How to Read Brick Bonds and Pointing: And Why Lime Beats Cement

The idea in one minute

A brick wall gives you two readable clues. The bond is the pattern in which the bricks are laid. The pointing is the mortar finish in the joints. Bond tells you how the wall was built and offers a hint about its age. Pointing tells you how the wall has been looked after, and whether anyone has done it harm.

This guide shows you how to read both from the pavement, and it ends with a caution that matters more than any pattern: unsuitable repointing is among the commonest causes of damage to old brick walls.^[1] It is the companion to our guide on how to date a house from the outside and leads into how to find out if your house is listed, which matters because repointing a listed building can need consent.

What you need: a phone camera, a ruler, binoculars for upper walls, a notebook, and low-angle daylight, which shows up the joints.

A note on dates. A bond is a clue, not a date. We give dates only where a source does.

Step 1: find a clean patch and read one course

Pick a stretch of unrendered, well-lit brick at eye level on the front, and look at the back or side too, because rear walls were often built differently.^[2]

Look at a single course, which is one horizontal row of bricks. Only two faces show. The long side of a brick is a stretcher; the short end is a header. Everything in the next section comes down to which faces appear in each course and how one course sits on the next.

Photograph a patch about ten courses high, then annotate the photo: H over each header, S over each stretcher along one course.

Step 2: name the bond

Five patterns cover most walls you will meet.

• English bond alternates whole courses of stretchers with whole courses of headers. Hammett calls it the oldest and strongest bond, used until Flemish bond arrived in the mid 17th century.^[3]
• Flemish bond alternates a header and a stretcher in every course, with each header centred over the stretcher below. The Nottinghamshire Historic Environment Record notes that it is difficult to lay;^[4] Hammett says it was popular in the Georgian period.^[3]
• Garden wall bonds put several stretchers between headers. The Nottinghamshire record gives the ratio as three to one,^[4] and Hammett says these bonds cut cost.^[3] The University of the West of England notes that rear walls were often built in a cheaper garden-wall bond.^[2] Wikipedia says the Flemish garden wall bond is also called Sussex bond.^[5]
• Header bond shows only the ends of bricks. Hammett says it is used for curves and high-quality work; the Nottinghamshire record adds that it does not always need a skilled bricklayer.^[3][4]
• Stretcher bond shows only long faces, each course shifted by half a brick. The Nottinghamshire record calls it weak,^[4] and Hammett says it is mainly used for cavity walls.^[3] It hints at a wall that is not solid brick, but only as a hint.

To tell them apart, count along one course: S H S H is Flemish; S S S H is a garden wall variant.

What the bond tells you about age

Treat bond as supporting evidence. Hammett’s account puts English bond first and Flemish after the mid 17th century,^[3] so a front in English bond on a house you otherwise judge Georgian deserves a second look. We have no source for how long English bond stayed in use, so treat that as a prompt to check.

Flemish bond on a front is unremarkable for a Georgian house, but it is not a date on its own. Combine the bond with windows, doors and roof using our exterior dating guide, and with the inside clues in identify the period of your house from plasterwork.

Step 3: read the pointing

Pointing is the visible mortar finish. Designing Buildings lists the usual styles: flush, recessed or raked, bucket handle (concave), struck or weather struck, rubbed, V, tuckpointing, penny roll, and strap or ribbon.^[6] It adds that a recessed joint should be set back at least 5 mm.^[6]

Tuckpointing is the showy one. Wikipedia describes it as a late 18th-century English technique that imitates rubbed brick, with a fine white fillet laid over coloured mortar.^[7] Surrey’s advisory leaflet says tuck pointing needs an experienced contractor.^[8]

Look for erosion too. The same leaflet gives about 12 mm of mortar loss as the point at which repointing is due.^[8] Colour and profile alone cannot tell you what the mortar is made of; ask a surveyor to identify it before you commission work.

Step 4: lime or cement, the caution

This is the part to read twice. The New Forest National Park Authority says lime mortar is porous and flexible, while cement is dense and traps moisture and frost.^[9] Surrey’s leaflet says the mortar should be weaker than, and at least as porous as, the wall, and that lime is usually right.^[8] Historic England states that unsuitable repointing is one of the commonest causes of damage.^[1]

The New Forest guidance is blunt: do not use cement-based mortar, and use a mix of one part lime to three of sand.^[9] The Northern Ireland note adds that fresh lime is frost-vulnerable for about three months.^[10]

For lime indoors, see lime vs gypsum plaster.

