Your brickwork probably needs re-pointing if the mortar between the bricks is crumbling, has worn back from the face of the wall, is cracked or missing in places, or if damp is getting in through the joints. Re-pointing means raking out the worn mortar and replacing it with fresh mortar that suits the wall. Doing it in good time keeps water out and protects the bricks themselves, which are much harder to repair than the joints around them.
Mortar is meant to be the softer part of a wall. It takes the weathering so the bricks do not have to, and it wears away slowly over the years. That makes re-pointing normal maintenance on any brick building rather than a sign that something has gone badly wrong. Here are seven things to look for.
The seven signs
1. Mortar that crumbles when you scrape it
Run a key or a small screwdriver along a joint. Sound mortar feels firm. If it turns to sand or comes away in crumbs with very little pressure, it has lost its strength. Older lime mortar is naturally softer than modern cement mortar, so compare a few areas of the wall, including a sheltered spot, before drawing conclusions.
2. Joints that have worn back from the face of the bricks
Look along the wall at an angle. Where the mortar has eroded and the edges of the bricks stand proud, rain settles on those little ledges and works its way into the wall. Some walls are built with a deliberately recessed joint, so what you are looking for is joints that are deeper or more uneven than the rest.
3. Gaps, holes and missing mortar
Patches where the mortar has fallen out, or holes you could push a finger into, let water straight into the wall. They tend to show up first on the most exposed brickwork, such as chimney stacks and freestanding garden walls.
4. Cracks in the mortar
Fine cracks along a single joint are often just weathering. Cracks that step diagonally through several rows of bricks, run through the bricks themselves, or are wider at one end than the other are different, because they can be a sign that the wall has moved. On the clay soils found in parts of Kent, which shrink in dry spells and swell again when wet, ground movement is a known cause of cracking like this.
If you see cracks of that kind, have them looked at by a surveyor or structural engineer before anyone re-points over them. Fresh mortar will hide a crack, but it will not fix whatever caused it.
5. Damp patches inside, or a wall that stays wet
A damp patch on an inside wall after rain, or an outside wall that stays dark long after the rest has dried, can point to worn joints letting water in. Older houses with solid walls, rather than cavity walls, are more exposed to this, as are walls facing the prevailing wind and rain, which in most of the UK comes from the south west.
Damp has plenty of other causes, so rule out the simple ones first. A blocked or leaking gutter or downpipe above the patch is a common culprit, and the guide on how often gutters should be cleaned covers what to look for.
6. Bricks that are flaking or crumbling
When the faces of bricks start to flake away, it is often a sign that water is getting into them and freezing. A common culprit is past re-pointing with a hard cement mortar on an older wall of softer bricks. Hard mortar does not let the wall dry out through the joints the way soft mortar does, so the moisture and frost attack the bricks instead.
If you see crumbling bricks next to hard, grey, smooth looking joints, the wall needs a different approach next time, not more of the same.
7. Plants, moss and loose grit
Moss, weeds and seedlings growing out of the joints show that the mortar is soft and holding water, and their roots will open the joints further. A scattering of sand or mortar crumbs along the foot of a wall or on a window sill is another clue that the joints above are breaking down.
What good re-pointing involves
If you are weighing up brick re-pointing, it helps to know what a careful job looks like. In general it involves:
- Raking out the old mortar to a consistent depth, without chipping the edges of the bricks.
- Brushing out the dust and lightly dampening the joints, so the bricks do not draw the water out of the new mortar too quickly.
- Pressing new mortar firmly into the joints, building it up in layers where they are deep.
- Finishing the joints to a profile that matches the rest of the wall.
- Protecting the fresh work from frost, heavy rain and strong sun while it cures.
The mortar matters as much as the workmanship. It should match the existing joints in colour and texture so the repair blends in, and in strength so it suits the bricks. Older homes, particularly Victorian and earlier, were usually built with lime mortar and are generally best re-pointed with lime rather than a hard cement mix. Tunbridge Wells and the surrounding villages have plenty of older homes, so it is a question worth asking.
If your home is a listed building, speak to your local council before any re-pointing, because work that changes its character can need consent.
Can you do it yourself?
Re-pointing a few joints on a low garden wall is a reasonable job for a careful DIYer. A whole wall of the house is a different matter. Raking out without damaging the bricks, keeping the mortar consistent and getting a neat finish all take practice, and poor re-pointing is very visible. Chimney stacks and upper walls also mean working at height, which needs proper access equipment and is a job for a professional.
Questions to ask any tradesperson
- What mortar will you use, and does it suit the age of the house and the bricks?
- How will you rake out the joints without damaging the brick edges?
- Can you match the colour and the joint finish, and will you try a small test area first?
- How will the new work be protected from frost, rain and strong sun?
- Is there an underlying cause, such as a leaking gutter or downpipe, that should be put right first?
Getting a quote in Kent
Meridian Maintenance carries out brick re-pointing and mortar repairs for homes across Kent. It is a small, family run business based in Tunbridge Wells, run by Charlie, with ten years of experience in the trade.
Quotations are free and there is no deposit to pay. Read more about brick re-pointing and mortar repairs, get in touch to ask for a quote, or call Charlie on 07742 413224.
