Brick Wall Construction Guide

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.

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.

​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.

Clinkers are defined by their hardness and are machine made.

While most of the bricks we offer are new handmade or pressed bricks, we do offer a limited range of reclaimed bricks (Cottage Reds, Prague Greys, Jerusalem Whites, 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.

As the name suggests, extruded bricks are manufactured by forcing clay under pressure through a shaped die before being cut to length and fired. This production method results in bricks that are generally more consistent in size and shape than handmade alternatives.

The vast majority of bricks produced worldwide are manufactured using the extrusion process. While we also offer a selection of extruded bricks, they are quite different from the highly refined products typically found on the market.

Our extruded bricks are produced using deliberately primitive manufacturing techniques that align with our perfectly imperfect philosophy. Rather than striving for a flawless, factory-made appearance, they retain the character and authenticity associated with early extrusion methods. Tool marks, subtle surface irregularities and natural textural variation are all intentional features, giving each brick a handcrafted feel and ensuring the finished masonry has depth and individuality.

The result is an extruded brick that combines the greater dimensional consistency of machine manufacture with the timeless character traditionally associated with much older brick making techniques.

Highly uniform, square-edged extruded bricks are more susceptible to edge chipping, which is an inherent characteristic of this style of brick rather than a product defect. Chipping must be expected and accepted when selecting a brick with a crisp, precise profile. The use of flush mortar joints is recommended, as this helps soften the visual impact of edge chips and creates a more cohesive finished appearance.

We’d like to think the answer is a resounding yes, but choosing handmade and our old school extruded bricks bricks is ultimately a decision that should be guided by the architectural style and overall aesthetic you want to achieve.

If you’re looking for bricks with genuine character and individuality, our bricks are an excellent choice. Their rich variation in colour, texture and subtle imperfections creates a timeless appearance that simply cannot be replicated by highly uniform machine-made products.

Because each brick is handmade or made using old school processes, natural size variation is also part of their appeal. A dimensional tolerance of up to ±5 mm from the nominal size is typical and should be expected. These variations are not defects but are an inherent characteristic of authentic old school bricks, contributing to their distinctive handcrafted appearance.

On the other hand, if your project demands absolute uniformity in colour, texture or size, our bricks may not be the right product for you.

Our bricks possess a naturally aged character and embraces the philosophy of being perfectly imperfect. Colour variation between individual bricks and from batch to batch is an essential feature of the product, ensuring every wall has its own unique depth, texture and personality.

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 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.

All bricks are porous to some degree. They absorb moisture and can wick water through the masonry. Damp-proof courses (DPCs) are installed to create a physical barrier that prevents moisture from the ground travelling upward through the brickwork.

When a DPC is missing, incorrectly installed or bypassed, rising damp can occur. This can lead to unsightly staining, efflorescence, brick fretting, and in persistently damp conditions, mould growth.

Under the National Construction Code (NCC), DPCs must be correctly positioned in relation to the surrounding ground and finished surfaces. As a general requirement:

• The DPC should be located at least 150 mm above the adjacent finished ground or landscaping level, subject to the specific construction and paving conditions.
• The DPC should remain visible and unobstructed, allowing its position and clearance to be readily checked.
• Landscaping, garden beds, soil, mulch, paving, paths, decking or subsequent building work should never bridge or bypass the DPC, as this can provide moisture with a pathway around the barrier.

Unfortunately, incorrectly installed DPCs and landscaping that later bridges or bypasses the DPC occur far too often. These mistakes may not cause obvious problems immediately, but they can result in persistent and expensive moisture-related issues over the longer term.

Make sure your DPCs are installed correctly, at the correct height and remain visible throughout construction and landscaping. Pay particular attention when final ground levels, paving and garden beds are being established. A correctly installed DPC can only do its job if nothing is allowed to bypass it.

To achieve the required clearance above the finished ground level, the DPC will typically need to be installed several brick courses above the slab, rather than simply at the point where the brickwork meets the slab. If its installed at the slab/brick interface, this means you need to have the slab exposed (i.e. the slab will be above the landscaping level.

In many situations, installing two DPCs can be an excellent approach: one at the slab/brickwork interface and a second DPC higher in the wall at the appropriate level above the finished ground or landscaping. This provides an additional line of defence against moisture movement and reduces the risk of the damp-proofing being compromised by future paving, landscaping or changes in ground levels.

The important point is that the effective DPC must remain correctly positioned, visible and above anything that could bridge it.

Raising landscaping, paving or concreting against the brickwork after construction will effectively defeat the DPC and create the very rising-damp problem the building was designed to prevent.

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, it is essential that the bricks are blended during laying. 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, Weathered Parliament) 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.

The shaping of the mortar within the joints is an important element to the final finished look but more importantly the function of your brickwork. 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) . We do not recommend raked joints as it allows water to pool within the joint which can lead to frost shattering and/or fretting, 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 and increase the likelihood of ongoing brick maintenance. In near marine or saline environments flush joints are the preferred joint and raked joints should not be used as per NCC 5.6.4(2).

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.

Mortar extruded from masonry joints during laying should be cut off with a trowel. In this way a clean cut can be made with little smearing on the brick face. On completion of laying and joint tooling, mortar smears on the work face should be removed by dry brushing. Wet sponging of the mortar joints is a common practice with smooth face bricks, however, it is NOT recommended by us or Think Brick Australia. Although sponging creates a smoother joint finish, it smears a cement-rich mortar film over the brick face that often develops into difficult to remove staining. Sponging of joints is only recommended for Jerusalem White bricks.

