BRICK WALL CONSTRUCTION

BRICKWORK MANUAL

The Brickwork Manual aims to assist builders who work with clay bricks. With a rich history spanning back to 8000 BC, the basic requirements for good brickwork is well understood while the industry is continually evolving to incorporate new products and processes. This manual serves to reinforce best practice. It is important to appreciate best practise and the minimum requirements by building standards are not necessarily the same thing.

The Brickwork manual can be downloaded from here:

We also recommend that all builders, brickies and customers obtain a copy of the "Construction Guidelines For Clay Masonry Manual" to ensure brickwork construction is done according to all guidelines and best practises. This will prevent unnecessary problems and costs once walls have been laid.

GETTING THE MOST FROM YOUR BRICK

Nothing is more important than good brickwork, choosing the best brick needs to be followed up by a thorough understanding of how to get the best from your chosen brick and this needs to be communicated to your architect, builder and brickie.

Below we list the key areas that must be adhered to ensure brickwork meets your expectations and brickwork must be done in strict accordance with best practise as outlined by "Construction Guidelines For Clay Masonry Manual"

BRICK TYPES

Handmade Bricks vs. Conventional Extruded Bricks

Handmade bricks are still just bricks, they have to meet all the same standards that conventional mass produced bricks do. The main difference between a handmade brick and a conventional mass produced extruded brick is character. Handmade bricks have an individuality that can not be achieved via mass production. All our bricks exceed Australian standard for unconfined compressive strength as per AS/NZS 4455 along with European Standard BS EN771-1:2011 with a compressive strength >10.5 MPa. All our bricks are classified as General Purpose building bricks.

Types of Handmade Bricks

Sandstock Bricks

This is often a misunderstood term and is unfortunately applied to bricks that are not sandstocks. Sandstock bricks are produced using the sandstruck method in which clay is hand pressed into a mould dusted with fine sand. Sandstock bricks have a regular rectangular "brick shape" but have highly textured elephant skin creasing and slightly ragged/chipped edges, this is their defining characteristic. Sandstock bricks are a solid brick with a nominal size of 230mm x 70mm x 110mm or 215mm x 65mm x 105mm.

Waterstruck Bricks

Unlike sandstocks, waterstruck bricks have smoother textures, this is achieved by using wetter clay and the moulds are lined with water. Waterstruck moulding is sometimes referred to as "slop" moulding. Bricks produced using this method are often slightly misshapen with deformed edges, this along with their smoother texture is their defining characteristic. Waterstruck bricks are a very popular European style, are a solid brick with a nominal size of 215mm x 65mm x 105mm.

Are handmade bricks for you?

We would like to think that the answer is a resounding yes. But simply, if you are after a brick with character and individuality in colour and texture, then handmade bricks are for you. Handmade bricks will also have a natural variation in size between bricks, typically a maximum variation of +/- 5mm can be expected from the quoted nominal size. If you are after a highly uniform looking brick in terms of colour and texture, then handmade bricks may not be for you. All handmade bricks will have a certain aged appearance and will be perfectly imperfect.

Pressed Bricks

Pressed bricks are machine pressed into single moulds, as the pressing force is greater than hand pressed bricks, pressed bricks tend to have less texture on the face of the brick and a more regular shape.

Clinker Bricks

Clinker are defined by their hardness and are partly machine made but in our case are dry tumbled to produce a hard brick with rough rounded edges. These bricks have internal perforations with a nominal size of 215mm x 65mm x 105mm.

Reclaimed Bricks

While most of the bricks we offer a new handmade or pressed bricks, we do offer a limited range of reclaimed bricks (Cottage Reds, Prague Greys, Jerusalem Whites, Missionary Greys, Sculptured Reds, Wellington Multis and Reclaimed Fire Bricks). Reclaimed bricks are still just bricks but will have an aged and tumbled appearance and will have amazing individuality. Residual mortar on reclaimed bricks is normal; and part of the charm of reclaimed bricks, but please be aware that the amount of residual mortar is entirely random. Demolition dirt will also be present on reclaimed bricks, this is normal and is washed off during the brick cleaning stage using standard pressure washing techniques.

