Which pointing mortar should you use for reclaimed bricks?

Which pointing mortar should you use for reclaimed bricks?

There is no single standard pointing mortar that automatically suits all old bricks. The right mortar depends on the hardness and suction of the brick, the existing mortar, the construction of the wall and the conditions to which the masonry is exposed.

This matters particularly in historical brickwork. A joint must not only look appropriate: it must be technically compatible with the brick and the structure. An unsuitable mortar that is too hard can be detrimental to relatively soft old bricks.

Why is the right pointing mortar important for old bricks?

Joints make up a substantial part of the visible facade and affect both appearance and moisture behaviour. In restoration, mortar therefore needs to be chosen in relation to the brick.

The hardness, porosity and water absorption of reclaimed masonry bricks can vary considerably between batches. A mortar that works well with a hard modern facing brick is not automatically the best choice for a softer historical brick.

Lime mortar, lime-cement mortar or cement mortar?

These mortar types differ in strength, ability to accommodate movement and moisture behaviour, among other properties. A suitable composition cannot be selected on the age of the brick alone.

Lime mortar

Lime-based mortars are common in historical brickwork. They are generally less hard and more able to accommodate movement than strongly cement-rich mortars. This can make them suitable for certain soft, porous old bricks and traditional wall constructions.

It does not mean that every old facade must be pointed exclusively with pure lime mortar. The existing situation and technical demands remain decisive.

Lime-cement mortar

Lime-cement mortar combines lime and cement. Depending on the proportions and composition, it can offer properties between those of traditional lime mortar and stronger cement-rich mortar. This type is used in a range of renovation and masonry applications.

Here too, the strength must suit the brick. The description ‘lime-cement’ does not in itself establish whether a specific mortar is suitable.

Cement-rich mortar

Cement-rich mortars can be relatively strong and hard. That can be appropriate for hard bricks and certain modern constructions, but a joint that is too hard may be undesirable for softer historical bricks.

When the joint is much harder than the brick, stresses and moisture exposure can concentrate unfavourably in the brick. ‘As strong as possible’ is therefore not automatically better in restoration masonry.

Should the joint be softer than the brick?

A common restoration principle is to choose mortar with properties that suit the brick and that is not unnecessarily harder than the historical masonry. How this is applied depends on the brick type, existing mortar and structure.

For valuable or vulnerable historical brickwork, analysing the existing mortar can be sensible. This avoids choosing solely by colour or a standard recipe.

How does the suction of old bricks affect the mortar?

Bricks absorb water from fresh mortar. The rate varies by brick. A high-suction brick can draw moisture out quickly, while a dense brick absorbs much less.

Working methods need to account for this. Water being removed too quickly can adversely affect bonding and hardening. Weather also matters: hot, dry and windy conditions require a different approach from cool, damp weather.

If you intend to reuse old bricks, also read our explanation of laying reclaimed bricks.

Which joint colour suits old bricks?

Joint colour has a surprisingly large influence on the overall facade. A light joint emphasises individual bricks and can make the masonry look brighter. A dark or more subdued joint can make the bricks read more strongly as a single surface.

Restoration often takes the original or existing pointing as its reference. If in doubt, create sample areas: mortar colour can look noticeably different once dry than during application.

Joint profile and brick bond

Not only colour but also joint profile and depth affect the appearance. Flush, recessed or otherwise finished joints give the same brick a different facade appearance.

The combination with the masonry pattern matters too. For background, see our explanation of different brick bonds.

Removing old pointing: work carefully

When repointing, enough of the old joint must be removed to allow for sound new pointing. The bricks should not be unnecessarily damaged in the process.

Grinding or chiselling out joints requires particular care around old handmade bricks and other bricks with irregular edges. Damaged edges remain visible after pointing and can harm the historical appearance.

Pointing and damp problems

Worn, eroded or cracked joints can contribute to rainwater entering a facade. New pointing may then be part of the repair, but it does not automatically resolve every damp problem.

First establish whether the joints are actually the cause. Also read our article on damp in the walls of an old house.

Reusing reclaimed bricks: choose mortar and pointing together

When a reclaimed batch is laid again, consider the mortar, joint colour and finish before bricklaying starts. This avoids discovering afterwards that the chosen pointing does not suit the intended appearance.

A sample wall or panel is often worthwhile for larger projects. It shows directly how brick, sorting, mortar colour, joint width and finish work together.

Our projects using reclaimed building materials also show how much difference the combination of brick and pointing can make to the final facade.

Frequently asked questions about pointing mortar for old bricks

Can I use ordinary cement mortar with old bricks?

Not without assessing whether its properties suit the brick and the structure. Very hard cement-rich mortar can be unsuitable, especially for relatively soft historical bricks.

Is lime mortar always the best choice for reclaimed bricks?

No. Lime mortar can be very suitable for historical masonry, but the right mortar depends on the brick, existing mortar, wall construction and exposure. There is no universal recipe for all old bricks.

How do I choose the right joint colour?

Consider the desired facade appearance and, in restoration, the existing or original situation. If in doubt, make several sample areas and assess them only after the mortar has dried.

Can poor pointing cause damp?

Damaged joints can contribute to rainwater absorption. Damp in a wall can also have other causes, such as leaks, condensation or problems with junctions and drainage.