Exterior wall facing

The masonry on your façade serves, of course, a decorative purpose but it also ensures that the house structure is protected. It is therefore important that it be watertight and sound.

There are two types of covering material in Montréal: clay brick and limestone. They are both assembled the same way, by layering them with mortar joints and fastening them to the structural wall (which is usually made with 100 mm wood planks).

Sometimes, bricks are used to make a solid masonry wall that is also structural. This is less common because the other construction method is simpler and, besides, more energy efficient. As a matter of fact, the weak part of a masonry wall may lie in the quality of the mortarA mixture of cement, lime, and sand used for laying bricks or masonry. jointsDevice or product for sealing a surface composed of several elements (brickwork).. Often, jointsDevice or product for sealing a surface composed of several elements (brickwork). will erode with time or due to water infiltration.The assembly will weaken and sooner or later “bumps” or dislocated masonry elements appear.

Sometimes, it may be the fasteners which will give way. One may also notice meandering cracks in the mortarA mixture of cement, lime, and sand used for laying bricks or masonry., which indicate a weakening of the foundation wall or soil subsidence. Both cases must be attended to immediately with a construction professional or a competent mason (see the aemq.com web site).

A word from an expert
CaulkingFilling material or filling the joints of an opening to make them air-tight. acts as a first line of defence against water and air infiltrations around doors and windows, along the jointsDevice or product for sealing a surface composed of several elements (brickwork). between different types of materials, around ventilation ducts and around all other types of openings in a building envelopeProtective covering elements of a building.. Water that infiltrates through these areas lodges itself between the exterior cladding and the interior finishing materials and can cause disastrous damage to the building’s structure, to its doors and windows and to the interior finish, in addition to contributing to mould development. And yet, caulkingFilling material or filling the joints of an opening to make them air-tight. is easy to apply and can be replaced at a very low cost. It is important though, to choose a good quality caulkingFilling material or filling the joints of an opening to make them air-tight. that is suitable for the project and the materials involved.”
— Albert Arduini, RMS Inspection expertise en bâtiment

It is rare that a wall needs to be dismantled completely. Because of the relatively small size of masonry elements (therefore offering a degree of flexibility), it is in most cases possible to repair only the part that presents a problem. Unfortunately, there are several “contractors” who represent themselves as masonry work specialists. These unscrupulous amateurs will needlessly “attack” the mortarA mixture of cement, lime, and sand used for laying bricks or masonry. jointsDevice or product for sealing a surface composed of several elements (brickwork).. Frequently, they will remove the mortarA mixture of cement, lime, and sand used for laying bricks or masonry. from some jointsDevice or product for sealing a surface composed of several elements (brickwork)., or, even worse, they will fill the hollow jointsDevice or product for sealing a surface composed of several elements (brickwork). with an assembly known as “line trig”.

Hollow jointsDevice or product for sealing a surface composed of several elements (brickwork). look good and it is saddening to see them disappear over the years. In addition, often these unruly repairs are only done on portions of a façade and walls, which (aesthetically speaking) is a real disaster.The quality of replacement mortarA mixture of cement, lime, and sand used for laying bricks or masonry. is also very important when repairing brick walls; a mortarA mixture of cement, lime, and sand used for laying bricks or masonry. with quicklime is much better than a mortarA mixture of cement, lime, and sand used for laying bricks or masonry. with a high cement content. And this will ensure for many years to come that the jointsDevice or product for sealing a surface composed of several elements (brickwork). remain somewhat “flexible”.

A word from an expert
Efflorescence is a recurrent phenomenon in masonry. Despite its lack of aesthetic appeal, it offers a definite advantage: it is a source of information. It consists in surface deposits of the mineral salts found in masonry materials such as brick and mortarA mixture of cement, lime, and sand used for laying bricks or masonry.. It stems from the migration of water through these materials and it is a normal process in new buildings that will become less marked as the years go by. However, it may carry on if air exfiltrations in hollow masonry walls continue to occur or if large quantities of water infiltrate the back-wall. If this condition persists, you will need to call on a certified masonry contractor who will know how to inspect the building in order to better understand what the problem might be.
— Pierre Tomassini, Tomassini et frères Ltée

Caution is the word when the time comes to clean your façade, for even if the result is spectacular at first, non-professional work will result in serious damage to the masonry if its surface, which has hardened and cured with time, is weakened. By becoming more porous, the wall will be more affected by the freezing and thawing cycles, which will accelerate its deterioration.

Masonry work should be done by artisans and competent masons. In order to assess precisely how much work is needed, don’t hesitate to call in a building inspector. Their expertise may cost you a few hundred dollars but it will save you a lot by limiting interventions on your walls to those which are necessary. Also respect original materials, don’t try to “modernize” your façade.