Repairing your brick chimney: Part 3. Repointing

What do you do when pointing in brickwork is loose or eroded? Using our Old House Project as an example, we cover what to look for, which tools to use, getting the surface ready, pointing with lime mortar and after care.
Other videos in the series:
1. Introduction: • Repairing your brick c...
2. Flaunching and mortar fillets: • Repairing your brick c...
4. Repair and replacement of bricks: • Repairing your brick c...
For further information on this topic, download our Technical Advice Note on fireplaces, flues and chimneys: www.spab.org.u...
Have a question about an old building? Phone our free advice line on 020 7456 0916, Monday-Friday 9.30am-12.30pm or visit our website for FAQs on caring for historic buildings: www.spab.org.u...
With special thanks to Lynn Mathias.
Filmed at our Old House Project St Andrew's in Boxley, Kent by
‪@photography.tuition‬
Music: Ed Cook Sound

[@seanhealyful]

Really enjoyed this series. By far the best I've found. Thanks. Regarding the start to stiffen when in the bucket 3:16 maybe suggest covering the mix with a lazy damp rag/hessian or some plastic.

[@spab1877]

Really glad you enjoyed the videos. Yes it is a good idea in warm or windy weather conditions to cover the mortar in the bucket with wet hessian or plastic to prevent it drying out too quickly.

[@stefaneekenulv419]

A real master at work. Love it!

[@spab1877]

Absolutely! Lynn is very talented.

[@thepurpletortoise5794]

Excellent video, really well explained

[@spab1877]

Thank you for watching!

[@gemspotting6252]

Superb set of vids

[@spab1877]

Thank you!

[@chris1.2]

spoke to a bricklayer in the family who's been working 30yrs + in the trade for a company and asked about lime rather than sand and cement. He said only once has he had to use lime and that was on a listed building. Logic tells me, as long as the brick face is exposed and the building uses cement when built then using lime makes no difference because immediately behind it is cement...it doesn't make sense to use lime unless the brick was laid using lime?

[@gergemall]

Thank you

[@jameshardy6277]

I've got a 1975 build. Can I use a sand & cement mix to repoint the chimney brickwork? A Lime mix is for much older builds, is that correct?

[@thepurpletortoise5794]

May I ask why you left the gaps in the pointing on the bricks lower down on the stack? Or was it just to demonstrated how to do a small patch?

[@user-cn1em2qx6f]

would you say a ratio of 3:1. sharp sand and 3.5nhl is right for re laying any damaged bricks in a house in the west midlands birmingham. i was told the ratio depends on the climate

[@spab1877]

Hi there! It's difficult to suggest mortar mixes without knowing the location on the property (ie. chimney/wall etc..) and brick type. It could be that a 2:1 course/sharp sand and NHL 2 would be more adequate.

[@towerdave4836]

3:1 is what I used for a property exposed to coastal north westerlies where the facing was of beach cobbles, a la Norfolk/Suffolk. These are much harder than brick of course. Some of the work was done nearly 20 years ago and has shown zero cracking or shrinkage. I put that down to making a mix that was only just wet enough to make it workable, applying and packing it tight in the joints, by had rather than trowel. NHL 2 may be OK but that really depends upon the type of brick and how exposed the face is to severe weather on a regular basis.

[@kierenboimufc5940]

Good job save the brickwork from that nasty cement mortar pointing does more damage than good l. East away at the lime mortar doesnt it ?

[@spab1877]

Thank you!

[@ivanhoe6366]

The pigeons will enjoy looking at that.

[@spencergillis5679]

Why the hessian?

[@spab1877]

Good question! The hessian, sprayed with water to keep it damp, stops the mortar drying out too quickly in warm, windy weather. Lime mortars need time to carbonate or harden.

[@richardgrimbleby7853]

Chimneys 9 inch not 4

[@spab1877]

Hi Richard, this particular chimney is just one brick deep which is 4 inches

[@richardgrimbleby7853]

@@spab1877 oh okay buddy that's a little unusual tho

[@anthonymclean9743]

​@@richardgrimbleby7853 Don't know what chimneys you've worked on but they are always single brick i.e 4 inch.

[@yorkshiresfinest6102]

​@@anthonymclean9743 no they aren't loads of chimneys are double brick

[@aaronfagerstrom34]

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