How to re-point brick work mortar joints on walls

broken bricks

Today we learn how to approach the task of repointing an exterior wall.

Pointing is the common British word for the mortar joints or lines of cement that surround each individual brick on the outside walls of your house.

They bind the bricks together and aid waterproofing but what happens when they need to be replaced or repaired?

Do your bricks look like they need some TLC?

Repairing and replacing mortar joins can be a time consuming, laborious and tedious task, and great skill is needed to get it right 1st time.

If an entire house needs to be repointed, this can often takes weeks or even months, however there are other ways to carry out the job quicker, so read on!

Repointing bricks

This article can also apply, in some ways, to older homes built of stone, which also have mortar joints around the blocks, which again need to be kept in good condition.

If the joints are missing then this allows water to get into the stones or bricks themselves and can saturate the brick depending on what materials they are made from so repointing bricks is something that doesn’t need to be done very often but when it does need to be done, its essential.

If this happens, the brick can soak up so much water, it starts to dissolve the bonding elements within the brick, and in the winter that water will freeze, cracking and splitting the bricks of the house. Generally the mortar around bricks is harder and more durable than the cement mortar used in laying the bricks when building the house, and the wet weather should be allowed to meet the softer mortar.

porous bricks let damp into the wall

 The effect of the weather, and erosion.

The walls of your property are designed, to a degree, to protect the structure, and the occupants from the weather outside.

This takes the form of waterproofing, weather proofing and insulation, and your walls should have at least some of this, but over time the weather erodes these qualities.

At this point (!) I must say that older brick homes can benefit from a waterproof exterior wall coating from never paint again.

The coatings come in clear silicone type or coloured and include a full wall repair before application, giving up to 20 years problem free walls!

With continuous exposure to wind, rain, frost, snow and so on,  the mortar lines holding the bricks (or stone) together on an external house wall will often start to crumble away and fall out.

A quick examination of your walls may uncover elements of this and if some joints are loose or missing, quick action is required to stop further, and more costly, damage happening, which can be seen in the next photo.

What happens when bricks erode

What happens when bricks erode

How we re-point a brick wall.

The first thing we would do is to survey the house and pin point how bad the problem is, and also which areas cause us the most concern. In most cases, pointing should be done from a portable tower or scaffolding, if not for safety, but also for ease of use, unless it is only an isolated patch, which can, in some cases, be done from a ladder.

If you are not conversant with the techniques in mortars, cement and pointing, it is best left to an expert.

Oh, and watch the WEATHER.

Don’t do this type of work in cold weather as it can crack the mortar and if rain is due, forget it, as it will wash away the work.

Equipment, tools and materials needed:

  • Chisels and screwdrivers, scrapers etc
  • Access equipment such as ladders
  • Protective and safety wear.
  • Dust sheets, buckets, trowels
  • Angle grinder (Optional)

The MORTAR to be used for the job is normally a 6:1:1 mix of builders sand/hydrated lime/cement or a 3:1 mix of sharp sand/hydrated lime.

It is a god tip to measure the amounts you use because if the mix changes, the colour of the mortar can change on different parts of the repaired wall.

We only need to mix up pointing mortar in small amounts and a bucket can be used for this.

We also replace any broken individual bricks before we start, and if its an old wall, we do try and source reclaimed and weathered bricks before we start, so the new work does not “stand out” when finished.

There is also a Machine application of pointing which a sort of “pistol” is used, coupled to a machine which pumps the flow of mortar out of the gun, however this is for very experienced personnel only and is usually used on larger areas and where a whole house needs to be repointed.

In many cases, we only need to remove and replace bad pointing but where we realise that there would be a significant colour mis-match, when using our clear wall coatings, we do sometimes take all the old joints out and replace with new. If you are considering having one of our amazing wall coatings, your local surveyor will run through the whole process with you.

Alternatives to pointing

Some people would suggest that spending a load of time on repairing mortar joints seems to be a fools’ errand if the house is to be painted or is to have the application of a never paint again wall coating on top of the bricks, so what is the alternative?

When we apply our coating system to a house that has bricks on the walls, we do replace the bad pointing, but we use a different method, which is known in the trade as bagging or bag-rubbing.

Painting brick walls

This shows a brick wall that has had the bagging treatment. The operative is now applying a primer coat to the wall.

In using our bagging system, we can apply mortar to the walls quickly and easily, whilst also filling in any voids or holes in the wall surface, AND provide a good, stable surface for the paints to be applied over. You can see in the above picture, our young lad is painting onto a wall that has been treated with bagging, which is why you can still see the bricks under the paint.

This is of course an idea way of repointing and making good the wall when after the repairs are done, a paint coating is due to be applied to the house.

It is worth noting that if you have poor condition brick walls, sooner or later the weather is going to get the better of you.

Protect your walls.

Your walls can be protected with one of our weatherproof external wall coatings which come in a variety of very nice colours and are applied by our own expert teams.

The coatings are very durable, and do not fade, crack, chip or peel. Not only that, they come with a 15 year “insurance backed” guarantee for your total peace of mind.

To find out more, send us an email, or pick up the phone, we are at (0800) 970 4928

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