Pointing brick or stone: mortar and quantities

Pointing mortar is not tile grout

We get this call a few times a month: someone has bought tile grout to point a brick or stone facing, and it has either crumbled out within a season or never matched the colour of the brick properly. Tile grout is designed for a narrow joint between two hard, fired tiles. Brick and stone pointing joints are wider, take more weather, and need a mortar with real body behind it, not a thin grout mix. Once you know that, choosing the right bag gets a lot simpler.

Grey mortar or white mortar

We stock two grouting mortars for pointing brick and stone, and the choice mostly comes down to what colour the finished joint needs to be.

Product	Colour	Typically used for
Atlas Grouting Mortar for Stone & Brick Grey 25kg	Grey	Stone facing, red or brown brick, most repointing jobs
K Dash Grouting Mortar for Bricks White 25kg	White	Cream or buff brick, feature walls, a lighter finished joint

Neither is a like-for-like swap for the other. Mixing the two on the same wall, even to stretch a short bag out, will show up as a visible colour break once the mortar has cured, so order enough of one to finish the elevation you are working on.

Match the mortar to the brick, not the other way round

A joint that clashes with the brick colour is one of the most obvious mistakes on a finished wall, and it is very hard to fix once the mortar has gone off. If you are repointing an existing wall rather than building new, take a sample brick or a photo in daylight before you order, and if you are not sure which of the two suits it, send it to us and we will tell you which one to use.

On new brick or block work, check what the rest of the job is doing. If the wall is also being tanked or waterproofed at any junction, for example where brick meets a damp proof course or a cill, that detail needs Waterproof Sealing Tape 1m bedded into a proper tanking system rather than pointing mortar, which is not a waterproof membrane on its own.

Preparing the joint before you point

Raked-out joints need to be clean and free of loose dust and old crumbling mortar before the new mix goes in, or the new pointing will not bond properly and will fail early. Flush the joint out with clean water if it is very dusty or the brick is highly absorbent, so the brick is not pulling all the moisture straight out of the fresh mortar as you work it. Check the datasheet for the exact joint depth to rake out and how long to leave between wetting and pointing, since this depends on the brick and the weather on the day, and we would rather point you to the datasheet than guess a figure here.

Working out roughly how much you need

There is no single coverage figure we can give you for pointing mortar, because it depends entirely on the joint width, the joint depth, and how much of the wall is actually joint rather than brick face. A wall with narrow, tight joints uses noticeably less material than the same wall with wide, deep joints or rough stone.

The practical way to work it out is:

• Measure the wall area you are repointing (height x length in square metres).
• Note the average joint width and depth, or take a rough estimate if you are repointing an existing wall.
• Send both figures to us rather than guessing a bag count, particularly on a full elevation, so you are not short a bag halfway through a day's pointing or left with several unused bags of a colour-matched mortar you cannot return.

A common mistake worth avoiding

Pointing a whole wall in one long session without keeping the joint depth and finish consistent from one end to the other. A wall pointed over two or three sessions, by different people, or in changing weather, often shows up later as visible bands where the joint colour or texture shifts. Mix consistent batches, work in sections you can finish in one go, and keep an eye on how the mortar is curing as you move along the wall, not just how it looks freshly applied.

For everything else on the job, from Tile Adhesives & Mortars to the Atlas Elastic Sanitary Silicone Sealant for movement joints where brick meets a window frame or cill, we can put a full list together for you.

Get your materials list sorted before you start

Send us the wall dimensions and a note or photo of the joint width and brick colour, and we will work out how much grouting mortar to order and confirm grey or white before it goes on the van. In-stock orders go out within 7 working days, and delivery is free in Ballincollig and Cork City. Collection is by appointment only.

Call 085 868 8459 or email sales@all4building.ie and we will sort the list out with you.