been pebble dashed by having them thrown on to a mortar base ,be it sand and cement mortar or sand and lime mortar or sand lime and cement mortar,.I agree it has been done badly but looks like it has stood the test of time and now wants a bit of a face lift. There looks like there are drain holes in the wall so it must be a retaining wall of some sort and they allow the water to drain out.Is that correct? You could see how sound the pebbles are on the wall and possibly throw some mortar on the sketchy parts and throw some "pea gravel on it, just to tidy it up a bit!! Or you could mesh the lot of it and scratch coat it and put what ever finish on it that you want, Or you could put that trellis in front of it and hide it. I know it is a bit of an eye sore but you could patch it up like I said cheaply and throw a few coats of paint over it. It's your call, there are the options, if you have other important things to spend money on then do that first (As long as the wall is not in a dangerous state). Then decided afterwards what option to take to do your wall.

 

[dpt]

I might be wrong but I believe the wall was boxed out and poured. I don't think it's dash. You see it done with shells as well.

 

[Androlicus]

Thanks for those suggestions. Yes the idea was to give it a bit of a face-lift before lime-washing or painting it. And yes, those are drain holes. For the original build, the boxed and poured method seems to make sense (seeing as it's quite deep), and therefore limits what I can do to fix it.

So, I think I'm going to try to add some mortar and fix some pebbles in place just to fill the larger gaps. I'd be interested to know why lime-washing or painting after would be a bad idea? I know the paint will eventually peel, but I can always repaint.

As for concentrating on my leaking bay, my wallet is taking care of that, so don't worry, thanks!