THE BRICKIE

Nothing is more important to good brick work than a good brickie. It's a common stereotype that brickies are unskilled labourers, however this is not the case at all, brick layers are highly skilled tradespeople, but like any industry, there are good ones and also some not as skilled. No matter how nice the bricks are, an unskilled brickie (this is rare) or a brickie doing the brickwork in a hurry (way too common) can ruin the final outcome of the project. Choosing the cheapest brickie (this virtually guarantees a rushed job) is rarely the best approach. Choose your brickie carefully, make sure your brickie has lots of experience laying face bricks. In many cases a brickie who normally lays bricks intended to be rendered may not be the best brickie for laying face bricks.

Brick Blending

The composition of the raw materials, as well as the firing process of the brick will result in colour and dimensional variations from brick to brick, from pallet to pallet and batch to batch. This variation is inherent in the process of handmade bricks and is a key component to the appeal of handmade bricks.

To ensure that colour and dimensional variations are dealt with correctly, we advise that the bricks are blended during laying and that bricks are ordered in a single batch. The best method to do this is to select bricks from numerous open packs (e.g. 4 to 6 but the more the better). This will ensure a beautiful finished product. With all our bricks, there are multiple usable faces, further blending can be achieved by the sensible selection of which face to use. Tinted bricks (Pale Sanded Grey, Roman Pale Sanded Grey, Ironbark Grey) in particular may not have 4 usable faces, sensible selection of which face to use is required.

It's important to remember many parts of a house can be easily modified or replaced at a future time......internal paint colours can be refreshed, furniture and fittings can also be changed/modernised comparatively easily over time. However, your external facade can not be easily changed, so getting it right at the start is important. Money spent on your bricks and your brickie is a long term investment in your home.

STORAGE OF BRICKS

Our bricks are delivered wrapped and strapped to pallets and should be left on the pallets until needed and kept wrapped, but cut air vents in the plastic wrapping to allow the bricks to breath and prevent the growth of mould. When bricks are stacked ready for use they should not (i.e never) be placed in direct contact with the ground, this promotes infiltration of ground water into the bricks and can cause staining and contribute to excessive efflorescence.

MORTAR CHOICE

Choosing a mortar colour is really important. Broadly mortar colours can be divided into four broad types: dark grey/black, grey, yellow (buttery) and white (creamy).

Yellow/Buttery Mortar

Yellow or a buttery colour is a common colour used (particularly with red bricks) and is produced by using a yellow brick sand combined with an off white cement, this will produce a buttery coloured mortar, the addition of hydrated lime will lighten this colour further.

Creamy White

For a creamy white mortar you use a white brick sand with a white cement.

Grey

This is the most simplest mortar colour to achieve and is just a simple mix of grey cement and white (best) or yellow brick sand. Standard grey mortar can also be purchased premixed in most hardware stores.

Dark Grey to Black

For dark grey to black mortars a black oxide must be added to the standard grey cement. Black oxides can be purchased readily at most hardware stores. Please be aware that dark mortars:

Can fade over time to grey.
Can leach onto brick work (red to black stains), this is most common during the first months of construction and can be a particular problem with light coloured brickwork.

Both sand, cements and coloured oxides are readily available from hardware stores (e.g. Bunnings). To stress the point, yellow and white mortar can not be produced with the standard grey cement and for a true white mortar you must use a pure white cement and white brick sand. Links to examples of these products can be found below:

We are happy to supply the correct cement for you.....just ask.

Please note that with white, and off white mortars, the colour will also be affected by the local brick sand available to you.

Mixing Mortar

Mortar should be batched, this means volumes of sand, cement, lime, oxide and water should be carefully measured, generally using buckets of a consistent volume. Estimating the mix ratio of the mortar based on shovels is a clear sign of poor skills and/or workmanship and will result in inconsistent mortar colour and strength. It is a great idea to make small batches of mortar to trial colours. Please be aware the true colour of a mortar is not apparent until it is 100% dry.

IMPORTANT

* As with all building work, advice should be sought from qualified professionals if you are unsure of any aspect of brick laying, cladding or paving.

