Craft Quantities
Plan & Takeoffs

Materials & Quantities

Brick Movement Joint Spacing Calculator

How many vertical movement (expansion) joints a straight run of clay brickwork needs at a maximum spacing, where they fall, and the sealant they take.

  • Answers as you type
  • Every formula cited
  • Calculated in your browser
SettingsSettings for this calculationUS
Market
Imperial · sales tax
One straight run of brickwork, measured along its face from end to end.

Run each elevation on its own. An end is either a corner, where the brick turns and carries on, or a stop — an existing movement joint, a change to another cladding, or a full-height opening. Working a whole building's perimeter as one run puts joints where the corners already are and leaves the long walls short of them.

How many of the run's two ends turn a corner with no joint at the corner itself: 0, 1 or 2.

Brickwork expands toward its ends and pushes on a corner, so the first joint must sit near it: within half the spacing in the UK rule, and in the US rule within a distance that, added to the first joint's distance on the other wall, stays inside one spacing. Each corner end here is given half a spacing. Where you put a joint at the corner itself — the Brick Industry Association prefers one close beside an outside corner, and wants one at every inside corner — count that end as 0 and add the corner joint once for the building, not once per wall. The US guidance also wants a joint close to the corner on at least one of its two walls — nearer than half a bay at the usual spacing, as the second limitation gives in figures — so on a US job put that joint in on one wall, count that wall's end as 0 and add the joint once, and leave the other wall's end at 1.

The furthest apart two joints may be. The US guidance is 25 ft (7.6 m) on a plain wall; UK practice is 10 to 12 m (33 to 39 ft).

Brick Industry Association Technical Note 18A: no more than 25 ft (7.6 m) in brickwork without openings and 20 ft (6.1 m) where there are several openings. UK: about 10 to 12 m (33 to 39 ft) for clay brick, never more than 15 m (49 ft) under PD 6697, and half that for parapets, freestanding walls and lightly restrained panels. The default opens at 7.5 m, or 25 ft on an imperial page, which is within both markets' plain-wall figures. The joints come out evenly spaced at or below it.

The height each joint runs, which is the full height of the brickwork, parapet included.

A movement joint runs the full height of the brickwork it relieves — to the top of a parapet, or to the shelf angle where a tall wall is supported storey by storey. It only sets the sealant and backer rod length and does not change the joint count.

Movement joints in this run

2 movement joints

Medium confidence

This counts the joints a spacing rule needs on one straight run. The layout of a real facade starts from the places brickwork is known to crack — inside corners, offsets, openings, changes in height, backing or support — and a designer places those joints first.

Maximum spacing used
25 ft
Joint centres, as set out
24.5 ft
First joint from each corner
12.25 ft
Sealant and backer rod, one face
16 ft
Then change the inputs to see how far the answer moves.

Show calculation logic

How this was calculated

Formula source(s)

  • Brick Industry Association, Technical Note 18A, Accommodating Expansion of Brickwork (2019): vertical expansion joints at no more than 25 ft (7.6 m) in brickwork without openings and 20 ft (6.1 m) with multiple openings; the distances from a corner to the first joint in each wall sum to no more than the straight-wall spacing
  • Brick Development Association, Designing for Movement in Brickwork (2023), citing PD 6697: clay brickwork joints at approximately 10-12 m and never more than 15 m; the first joint no more than half the spacing from a corner or return; parapets and freestanding walls at twice the frequency
  • Joints = equal bays over (run + half the spacing for each end that turns a corner), at no more than the spacing each, less one. Sealant and backer rod = joints × wall height, one face.

Inputs used

Wall Run Length
49 ft
Ends That Turn a Corner
2
Maximum Joint Spacing
25 ft
Joint Height
8 ft

Intermediate steps

Maximum spacing used
25 ft
Joint centres, as set out
24.5 ft
First joint from each corner
12.25 ft
Sealant and backer rod, one face
16 ft
Final result2 movement joints

Confidence note: This counts the joints a spacing rule needs on one straight run. The layout of a real facade starts from the places brickwork is known to crack — inside corners, offsets, openings, changes in height, backing or support — and a designer places those joints first.

What this calculation does not cover

  • One straight run with even spacing. Joints that belong where the wall changes — at inside corners, offsets and setbacks, changes in wall height, backing or support, and the junction with another cladding — are not counted, and a real layout places those first and fills in to the spacing afterwards, so it normally needs more joints than this.
  • Each corner end is given half the spacing, which meets the UK rule and the US rule that the distances to the first joint on the two walls of a corner add up to no more than one spacing. It does not by itself meet the US wish for a joint within about 10 ft (3 m) of the corner on at least one wall — at any spacing above 6 m (20 ft) half a bay is further than that — so on a US job that joint is placed by hand, as the corner help explains. Worked wall by wall, a short return between two corners is given a joint of its own that its neighbours' joints may already cover.
  • The spacing is taken as typed and is the same all along the run. Nothing tightens it for openings — the US guidance drops to 20 ft (6.1 m) where there are several — or for parapets and freestanding walls, which want joints about twice as often, and the page does not check it against either market's upper limit beyond the 15 m (49 ft) the field stops at.
  • Vertical joints in clay brick only. Concrete and calcium silicate bricks shrink rather than expand and take closer joints, and concrete block has its own rule on the masonry control joint page. The horizontal joints under shelf angles, the joint width, and the filler behind the backer rod are not worked out, and the sealant length is one face at the full height with nothing added for waste.
10 ft2 m49 ft14.94 m12.25 ft3.73 m

Part of a bigger job

This trade is one line of a job takeoff. Run the whole job and every other trade comes back with it, off the same measurements.

Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.

Sources checked 2026-09-26 · v1.0.0

Regulatory standards & verification citations3
  1. Brick Industry Association, Technical Note 18A, Accommodating Expansion of Brickwork (2019): vertical expansion joints at no more than 25 ft (7.6 m) in brickwork without openings and 20 ft (6.1 m) with multiple openings; the distances from a corner to the first joint in each wall sum to no more than the straight-wall spacing
  2. Brick Development Association, Designing for Movement in Brickwork (2023), citing PD 6697: clay brickwork joints at approximately 10-12 m and never more than 15 m; the first joint no more than half the spacing from a corner or return; parapets and freestanding walls at twice the frequency
  3. Joints = equal bays over (run + half the spacing for each end that turns a corner), at no more than the spacing each, less one. Sealant and backer rod = joints × wall height, one face.
Cite this page

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Tools and safety for this job

To lay brick. Generic types, no brands, no prices.

Protection this work requires

  • Cutting or grinding concrete, masonry, screed, tile or fibre-cement board releases respirable silica: cut wet or extract at the tool, and wear a P2/N95 respirator at minimum — a nuisance dust mask does not filter it.
  • Wet cement and lime burn skin and eyes painlessly until the damage is done: waterproof gloves to EN 374, safety glasses whenever the mix can splash, and never kneel in wet mix in permeable trousers.
  • Saws, grinders and breakers run above 85 dB, where hearing damage accumulates and does not recover: defenders or plugs for every cut, not just the long ones.
  • Breakers and grinders cause permanent nerve damage: limit continuous trigger time, keep hands warm, and stop if fingers tingle or blanch.
  • Boards, blocks and bagged material cause most lasting back injuries on small sites: two people or a lifter for full sheets, and never a bag on one shoulder up a ladder.
Show the 7 tools this job needs

Essential

  • Brick trowel and jointer

  • Mixing bucket or tub

  • Spirit level

  • String line and pins

  • Tape measure

Recommended

  • Angle grinder

  • Cement mixer

Also needed as materials: cutting and diamond discs.

what each masonry tool is for, and the spec that decides which to buy where one does.

The data behind it: Production rates by operation

How to calculate brick movement joint spacing in 5 steps

  1. Wall Run LengthOne straight run of brickwork, measured along its face from end to end.
  2. Ends That Turn a CornerHow many of the run's two ends turn a corner with no joint at the corner itself: 0, 1 or 2.
  3. Maximum Joint SpacingThe furthest apart two joints may be. The US guidance is 25 ft (7.6 m) on a plain wall; UK practice is 10 to 12 m (33 to 39 ft).
  4. Joint HeightThe height each joint runs, which is the full height of the brickwork, parapet included.
  5. Movement joints in this runThe tool computes the movement joints in this run from those figures and shows the formula, its sources, and a confidence rating alongside it.

Movement joints in this run by wall run length

Page defaults, not your figures above.

Wall Run LengthMovement joints in this run (movement joints)
20 ft1
40 ft2
60 ft3
80 ft4

Frequently asked questions

Why does brick need movement joints when block needs control joints?
Because they move in opposite directions. Concrete block shrinks as it dries, so its joints are control joints — planned cracks — spaced by the wall's height as well as its length. Fired clay brick takes up moisture from the air for years after it leaves the kiln and grows, on top of expanding in the sun, so its joints are expansion joints: gaps kept free of mortar and closed with a compressible filler and sealant, spaced by length alone. Filling a brick movement joint with mortar, or carrying a block rule onto a brick veneer, gives the brick nowhere to go, and the stress comes out as cracks at the corners and openings.
Which spacing should I use?
In the US, the Brick Industry Association's Technical Note 18A gives no more than 25 ft (7.6 m) on brickwork without openings and 20 ft (6.1 m) where there are several openings. In the UK, clay brickwork is normally jointed at about 10 to 12 m (33 to 39 ft), never more than 15 m (49 ft) under PD 6697, and at half that on parapets and freestanding walls. Darker bricks on south-facing elevations move more, and the brick maker's own figure governs where it is tighter. The default opens at 7.5 m, or 25 ft on an imperial page, which is within both markets' plain-wall figures.
How wide should the joint be?
Wide enough that the sealant never has to stretch or squeeze beyond its rating. The US guidance sizes it like a mortar joint, commonly 3/8 to 1/2 in (10 to 13 mm), and its worked example gets about 23 ft (7.06 m) of spacing from a 1/2 in (13 mm) joint with a sealant that takes 50 percent movement. The UK rule of thumb is a joint in millimetres about 30 percent more than the spacing in metres, so 16 mm for joints at 12 m. The page counts joints; it does not size them.
Where do the joints actually go?
Start from the places brick is known to crack, not from one end of the wall with a tape. Put joints at every inside corner, at offsets, where the wall changes height, backing or support, and where it meets another material; then put one near each outside corner — the US guidance prefers within 2 ft (600 mm) of it, where a mason can reach round — and only then fill in to the spacing between them. The count here is that last step on one straight run, spread evenly, and a joint can always move closer to a feature — never further than the spacing from the next one.
Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — a confirmed fix gets a permanent check of its own, so the same mistake cannot come back.