Why sharp sand for rendering?

[Mary Fisher]

That's another good reply.

I wish I'd had you lot around when my dad used to tease me with this!

Mary

[Mike]

It is while you are building it. I know of cases of people round here being killed doing so.

Also they are when ******* ramblers stand on them for a better look when then climb over the stile meant for this purpose.

There is still one good use for foxhounds.

[Roger]

The message from "Mike" contains these words:

Not in my experience. I confidently stand on incomplete walls when I build them.

200 year old walls where the cowboys who built them didn't as much as strip the turf off the ground before throwing them up are a prime candidates for collapse but a well built wall on subsoil that has not been abused has as much chance of lasting as a mortared wall.

[Mary Fisher]

I don't. so what does that prove?

People are killed on building sites of all kinds.

Anything can be dangerous if misused.

Mary

[andrewpreece]

Mortar is used to spread the stresses between bricks evenly; you could use dry sand were it not likely to dribble away. No masonry structure relying the tensional strength of mortar will stay up for long. I have seen a Roman aquaduct in Spain constructed of stone only, no mortar. Friction and its own weight keeps it together. In order to forestall problems with uneven stresses causing cracking though, they had to shape the individual stones to fit each other quite accurately.

Of course with bricks, since they are relatively light, a little bit of tensional strength in the mortar does no harm, especially on the lightly loaded upper parts of walls.

Andy.

[Mike]

All I can say then is "Are you near the Peak District and are you looking for work."

[Mike]

Quite possibly. But the fact is most dry stone walls are on dodgy footings and any abuse causes them to fail.

[Mary Fisher]

Evidence?

(not anecdote, opinion or personal experience)

[Roger]

The message from "Mike" contains these words:

Not exactly on either count. I am not a professional dry stone waller (and slow) and have sufficient lengths of my own wall (several 100 yards) not to want to get involved with other peoples.

[Mike]

What sort of evidence will you accept then ?

I personally own several miles of dry stone wall and both cattle and ramblers damage it regularly. As soon as they're damaged in the slightest way they seem to deteriorate into a pile of stones amazing rapidly.

[Mary Fisher]

Perhaps they weren't well built in the first plce or not well maintained ...

But you said " ... most dry stone walls ... "

Your own experience is not valid in this context.

Mary

Mary

[Rob Morley]

tensile :-)

[Mike]

Would you accept a comment from the Peak District farmer's association then ? That would cover possibly 20% of dry stone walling the country and a far higher percentage of ramblers.

[Roger]

The message from "andrewpreece" contains these words:

Lime mortar can wash out of the joints on exposed walls (the outer skin of the gable end of my barn has an area of about 10 feet square with almost none in sight) but the Romans were dab hands at making a cement mortar that could last 2000 years even exposed to the elements.

[Mary Fisher]

LOL! It might also say more about the maintenance in the Peak District than anything else :-)

Mary

[Mike]

I think what it shows is there is a distinct shortage of dry stone wallers to undertake maintainence and repair work, hence my offer of work to the other poster. I doubt if the situation is any better elsewhere though I accept I don't visit those areas and cannot judge.

[Mary Fisher]

Indeed. Not the integrity of a wellbuilt stone wall.

Quite. That's the danger of words like "most".

We all do it ... :-(

Mary

[Anna Kettle]

Not once it is set it can't. What you are seeing is the results of sacrificial weathering which is a GOOD THING and you should be inspired to repoint your gable end come springtime

Roman cement is not cement as we know it today. Today's cement is produced at much higher temperatures and is much harder and stronger than Roman cement. If you want the Roman cement effect today then either use a feebly hydraulic lime mortar (NHL 3.5) or use a lime putty mortar with 20% of the aggregate being a pozzolan. The Romans used volcanic ash as a pozzolan, but brick dust is more readily avaiable in England

Anna

~~ Anna Kettle, Suffolk, England |""""| ~ Lime plaster repairs / ^^ \ // Freehand modelling in lime: overmantels, pargeting etc |____|

01359 230642

[Roger]

The message from [e-mail] (Anna Kettle) contains these words:

I am more inclined to tear down the outer skin of that section of the gable end and rebuild. It will probably be quicker than squeezing bucketfuls of mortar into the gaping holes that smile at me as I pass and being stone it should all be reusable. However any action on that wall is some way down the pile of tuits (round).

Brick? What's that?

I haven't been close to original Roman walling lately to test how hard it is but I don't rate cement mortar as hard (except when compared with lime mortar). There are a good many examples of Roman masonry that have survived 2000 years. That bit of my gable end has lost its mortar in 400 or possibly much less).

[Mike]

Consider finding and hiring one of those render sprayers they used for spraying lime render in a recent Grand Designs.

That's not bad going really, is it. The average Barrett hutch will have crumbled to dust in half this time. Or even less hopefully.