DEBUNKING A MYTH: EFFLORESCENCE

Efflorescence describes crystalline salt deposits on brick, concrete, and other masonry surfaces. When we say salt we do not mean table salt (NaCl) but rather calcium sulfates and calcium hydroxides. It most often appears initially as a white rim around the brick during laying. Despite brickies constantly telling people the salt is coming from the brick, the truth is that the source of efflorescence is not from the brick but from the mortar. You can test this yourself, get a new dry brick from the pallet, soak it in water and let it dry, we guarantee you will never see efflorescence coming from the brick under these circumstances.

The cause and source of efflorescence is the sand, cement and lime in the mortar. During laying, the wet mortar which contains the soluble salts is absorbed by the dry brick, this water evaporates at the brick surface leaving behind a residue of the soluble salts.

While efflorescence can be unsightly it is harmless and will go away naturally over time. This process can be speed up by washing with a hose, but wait until the brick work is completely dry so that the evaporation process that carries the salts from the mortar into the brick is complete. Limiting efflorescence is the best approach and can be achieved by the use of several techniques including:

Making sure the mortar is not made too wet;
Making sure mortar is batched appropriately and ensuring the correct amount of cement and lime is used, excess cement and lime will promote efflorescence;
The use of efflorescence blocking additives such as Efflock. Highly recommended when core filling pillars and with all reclamation style bricks.

BRICK CLEANING & BRICK CARE

In most cases (not all...see section for grey bricks, tinted bricks and reclamation style bricks) cleaning of brick work can be achieved using standard techniques. Brick cleaning is no substitute to clean brick work done by a professional bricklayer competent in laying face bricks. Cleaning as you go is the best method for ensuring good brickwork. Mortar dag and smears are best cleaned when soft and workable (i.e not when still wet as this will just smear the mortar on the brick face) and when working on upper levels care should be taken to clean the brickwork below the scaffold as well as the active work area. Cleaning of brick work should never be left to the last thing to do on a build. The appearance of brickwork can be spoilt by bad cleaning techniques or by the use of the wrong cleaning agent or technique.

We recommend that all builders and customers obtain a copy of the ThinkBrick cleaning manual to ensure brick cleaners follow all the guidelines. This will prevent unnecessary problems and costs once walls have been laid.

These recommendations are made in accordance with the Think Brick Australia Brick Cleaning Manual.

Guidelines for high pressure cleaning:

Allow the mortar to harden for at least 3 days, but not longer than 3 weeks.
Protect adjacent materials (e.g. window frames etc.)
Saturate brickwork with clean water and never let the wall dry out during cleaning.
Test a small unseen section prior to full-scale cleaning.
Keep pressure low - maximum 7000kPa (approximately 1000psi).
Use a wide fan spray nozzle.
Keep the nozzle a minimum of 1.0m from the wall.
Keep the nozzle moving constantly to avoid surface abrasion in one spot.
Do not use a turbo jet head or concentrated stream of high pressure water, as damage to the brick surface and mortar is likely to occur, only use a diffuse spray.
As with all building work, advice should be sought from qualified professionals if you are unsure of any aspect of brick cleaning.

IMPORTANT:

High pressure washing should only be used to remove the thin film of residual cement that may be present. These techniques are not meant to be used to clean off mortar dags. Attempts to clean off mortar dags via high pressure washing typically results in damage to the brickwork. Mortar dags should be cleaned off via dry brushing during brick laying, best done when the dag is not still wet (this will prevent smearing the mortar dag) but still soft and workable, under these conditions the dag can be simply brushed off.

High pressure washing can not be done on reclamation style bricks!

High pressure washing can not be done on tinted bricks!

ACID WASHING

Experience shows that acid-washing brickwork can cause various types of damage. All efforts should be taken to ensure that building is performed clean enough not to need acid washing (in the past, brickwork was never acid washed!). With acid washing, various forms of damage can arise, such as greyish mortar bloom on the bricks as a result of premature acid washing, degradation of the joint surfaces and changes in the colour of bricks and joints through staining. Mortar residues are not always an eyesore (especially on light coloured brickwork) and will often wash off with time.

Acid washing can not be done on reclamation style bricks!

(e.g. Reclamation Heritage Reds)

Acid washing can not be done on tinted bricks!

