Identifying lime render vs cement.

[klang]

Long story first....
I've just removed some failed cement render, along with a base coat, and rusty old mesh from the side of my house.
It was a bodge job when applied 25 years ago and probably failed 20 odd years ago, when a chunk fell off.
I think it's been causing damp problems ever since.
Now it's gone though, it's revealed a thin grey render, that was probably applied when the house was new, in the late 40s.
It's hard, and brittle, and I suspect it's cement.
However, the house was built during post war shortages, and the mortar in the garage brickwork seems to have very little cement in it.
(When I raked out the garage mortar it had turned back into sand.)
That makes me think the builders would have minimised the use of cement in the render.
I'd like it to be lime render, as I think it would be easier to remove, and also that it would allow the house to breathe again.
(I have a mold allergy, and my breathing seems to have got better)
Here's the question...
I've just soaked a fragment of it in white vinegar, and it's fizzed a wee bit, but not exactly like an alka-seltzer.
It's too dark to photograph the wall now, but I've attached a pic of the render in white vinegar.
Does it look like it's fizzing enough to be lime?
(Also, it soon softened up after being soaked in vinegar)

 

[Wayners]

This isn't my area of knowledge but...skillbuilder... Have covered lime mortar and render really well so go and watch.

From what you have said I think that's got lime in it.
Maybe what you have has a little cement in it along with lime?
You thinking about having all replaced?

 

[klang]

Yes, I'd like it all removed, but the wall has other issues, and I'm going to get a brick survey done soon to get a better idea.
There's a few cracks in the masonry, and a lot of spalled bricks low down.
There's also no cavity insulation (which might be a good thing)
The full job will be brickwork repairs, insulation (CWI or EWI), and an external refinish of some description.
I think I've got a few options, and they won't all need the render blasted off.
Off the top of my head, I could have CWI and new silicone render.
EWI with cement on top.
EWI with cladding.
Or even a new outer brick leaf, with CWI and a wider cavity.
Sorry for the long answer, but nothing's ever easy (or cheap!)
Cheers.

 

[noseall]

Yes, I'd like it all removed, but the wall has other issues, and I'm going to get a brick survey done soon to get a better idea.
There's a few cracks in the masonry, and a lot of spalled bricks low down.
There's also no cavity insulation (which might be a good thing)
The full job will be brickwork repairs, insulation (CWI or EWI), and an external refinish of some description.
I think I've got a few options, and they won't all need the render blasted off.
Off the top of my head, I could have CWI and new silicone render.
EWI with cement on top.
EWI with cladding.
Or even a new outer brick leaf, with CWI and a wider cavity.
Sorry for the long answer, but nothing's ever easy (or cheap!)
Cheers.

Go for a modern bagged polymer render. You won't regret it.

We had to remove a strip (new wall abutment) recently and it took ages even though we had scored the removal zone first.

Class gear.

 

[^woody^]

Vinegar is not an accurate test. Lime plasticiser or natural carbonates in the mix can cause it to fiz. If you need to know for sure it should be laboratory tested.

Generally, a grey shade would tend to indicate cement, as would a finer, denser grain appearance and it being harder and pieces being less friable - hard or brittle and not crumbly