Sand beige 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.

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

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.

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.

Red mortars can work extremely well with red bricks, red mortars require a red oxide combined with white cement and either white or yellow brick sand. An example of red mortar brick work can be seen here.

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 that the true colour of a mortar is not apparent until it is 100% dry. Poorly batched mortar is a common source of effervescence as too much cement and/or lime is used in the mix.

Freshly mixed mortars should have a pH >12, over time this will decrease to between 7 and 9. Care should be taken in areas where sands are known to be acidic and such sands should never be used in mortar mixes. Mortar additives are typically highly sensitive to mortar pH (e.g. Efflock) and calibrated for use in highly alkaline mortars. More acidic mortars can cause increased efflorescence and brick fretting.

Mortar is made from carefully proportioned water, cement, sand and lime. While these ingredients are essential to producing a durable mortar, the sand naturally contains varying amounts of mineral impurities, including iron compounds.

When fresh mortar is wet, its highly alkaline nature allows small amounts of iron to dissolve into the moisture (and other impurities, but iron is the most common). This moisture is then absorbed by the dry brick and gradually migrates to the surface as the wall dries. As the water evaporates, the iron (or other impurities) is left behind and oxidises, creating staining that typically ranges from light pink through to orange.

On darker bricks this staining is often barely noticeable, however on white and very light-coloured bricks it can be much more apparent. The extent of any discolouration varies from project to project and depends largely on the natural iron content of the sand used in the mortar. Because this is a naturally occurring characteristic of the raw materials, it cannot be completely prevented or controlled.

Where staining does occur, it can often be reduced or removed, with varying degrees of success, using an oxalic acid cleaner applied after construction. However, anyone choosing white bricks should understand that this is an inherent characteristic of masonry construction. White bricks naturally reveal staining and weathering more readily than darker colours, and a degree of visible discolouration should be expected and accepted as part of their long-term appearance.

• 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 0.3m 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.

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. Pale Sanded Greys, Roman Pale Sanded Greys, Weathered Parliament, Vintage Stock, Ironbark Grey)

HCl should not be used to clean Antique White bricks, we suggest an appropriate Oxalic acid solution and as always test a small section of wall. The use of HCl can cause vanadium stains to become permanent.

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. 

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.

Our reclamation styles and reclaimed bricks (excluding Jerusalem White bricks), which can be identified by the white scumming/mortar 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.​

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

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, if the mortar mix is excessively wet or if the bricks get excessively wet (during construction and/or storage).

Ways to limit Vanadium Efflorescence

• Using a stiffer mortar mix;
• Keeping brickwork dry during construction;

Over time Vanadium efflorescence 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. Methods can be used to help minimise vanadium staining but if you are concerned about this process we would advise against the use of light coloured bricks.

Iron Staining

The most typical source of iron staining is from iron liberated from the sand used in the mortar mix, this liberated iron is absorbed by the brick and evaporates at the brick surface leaving behind a pink to reddish discolouration. Oxalic acid and water can be used to remove iron staining.

General Staining

White bricks are, by their nature, more susceptible to showing dirt, stains and environmental marking than darker coloured bricks. Choosing white bricks means accepting this characteristic as a normal part of the product’s appearance over time.

Staining can result from a range of natural and environmental sources, including oils and tannins from overhanging trees, airborne pollen, dust, general urban pollution, stormwater runoff, and other contaminants that are present in the surrounding environment. These factors affect all exterior building materials to some degree, however they are naturally more visible on lighter coloured surfaces. Regular cleaning and maintenance will help preserve the appearance of white brickwork, but some level of visible weathering should be expected throughout the life of the building.

While sealing white/light coloured brickwork is not a requirement, it is a sensible option that should be considered, particularly in areas exposed to heavy vegetation, high levels of airborne contaminants, or where maintaining a consistently clean appearance is a priority. A quality breathable masonry sealer can help reduce the absorption of staining agents and make future cleaning easier. Sealing will not prevent all staining, nor does it eliminate the need for maintenance, but it can provide an additional level of protection and simplify ongoing care.

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.

There are many advantages to brick sealing, for light coloured bricks it helps prevent stains and for tinted bricks (Weathered Parliament, Ironbark Grey, Roman Pale Sanded Greys, Pale Sanded Greys) if you don’t want them to weather naturally into their environment (e.g the same reason you choose to either seal timbers or not to seal timbers. Many brick sealers exist, common sealants include Crommelin brick and render sealer, Efflock HYDROPHOBIC SEALER FOR MASONRY, Just Seal It or Bondcrete. Brick sealers typically have strict instructions in regard to application which you must follow. Whatever brick sealer you choose to use test on a few bricks first before sealing large expanses of wall. In all cases sealing should be done immediately after brick cleaning once brickwork is 100% dry. Brick cleaning should be done within 2 weeks of the brickwork being finished (preferably within 7 days). Sealing brickwork long after brickwall construction allows dirt and pollens to build up on the bricks surface which may cause issues with sealant curing, this will be evident when you do the test sealant on a few bricks. Bricks may need to be resealed over time.