If you've tackled a few home improvement projects by now, then you certainly heard about the term masonry. If you don't know what it means, masonry is basically the process of constructing structures from individual units that are laid in and bound together by using mortar.
Let's talk about various issues those walls encounter, sometimes caused by human error, elements, and time. Periodical professional inspections of masonry walls are crucial in detecting problems and preventing dangerous structural failures.
Solid Masonry Walls
The majority of older properties around the US, in Chicago for example, are build by making use of stone or brick masonry (full thickness), but the properties in the south which are newer make use of wood frames at the 2nd floor and concrete masonry units at the first floor. But regardless of the case though, both of these types of structures are going to deal with cracks.
In general, the normal setting of the house and the shrinkage in the mortars are two of the main factors that are going to cause this to happen. Now when the house will be inspected by the inspector, he will need to assess if the cracks are actually flaws or not. Naturally, cracks with movement or bigger cracks need to be evaluated further, since they allow water to penetrate the structure and lead to more damage.
Usually, structural inspectors assume that cracks which are bigger than one eight of 1 inch or one quarter of an inch in masonry walls require further evaluation. Better yet, if there are enough hairline cracks that add up to a quarter inch or more can signal more than usual movement. In case the cracks exhibit a vertical or horizontal offset movement, it's necessary that they're verified by a structural engineer to ensure they won't cause structural problems.
It's necessary to look for more evidence of movement that can be consequential or causative to the cracking noticed in the masonry wall. Some examples in this regard would include sloping floors, interior cracks, etc.
Assessing bulges for instance is a lot easier compared to assessing cracks due to the fact that bulges in masonry walls signal movement. Since in this case there's a high risk of failure, more evaluation should be considered at the soonest.
There are many areas that need to be carefully inspected in solid masonry walls, including penetrations in windows, but also in doors. The majority of solid masonry walls aren't barrier walls and what this means is that they do allow a bit of moisture to infiltrate, but to allow the water to escape by draining at the bottom, they depend on wythes.
In consequence, if there are horizontal interruptions in the wall, such as the top frame of doors or windows, this can lead to a slowdown of moisture penetration. When this occurs, moisture is going to be absorbed by the wood frames which will then start to rot. There's also a good chance that the moisture can penetrate the interior.
In general, older walls made of solid brick or stone masonry used mortar for strengthening purposes. The mortar a bit soft and it was made using a lime based material. As you may expect, it was indeed porous, which means that it was easy for moisture to escape between the stone or bricks.
When the mortar would eventually deteriorate, it had to be scraped off in order to install new. Keep in mind that when re-pointing / replacing the old mortar the new one needs to be the same in terms of consistency and ingredients used in original mix.
Using different ingredients is going to cause the masonry walls to absorb moisture and result in brick spalling. Spalling means that sections of the face would simply start to pop off. Due to the sensitivity of this type of job, it's recommended that you hire a professional to handle this project. Be sure he has good knowledge of vintage masonry buildings before hiring him.
While they can basically be any material, in general they're faux stone and sometimes brick. The way it works is that metal straps placed at twenty four inches on the middle each way are going to be used in order to anchor the veneers to the wood frame walls. It's necessary that the materials need to be installed with air spaces of around 1 to 2 inches between the wood frames walls and them. By doing so, it'll make it possible for the moisture to drain at the bottom and exit the wall through the weep holes.
In the majority of cases, weep holes are going to be placed at a maximum of thirty three inches on center based on the IRC. However, based on the recommendations from the Brick Institute of America, you should consider 16'' for wicks and 24'' for the weep hole.. As for the weep holes, they need to be made above grade.
Plastic mortars are then used to glue the adhered veneers to the building. Prior to starting work on this part of the project, a metal lath, but also some building paper have to be used on wood framing (external side).
After that, a scratch coat of stucco that is around three eights of an inch in thickness needs to be installed. Wait for a while until everything is dry and glue the adhered veneer on the joints and apply mortar on them. Keep in mind that moisture needs to have an exit at the lowest part of the wall.
The general conditions that require the veneers to be evaluated and repaired include the moisture intrusion into the property due to the absence of a moisture exit, blocked weep holes and the absence of weep holes.
Metal headers or lintels are used for supporting the masonry veneer above the penetrations. Therefore, it's not unusual that after several years they're going to start corroding. The problem with this is that if not serviced as soon as it has been detected, over time cracks in the mortar will become larger and might result in significant brick displacement.