Pointing depth - too shallow?

[RossH]

OH B**GER! I've, just noticed Tony has recommended this on a concurrent post:

"Butter the flags, and then when you have them spaced as required, use a flat pointing tool or the edge of a trowel to ensure the butter mortar is well pressed down into the joint, leaving a minimum of 25mm depth for the eventual pointing or alternative jointing which you can do at the end of the job."

I didn't notice any instruction like that before and I've just laid a load of flags but I put a "generous" amount (i.e lots!) of buttering on and the joints are not 25mm deep - they vary up to less than 10mm deep. Will I have to try to remove the buttering before I point them now?

[Tony McC]

No, but it might be a good idea to add a bonding agent to the eventual pointing mortar to ensure it adheres to the shallow joints.

[RossH]

Thanks Tony,

Can you recommend a bonding agent? And can I use this with the semi-dry pointing technique?


Great site, and has helped me enormously. Can I suggest you include a comment about leaving 25mm depth for pointing in the "buttering or not" section of the how to lay patio flags.

[Tony McC]

Ronafix or SBR, but you need to be careful using it with the technique show on the main website because it will harden the mix in a very short period of time.

I'll see if Sim can advise on using Ronafix in such a situation. It might be that your best strategy would be to "paint" the empty joints with a slurry of Ronafix with cement, and then point as suggested on the main website.

[RossH]

Thanks Tony. Much appreciated. I'll wait until I see what you hear from Sim.

[simeonronacrete]

The best method for produce a strong, bonded pointing mortar which will stay in place much longer than a dry, brushed in mortar is to make up a mix as follows:

1 volume cement
3 volume medium or fine sharp sand

Instead of using just water, use a mix of half water and half Ronafix. Add enough of this to the cement and sand until it is the right workability / consistency and trowel it into the joint.

Prewetting the joint with clean water will reduce suction from the blocks themselves. Press it into the joint and finish it flush or recessed. Ideally achieve a min. width and depth of 6mm.

This is the best method, and time and care is needed. The brush in products/techniques are nowhere near as good as the method above.

The Ronafix mortar will be hard, strong, water resistant, and well bonded. The more densely compacted, the stronger it will be. Take care though not to stain the face of the brick, block, paver with the mortar - remember it is designed to stick!

At this point it's worth mentioning again what John Ruskin said - and here you can equate cost and money with time and patience....

"It's unwise to pay too much, but it is worse to pay too little.
When you pay too much, you lose a little money - that is all.
When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do.

The common law of business balance prohibits paying a little and getting a lot - it can't be done. If you deal with the lowest quote, it is well to add something for the risk you run. And if you do that, you will have enough to pay for something better."
JOHN RUSKIN (1819 - 1900)

Good point!

[Tony McC]

...or, as my Grandad used to say, "You buy cheap: you buy twice"...and he lived on Ruskin Drive!