(e.g. Weathered Parliament, Vintage Stock, Pale Sanded Greys, Roman Pale Sanded Greys)

Acid washing should be done with within 7 days of bricks being laid. Allowing cement to fully set before cleaning can lead to unintended damage due to the aggressive cleaning required.

Guidelines for acid washing if absolutely required:

Important: Hydrochloric acid is a hazardous material. All guidelines by the manufacturer must be adhered to. If this method is used incorrectly, it can result in unsightly staining that is more difficult to remove. In particular, care should be taken to treat any vanadium stains prior to cleaning. Acid washing is best done by trained professionals.

Test a small unseen section prior to full-scale cleaning.
Protect adjacent materials (e.g. window frames etc.)
Saturate the area of brickwork to be cleaned and all adjacent areas below with water.
Use the correct ratio of hydrochloric acid and water - 1 part hydrochloric acid to 20 parts water.

Warning: Under no circumstances should more than 1 part hydrochloric acid to 10 parts water be used.

Always begin at the highest point and work down the wall.
Only clean small areas at a time - e.g. one square metre - so as to allow adequate time to wash off the cleaning solution.
Allow solution to remain on wall for 3-6 minutes (no scrubbing).
Rinse thoroughly, making sure all cleaning solution has been removed.
All light coloured brickwork & internal exposed brickwork washed with acid should be neutralised.
As with all building work, advice should be sought from qualified professionals if you are unsure of any aspect of brick cleaning.

IMPORTANT:

Acid washing should only be used to remove the thin film of residual cement that may be present. These techniques are not meant to be used to clean off mortar dags. Attempts to clean off mortar dags via acid washing (or high pressure washing) typically results in damage to the brickwork. Mortar dags should be cleaned off via dry brushing during brick laying.

Special Cleaning Requirements for Reclamation Styles
Our reclamation styles, which can be identified by the white scumming on the brick surface, should not be wet sponged, acid washed or high pressure cleaned. During laying, the excess mortar should be cut off with a trowel and the brickwork should be dry brushed (once mortar has had time to partially dry, do not dry brush when mortar is still very wet). The bricks from the pallets are left intentionally dusty, this allows mortar dags and smears on the work face to be removed easily by dry brushing.

Do not sponge the joints of the brickwork, otherwise it may create permanent stains.

We also advise that with our reclamation styles, the mortar colour is matched closely to the colour of the white scumming (i.e. white to off white mortar).

With our reclamation styles we strongly recommend the use of efflorescence blocking additives such as Efflock.

If these instructions are followed the result will be a beautiful reclamation finish as seen here.

Special Cleaning Requirements for Non-Through Colour Tinted Grey Bricks (Weathered Greys, Pale Sanded Grey, Roman Pale Sanded Grey, Vintage Stock, Weathered Parliament)

These bricks are artificially weathered during production generating an exterior grey veneer on the brick surface. During laying, the excess mortar should be cut off with a trowel and dry brushed (once mortar has had time to partially dry, do not dry brush when mortar is still very wet). Once this process is complete, chips can be recoloured using our supplied brick pigment. Please note weathered grey bricks are non-through colour bricks (they are paired with an underlying ivory sandstone colour), weathered grey bricks are meant to naturally weather into their local environment over time (typically lighten but can also darken) similar to natural timbers and sandstone. If you wish to limit this process you may wish to seal these bricks, this should be done concurrently with laying (e.g. Brick and Render Sealer). These bricks should not be acid washed or high pressure washed*. Please note if you are after bricks with a permanent and consistent grey colour, you should be choosing our reclamation greys or reduction grey bricks, not weathered grey bricks.

Do not sponge the joints of the brickwork, otherwise it may create permanent stains.

* High pressure cleaning can be used if a really pale ivory/grey exterior is desired. High pressure cleaning will allow more of the underlying ivory clays to show through.

Special Note on Light Coloured and Tinted/Weathered Grey Bricks - Vanadium Staining:

The clays used to make light coloured bricks (e.g. ivory bricks, off white bricks, cream bricks, grey bricks) often contain Vanadium. On occasion yellow/green/red-brown staining may appear on light coloured clay bricks. This is known as vanadium staining. This staining is a natural by-product of clay products and is not harmful. Typically the stain will appear if excessive acid is used in the cleaning process or if the bricks get excessively wet (during construction (i.e. before flashings/copings/sills have been installed), brickwork should be protected from stormwater through the use of tarps and other coverings). Over time they will disappear through natural means if exposed to the elements.

