Repointing looks simple: rake out the old mortar, put new mortar in. In practice it is one of the easiest jobs to get wrong, and poor repointing can do more harm to a wall than leaving it alone. We regularly put right repointing done by others across Sussex, and the same mistakes come up again and again.
Whether you are planning to do it yourself or hiring someone, here is what to watch out for.
Worried about your brickwork? We will inspect it for free and tell you honestly whether it needs repointing. Request a free quote or call 07771 393494.
1. Using cement mortar on an old house
This is the most damaging mistake. Homes built before around 1920, which includes much of Lewes, Battle, Tunbridge Wells and the older parts of Brighton, were built with soft bricks and lime mortar. Lime is flexible and lets moisture escape through the joints.
Hard cement mortar traps that moisture inside the bricks instead. Over a few winters the water freezes and the faces of the bricks break away, a problem called spalling. The mortar survives and the bricks do not, which is the wrong way round.
Get it right: match the mortar to the wall. Old, soft brickwork needs a lime mortar. The mortar should always be slightly weaker than the bricks.
2. Not raking out deep enough
Skimming fresh mortar over the top of old joints is a shortcut that fails quickly. The thin new layer has nothing solid to bond to and falls out within a year or two.
Get it right: rake joints out to a depth of at least twice their height, typically 15mm to 25mm, back to sound mortar.
3. Damaging the bricks with an angle grinder
Grinders are fast, but used carelessly they widen the joints and chip the edges of the bricks. The wall then looks permanently scarred and the wider joints are more obvious once refilled.
Get it right: use a grinder only on hard cement joints, with care, and finish by hand with a plugging chisel. Soft lime joints can often be raked out entirely by hand.
4. Smearing mortar over the brick faces
Mortar spread across the face of the bricks, sometimes called buttering or bagging, looks messy and is very hard to clean off without damaging the bricks.
Get it right: fill joints with a pointing iron and keep the brick faces clean. Brush off excess once the mortar has firmed up.
5. Not wetting the joints first
Dry bricks and old mortar suck the water out of fresh mortar too fast. It does not cure properly, stays weak and can crack away from the bricks.
Get it right: brush out dust and dampen the joints before pointing, especially in warm or windy weather.
Want it done properly the first time? Our team has over 20 years of experience repointing homes across East and West Sussex. Book a free site visit or call 07771 393494.
6. Working in the wrong weather
Mortar laid in frost can freeze before it sets, and mortar laid in hot sun or strong wind dries out too fast. Both lead to weak, crumbling joints.
Get it right: avoid pointing when temperatures are close to freezing. Cover fresh work with hessian or sheeting to protect it from rain, sun and frost while it cures.
7. Choosing the wrong joint profile
Recessed joints may look smart on a modern house, but they hold water on a weather-exposed wall. That matters on the coast at Seaford and Eastbourne and on high ground around Crowborough.
Get it right: match the existing joint profile, or use a bucket handle or weatherstruck joint on exposed walls so rain runs off.
8. Not matching the colour
New mortar that is a different colour from the old leaves a patchwork effect, especially on partial repairs. Fresh mortar also dries lighter, which catches many people out.
Get it right: mix test samples with different sands and let them dry before you start. We always do this on patch repairs so the new work blends in.
9. Treating the symptom, not the cause
Mortar that has washed out under a leaking gutter or behind a cracked downpipe will wash out again if the leak is not fixed. Cracks that run diagonally through joints near windows may point to a failing lintel rather than old mortar.
Get it right: find out why the mortar has failed before repointing. Fix leaks, and get structural cracks checked.
Should you repoint it yourself?
Small areas at ground level, such as a garden wall, can be a reasonable DIY job if you take your time and use the right mortar. Whole elevations, chimney stacks and anything needing scaffolding are best left to a professional. Working at height is dangerous, and poor repointing on a large area is expensive to undo.
Get your repointing done properly
Bradford Brickwork has been repointing homes across East and West Sussex for over 20 years. We match the mortar, joint style and colour to your home, and we cover chimney repointing too. Read what our customers say on our reviews page, where we are rated 9.77/10 on Checkatrade.
Get your free quote or call 07771 393494.
FAQs
How do I know if my wall was repointed badly? Look for mortar smeared over the bricks, joints that sound hollow when tapped, cracked or loose new mortar, or bricks crumbling next to hard grey joints.
Can bad repointing be fixed? Yes. The poor mortar is carefully raked out and the wall is repointed with the correct mix. Damaged bricks may need replacing.
What mortar mix should I use for repointing? It depends on the bricks. Modern brick usually suits a 1:5 or 1:6 cement, lime and sand mix. Older soft brick needs a natural hydraulic lime mortar.
How long should repointing last? Done properly, repointing should last 50 years or more.