Step 5: decide whether to repoint

Often the answer is no. Historic England says comprehensive repointing is rarely needed and that sound historic mortar should be left undisturbed.^[1] The New Forest guidance says to repoint only missing or badly eroded areas.^[9]

If you do go ahead, ask for a written specification: mortar type and mix, raking depth, joint profile and aftercare. For a listed building, the New Forest guidance says listed building consent is needed for work that is not like for like. We are not giving legal advice: ask your local planning authority’s conservation officer before you start, and read how to find out if your house is listed.

What a good repointing job specifies

The raking-out depth is where the sources differ slightly. Surrey says at least 20 mm;^[8] the New Forest guidance says at least twice the joint width;^[9] the Northern Ireland note says at least 2.5 times the joint height, or 25 mm for a 10 mm joint.^[10] The New Forest guidance also says raking out should be done by hand.^[9]

The Northern Ireland note asks for a brushed finish and for the joints to be kept damp for seven days.^[10] Planning the work for the warmer months, given the three-month frost risk, is our inference.

Worked example: a Georgian-looking front

Imagine a brick house front with 10 mm joints (an illustration, not a real house).

1. Read the front. Along one course you see header, stretcher, header, stretcher, each header over the middle of a stretcher below. That is Flemish bond.
2. Read the back. Three stretchers between each header: a garden wall bond. That matches the cheaper rear walls the University of the West of England describes.^[2]
3. Read the joints. Most mortar is sound. In the lowest courses on the weather side, say it has eroded about 14 mm. That is past the 12 mm Surrey gives.^[8]
4. Choose the repair. Repoint the eroded areas only^[9] and leave the sound mortar,^[1] using lime.
5. Set the depth. For a 10 mm joint, twice the width is 20 mm, which matches Surrey’s minimum; 2.5 times the height is 25 mm. Specify 20 to 25 mm, by hand.
6. Mix. One part lime to three of sand: a batch of 2 buckets of lime and 6 of sand makes 8 buckets of mortar. The arithmetic is ours.
7. Aftercare. Keep the joints damp for 7 days and protect them from frost for about three months.^[10]

Common mistakes

• Using cement because it is stronger. For old brick, stronger is the problem.^[9][8]
• Repointing sound mortar. It removes original material and risks damage.^[1]
• Raking out by machine. The New Forest guidance says by hand.^[9]
• Using a general builder for tuckpointing. It needs an experienced contractor.^[8]
• Skipping consent on a listed building. Ask the conservation officer first.^[9]

Quick-reference table

Glossary

What to do next

If the mortar is failing, get a written specification before any work. For the age of the house see how to date a house from the outside; to find out whether it is protected, read how to find out if your house is listed. For a real restoration story, see restoring a period home in Shropshire.

Keep reading

• How to date a house from the outside
• How to find out if your house is listed
• Lime vs gypsum plaster
• Restoring a period home in Shropshire
• Georgian interiors guide

Frequently asked questions

How do I tell what brick bond my house is?

Look at one course. Long faces only is stretcher bond; ends only is header bond; whole courses alternating is English; header and stretcher alternating in each course is Flemish. Three stretchers between headers is a garden wall bond.

What is Flemish bond?

A bond in which each course alternates a header and a stretcher, with each header centred over the stretcher below. The Nottinghamshire HER notes it is difficult to lay.

What is the difference between English and Flemish bond?

English bond alternates whole courses of stretchers and headers. Flemish alternates headers and stretchers within every course. Hammett calls English the oldest and strongest.

What is garden wall bond?

A cheaper bond with several stretchers between headers, three to one according to the Nottinghamshire HER. Rear walls were often built in one.

Is stretcher bond old?

It is weak by the Nottinghamshire HER account, and Hammett says it is mainly used for cavity walls. On a house, it hints at cavity-wall building, but it is a hint, not a date.

Why not repoint old brick with cement?

The New Forest NPA says cement is dense and traps moisture and frost. Surrey says mortar should be weaker than the wall.

How deep should repointing be raked out?

Surrey says at least 20 mm; the New Forest guidance says at least twice the joint width; the Northern Ireland note says 2.5 times the joint height. For a 10 mm joint that is 20 to 25 mm.

Do I need consent to repoint a listed building?

The New Forest guidance says listed building consent is needed for work that is not like for like. This is not legal advice: ask your local planning authority's conservation officer before you start.