These stains can be removed by using a solution of oxalic acid and water and must be followed by a neutralising wash, such as a sodium bicarbonate solution, to avoid serious secondary staining down the track. It is important to always follow the safety instructions and warnings on any labels of chemicals used.

It is important to understand and accept that vanadium staining is a natural process of clay products and is most obvious in light coloured bricks. Sealing of bricks can help minimise vanadium staining but if you are concerned about this process we would advise against the use of light coloured bricks.

Please also be aware that light coloured bricks which are based on natural ivory coloured clays will show pinks through to pale reds due to iron within the clay.

Special Note on Sandstock Bricks:

Sandstock bricks when taken straight from the pallets are covered by a loose sandy veneer. This is an intentional feature as it allows mortar dags to be easily brushed off during laying and helps to limit the need for aggressive brick cleaning techniques. This loose sandy veneer will come off with high pressure washing or naturally over time.

Sponging of Brickwork

We never advise the wet or dry sponging of brickwork during laying. Sponging of textured bricks smears a thin film of cement over the brick face, we only ever recommend dry brushing of brickwork during laying.

Finishing Off Joints:

The shaping of the mortar within the joints is an important element to the final finished look. Joint types include:

Flush
Weather Struck
Cut and Struck
Rolled
Raked

As a rule of thumb joints should be done in a manner to facilitate water to flow off the brick work (those highlighted above are ideal for the shedding of water) . As a general rule we do not recommend raked joints as it allows water to pool within the joint, promotes dust and dirt to collect within the raked joint and provides an easy place for insects to create nests (e.g wasp nests), quite simply, raked joints do not represent good brickwork.

Regardless of what joint type you choose, the "shaping" of the joint should be done when the mortar is still "workable" but not too wet. Shaping of joints when the mortar is too wet will result in messy unclean brick work which can never be cleaned to a satisfactory standard. Shaping of joints when the mortar is too wet is a clear sign of a rushed job.

Reclaimed Bricks

We currently offer a number of reclaimed bricks, these include Cottage Reds, Prague Greys, Missionary Greys, Sculptured Reds, Wellington Multis and Original Fire Bricks. These should not be confused with our new handmade bricks.

Reclaimed bricks are just bricks that have been used previously and have be salvaged during building demolition, for this reason they offer both aesthetic appeal and practical benefits, making them a compelling option for those looking to build sustainably. According to ‘Emissions Estimate Technique Manual for Bricks, Ceramics & Clay Product Manufacturing’ commissioned by Environment Australia there is 1.65 kg of carbon dioxide emitted for each tonne of bricks produced from a gas-fired kiln each year. Every time you use a reclaimed brick you are helping to reduce the emission of CO2 into the atmosphere.
Reclaimed bricks are still just bricks and can be used for both the construction of brick walls and for paving. All our reclaimed bricks have a P5 slip rating.
Residual mortar on reclaimed bricks is normal; and part of the charm of reclaimed bricks, but please be aware that the amount of residual mortar is entirely random.
Reclaimed bricks will have an aged and tumbled appearance, however, the intensity of this effect is random. Reclaimed bricks will be perfectly imperfect and will include cracks, chips, an aged/weathering patina, residual mortar and in some cases residual paint which they have acquired from their prior use.
Reclaimed bricks may contain residual calcium sulfate which appears as a white powdery residue on the brick surface. This residue is harmless and will wash away over time.
Loose demolition dirt/lime will also be present on reclaimed bricks, this is normal and is washed off during the brick cleaning stage using standard washing techniques. All pictures seen on our website of our reclaimed bricks have been washed, washing is done during brick wall construction, our reclaimed bricks do not come pre-washed.
Due to reclaimed bricks coming from different buildings, blending from multiple pallets when building is important for managing variations in colour, residual mortar and patina intensity.
All our reclaimed bricks can be cleaned via low or high pressure washing techniques (see our guide on pressure washing above). Acid washing can also be done but please be aware acid washing will remove some of the residual/original mortar on the bricks and much of the original lime. As this residual mortar is for many a large part of the appeal of using recycled bricks, we typically advise against acid washing for this reason, however, if you want them with less mortar....go for it.
If you are concerned about using reclaimed bricks, you may wish to use our "reclamation style" bricks, which are new bricks made to look like reclaimed bricks.

