The dark art of mortar pointing - Getting it right

[J McNulty]

Been browsing main site pages (again). What's the purpose of a

"vee pointer"

compared to a normal one?

Thanks again

[blackspaven]

Quick question, how do you do a flushed joint with a trowel without getting mortar over the slabs?! Surely it's just pulling the trowel along the height of the slab edges so that it sits flat in it but can't see from having not done it before how you avoid it draggin onto the slabs??

[bespokemasonry]

Do it carefully

[lutonlagerlout]

guys a day like today is a prime example
if you had mortar pointed today you would be bang in trouble round about now with heavy rain coming
we weatherpointed around 50M2 yesterday in the rain and that is that
its in going off and there is no staining
cavaet emptor
LLL

[DNgroundworks]

I never use a rounded jointer, i cut in down both sides with a pointing trowel.

[Tony McC]

What's the purpose of a "vee pointer" compared to a normal one?

There is no good reason to use a vee iron rather than a half-round when it comes to pavement pointing, but they do have their uses on vertical masonry.

On a horizontal surface vee-joints allow water to hang around too long and they create a joint that rapidly fills with detritus. Half round is a better option, and the shallower the better. Flat (aka weatherstruck) is the best option as there's nowhere for surface water to pool and nowhere for crap to accumulate.

Using the blade of a trowel to create a struck joint inevitably results in a surface that is ever so slightly angled. This is not necessarily a bad thing, but if you have a fancy for a truly flat joint surface, there are flat irons available. For occasional pointers and DIYers not wanting to spend money on a tool they'll only use the once, put a 45° kink in a short length of copper pipe and flatten one end with a hammer.

[blackspaven]

Back of a spoon sounds like a good option for different sized joints then!! The flattened copper sounds like a good method though.

So what is the ideal sort of few days for jointing with mortar then? Absolutely bone dry? And how long does it take to go off, ie, how many rain free days do you realistically need to avoid horrors?

[Tony McC]

Dry, overcast, humid for the first 24-48 hrs.

Too hot and/or too sunny and the mortar dries rather than cures, resulting in a weaker mortar and lots of nasty shrinkage cracks.

[blackspaven]

yup, seen a few new patios in other people's gardens lately which look like they were jointed during the tiny, tiny hot spell we had and the flags have tiny, tiny cracks alongsidethe mortar. Hey ho.

Annoyingly, today would be perfect if it wasn't for the suspected showers between 8-11 tonight! :rock:

Thanks for the timing/condition advice though.