Walk into any builder's merchant and you'll see them: rows of cartridge guns in bright plastic, pointing trowels with chipped handles, bolt-on nozzles that promise a perfect joint in half the time. Half of these tools end up in a shed drawer after one job. The other half change how you repoint a wall forever. The difference isn't price, and it certainly isn't the marketing on the box.
Choosing a mortar gun and jointing tools for repointing comes down to one question most buyers never ask: what am I actually trying to push into that joint, and how deep does it need to go? Answer that honestly and the tool list shortens dramatically. Get it wrong and you'll spend a weekend fighting a blocked nozzle while your mortar sets in the tube.
Key takeaways
- Manual cartridge guns suit shallow, regular joints; they fail on deep, ragged historic brickwork.
- Type N is the safe default for most repointing; Type S only where strength genuinely matters.
- The finishing tool matters more than the application method for a clean, weather-tight joint.
- Buy a pointing trowel and a jointing iron before you buy any gun.
- Motorised systems earn their cost on large areas, not on a garden wall.
- Consistent mortar mix beats a fancy gun every time.
What a mortar gun actually does for repointing (and where it fails)
A mortar gun is a cartridge-based applicator. You fill the tube, fit a nozzle that roughly matches your joint width, and squeeze the trigger. Mortar extrudes into the joint, you tool it back, and move on. Simple in theory.
Here's the thing: the gun doesn't compact the mortar. A pointing trowel presses material into the joint with force, pushing it against the brick faces so it bonds. A gun lays it in. On shallow joints that distinction doesn't matter much. On anything deeper than about 10mm, you'll get voids behind the face of the joint—and that's where water gets in and frost does its work.
Do mortar guns actually work?
Yes, with conditions. They work well on joints between roughly 6mm and 12mm wide, on regular brickwork needing a face-depth repair, and with a mortar stiff enough to hold shape but wet enough to flow. They work badly on deep joints, on rubble or very irregular stone, and with overly wet mixes that slump out of the nozzle.
I use one for cosmetic work and small repairs where speed matters and depth doesn't. For a proper full-depth repoint I still reach for the trowel. That's not nostalgia—it's because the gun physically can't do the compaction.
Manual vs electric mortar gun: which one earns its place
Two families exist. Manual cartridge guns (the Roughneck Ultimate, Faithfull, and countless own-brand versions sold at Screwfix and similar merchants) rely on hand squeeze. Electric and motorised systems use a powered auger or pump to drive mortar continuously from a hopper.
Manual guns cost little and are genuinely useful for patch work. Their weakness is consistency: your grip pressure varies, so the flow varies. Electric systems keep a steady rate and hold far more material, which is why crews repointing a whole elevation use them. The catch is flushing. Mortar sets in an auger tube faster than you'd believe—leave it half an hour and you're chipping it out with a screwdriver.
| Tool type | Best for | Weak point | Rough cost band |
|---|---|---|---|
| Manual cartridge gun | Patch repairs, joints 6–12mm, small areas | Grip fatigue, poor on deep joints | Low |
| Electric/motorised gun | Large elevations, sustained output | Cleaning downtime, higher outlay | High |
| Pointing trowel | Everything, especially deep or irregular joints | Slower, needs skill | Very low |
| Jointing iron / finishing tool | The final profile on every joint | None—it's compulsory | Very low |
My honest ranking: pointing trowel first, finishing iron second, gun third. The gun is a productivity add-on, not a replacement.
Should you use Type S or Type N mortar?
Type N. For most repointing, Type N is the right call—it's a medium-strength mix that flexes slightly with the wall and lets moisture escape. Type S is stronger and harder, and on soft old brick it will win the fight: the mortar stays put while the brick face spalls off around it.
Type S has its place. Modern hard-fired brick, structural elements, anywhere the masonry is genuinely strong enough to take it. If you're repointing a Victorian terrace or anything with a soft, absorbent face, Type N or a weaker lime mix is the safer route.
Matching mortar strength to the brick
The rule that saves walls: the mortar should be weaker than the masonry it sits in. That way any movement or frost damage shows up in the joint—easy to fix—rather than in the brick. Get this backwards and you'll watch faces crumble within a few winters.
- Soft historic brick: weak lime mix, Type N at most
- Modern hard brick: Type N comfortably, Type S where load demands
- Unknown brick: test a small patch first
- Never: a strong mix on a soft face because it "sets harder"
What is the best tool for repointing brickwork?
The unglamorous answer: a pointing trowel with a narrow, slightly flexible blade and a good jointing iron. The trowel presses mortar home; the iron shapes the finished joint so water sheds instead of pooling. Between them they handle every joint on the wall.
A raking tool comes before either. You need the old mortar out to a consistent depth—around twice the joint width is the usual target—and a narrow plugging chisel with a hammer or small breaker does that job far better than any gun ever will. Get the raking right and the rest follows.
The finishing tools nobody talks about
Joint profile is where a repoint lives or dies. A concave or recessed joint sheds water; a flush or proud joint catches it. A jointing iron or a shaped finishing tool produces that profile in one pass. Skip it and you've spent hours applying mortar only to leave it vulnerable.
Add a stiff brush for cleaning the brick face before the mortar fully cures, and a soft brush for the final tidy. Cheap tools, disproportionate effect.
Practical advice before you buy
If you're repointing a small area, buy the pointing trowel, jointing iron, and plugging chisel first. Add a manual mortar gun only if your joints are shallow and regular. Go electric only when the wall is long enough that the cleaning downtime and outlay make sense across the whole job.
And ignore the search noise around "mortar gun military" or unrelated hardware—you want a pointing gun, full stop. Buy from a merchant that stocks nozzles in the joint widths you actually have, and keep a spare tube so you're never cleaning set mortar out of a single gun mid-job.
The tool that repoints a wall well is rarely the one with the biggest box. It's the one that lets you press mortar into the joint and shape it before it cures—which is exactly what a trowel and iron have done for centuries, and what a gun can only help you do faster.