LAYING CLEAN

This is the most important piece of information on this page, laying clean prevents many of the common issues that arise during brick work construction. Relying on aggressive cleaning techniques is the number one cause of damage to brick work.

When we talk about laying clean the picture here is a great example. These bricks have NOT been pressure washed or acid washed, just dry brushed using a clean as you go approach......notice that there are no mortar dags or cement smears on the brickwork. This is the quality of brickwork you should expect and what can be achieved by good brick layers.

EXPOSURE TO THE ELEMENTS

Walls Under Construction

In line with Think Brick Australia guidelines, covering of walls during construction is critical, failure to cover walls during wet weather allows for excessive water penetration, stormwater interaction with fresh mortar joints will result in the leaching of iron from the bricks, this iron will oxidise on the surface of brickwork causing unsightly iron rust stains that can be difficult to remove. Furthermore, water penetration can lead to other forms of damage including excessive shrinkage, efflorescence and staining.

Finished Walls

All bricks can and will be affected by exposure to the elements over time which can affect their appearance. For example;

Bricks can darken due to local pollution;
Bricks experiencing excessive wetting can stain over time;
Weathered/tinted bricks will fade/lighten over time (this is the desired result of weathered grey bricks, they are meant to naturally weather into their local environment in a manner analogous to natural timbers).
Ground water can cause staining;
UV exposure can cause bricks to fade.

These are all natural processes but in some cases can be limited or sometimes avoided by specific building and/or cleaning techniques. However, as bricks are made from porous natural materials, all brickwork exposed to the environment are what we deem to be "living" products. In a manner analogous to timbers and stone, all bricks will change due to environmental exposure. For obvious reasons, light coloured bricks are more likely to show the effects of environmental exposure. To limit changes due to environmental factors, building/masonry design should be best practise (this is often means going above and beyond minimum building standards) to minimise exposure to the elements, particularly stormwater. Masonry design must prioritise function first and form second. As stormwater is one of the most common environmental factors that can affect a bricks appearance, Think Brick Australia (and us) advise that stormwater should be shed so as to clear the masonry below, specifically:

Flashings, copings and sills should project at least 10 mm beyond the wall face at the underside of the sill or coping.
Flashings, sills and copings should be angled to properly shed water away from brickwork. This is really important, stormwater is dirty water, you do not want this waterfalling down your brick work and staining it. Stormwater is meant to go into your gutters, not down your brick work.
Where downpipes have not been installed water from the roof and guttering should be diverted away from brickwork.
Building standards require damp-proof courses and flashings to be provided/designed to prevent moisture from moving upward or downward through the masonry. Once installed, it is critical to ensure that other building elements and landscaping do not allow moisture to bypass damp-proof courses and flashings.
The materials for damp-proof courses, copings, flashings and weatherings must comply with AS/NZS 2904.
Sealing of bricks in particular can help prevent staining and UV damage. Light coloured and tinted bricks should always be sealed immediately after laying (e.g. concurrently with laying) to help prevent staining. Please remember light coloured brick work is like any light colour, it is more prone to show stains (e.g. a white shirt is more likely to show stains than a black shirt). Sealing light coloured brick work will not totally prevent stains but will help with cleaning them if required. Common stains to be aware of are oils from overhanging trees, bird poo and stains caused during construction (e.g. mud).

As stormwater is naturally acidic (more so in urban areas), if stormwater is not effectively diverted away from brickwork it can not only affect the appearance of the brickwork but will dissolve and damage cement mortar joints. Inappropriate building design related to stormwater is one of the largest causes of both short term and long term damage to brickwork. In almost all cases such damage is related to either:

a minimalistic design of copings and flashings.
failure to protect brickwork from stormwater during construction.

For further information on masonry design click here.