Rendering an old garden wall???? - with pictures....

[DanDIY]

Hi All,
I have a 5ft high brick garden wall that is damp and has quite a lot of blown bricks. The house was built in the 1890's and I believe the wall to be original as all the other houses in the street have one.

I am guessing that some of the damp problem might be related to the poor pointing and blown bricks, which in turn will continue to make the damp worse, increasing the frost damage and blown bricks etc.......

I was going to repoint the wall, but it was never going to look anything special what with all the blown bricks etc... After visiting next door and seeing that their side of the wall is rendered and painted white I thought I may try the same thing.

I would basically like to know if this is possible on a damp wall such as this. I was planning on wire brushing and pvaing it first, but will the render stick, are there any special formulations to use? If it is possible to do this type of work would it be ok to do at this time of year (Im layed off for 2 weeks at christmas ) or do I need to wait until the summer, until it is a bit dryer (although it never seems to fully dry out). Obviously it has worked for next door, but they have the south facing side of the wall, I have the north, and I dont know what condition theirs was in when it was done (apparantly 10-15 yrs ago)

My reason for doing this work is that the wall appears to be structurally sound at the moment and I would like to keep it that way. Some walls further up the road have started to lean and eventually fallen over. They have cost their owners several thousand pounds to put right. I was hoping this work may protect the remaining brickwork and mean I get a good few years more out of the wall.


If for instance the rendering might just need a bit of touching up every couple of years I would see this as a reasonable project to persue. If it is likely that the whole lot will fall off after 6 months then I wont bother!

Any thoughts/advice welcome..... Thanks in advance!

 

[DanDIY]

From looking through some other posts I think this week might be good to start this job, its going to be mild and fairly dry.
I am planning on brushing away any loose debris and PVAing.....I dont really know what to do after this, are there any online guides to rendering an external wall....
Any help greatly appreciated!!!!!

 

[marshman]

you'll have to get the green algae off, but I think you would be better off repointing it clear the soil back lower than the blue bricks
at the bottom, and if you render it don't go below these, don't pva it just scrub it clean.

 

[diggerjones]

i would agree you've got a good looking wall there. it would be a shame to cover it up. just clean it up and point it.
good look diggerjones

 

[Alastairreid]

if it were my wall i would clean it it up give it a coat of pva and roughcast .
Do you think your neighbours spent £100s
for nothing.........? the engineered brick wall has started delaminating time to preserve and protect.........trust me......

 

[tawelfryn]

If I had a wall like that there's no way I would render it. If you do your garden will look too mechanical looking. A wall like that just cant be built to look like that, only time can get that effect. Leave it, with some nice plants/climbers by the side of it, gardens are supposed to be tranquil, not like a building site.
If that wall is structurally sound, it will outlast you, as you mention others have started to lean, if that wall eventually wants to lean, believe me, render wont stop it.

 

[Alastairreid]

JUST A MATTER OF PREFERENCE REALLY!!!.

 

[Alastairreid]

the brickwork is.......delaminating............ie the kiln baked surface is starting to degenerate, the surface is starting to blow off!!!.
to impede further degeneration of brickwork i personally would re-render.

 

[DanDIY]

Wow, lots of discussion there, this is what I was looking for. Thanks chaps.

My concern is that it appears that once the brick face has blown the rate of erosion of the brick seems to increase greatly. Some have eroded in by an inch or more, with the majority of the wall only being one brick thick.

I am not even sure if I have got my terminology right. The neighbors side of the wall has a kind of nobbly finish. My dad reckons it is applied with some kind of rotating drum that splatters it onto the wall??? It is then painted white - looks kind of Mediterranean looking. I would leave the coping stones un coated so as not to totally loose the character/age of the wall.

 

[Alastairreid]

When we do delamination works (to the structures of houses) the brick has blown "or starting to"
it is time to think about creating a new protective surface to maintiin the integrity of the structure......makes sense "dont you think"........i would p.v.a. scratch coat 2nd coat and r/cast to preserve the wall.....i would certainly r/cast to preserve.
30 yrs experience............not D.I.Y

 

[swbjackson]

The finish with the rotating drum is tyrolean.

Mike

 

[tawelfryn]

30 years bricklaying/site engineering/management experience here, render it and you will wish you hadn't. It has eroded, yes, taken over 100years so far, it is caused by the wall continuously being exposed to wet conditions top, bottom, and both sides. Effervescence of the salts continuously being sucked in while damp, then drawn back out through wind has caused some faces of the bricks to blow. If there are a few bricks which concern you, then chisel them out and replace with a similar old brick in good condition. Also weather strike the wall if you like. With the wall being subject to many areas of water penetration, the render will blow off, sooner than what the wall will last just on its own. If its structurally sound, it will last another 100 years

 

[stuart45]

Dan,
The spalled bricks will wear quicker than the others once the face is lost. Frost can also cause further damage. It depends on how many need replacing. Most of the wall looks to be in reasonable condition for its age. If you decide to repoint it I would use some cementone to tone down the colour a bit. I dont think that old walls look very good when re-pointed and the joints really stand out.
The only problem with cutting out the spalled bricks is the damage you will do to the render on the other side of the wall.

 

[DanDIY]

The only problem with cutting out the spalled bricks is the damage you will do to the render on the other side of the wall.

That is a god point, I would end up smashing chunks of render off the other side of the wall. I would then have the problem of having to repair this....trying to match the finish etc.... so I think that is a definite no.
Good job I didnt have the hammer and Chisel out too quickly
Thanks

 

[tawelfryn]

The only problem with cutting out the spalled bricks is the damage you will do to the render on the other side of the wall.

That is a god point, I would end up smashing chunks of render off the other side of the wall. I would then have the problem of having to repair this....trying to match the finish etc.... so I think that is a definite no.
Good job I didnt have the hammer and Chisel out too quickly
Thanks

You cant attack the bricks like a bull in a china shop, if a mini angle grinder was used to take out most of the mortar, then some gentle chiselling, easing the brick out. As the wall is one brick thick, the stretchers will run alongside each other, any headers that need replacing cant be chiselled out as they are going all the way through tying the two leaves together.
Anyway this is just an option, other than rendering it,
the bricks that are deteriorating, from what I see from those pics, still wont do any damage to the integrity of the wall, it adds character, it is not a safety issue, and its not a wall of a dwelling, just a feature dividing boundary wall, which will last years and years, and like I said with some nice climbing plants etc., would help stop a lot of weather hitting it, and would look lovely.