- 1 Are cracks around door and window frames normal?
- 2 Why do cracks occur around doors and windows?
- 3 When should a crack be a concern?
- 4 What is the main difference between a crack and a fissure?
- 5 Designing construction to avoid cracks around doors and windows
- 6 How do you seal cracks around doors and windows?
- 7 Cracks in windows due to differential settlement
- 8 Some tips to avoid cracks around doors and windows
Are cracks around door and window frames normal?
Cracks around doors and windows in construction are one of the most common aesthetic defects, when I refer to aesthetic is because in most cases these cracks are not caused by major structural damage.
Although the gaps generated by doors and windows in a building are essential, a gap in a wall, from a structural point of view is seen as a “weakness” in the structure.
Any construction work, no matter how well built, will always be subject to forces of contraction, expansion, natural settlement, and vibrations caused by various reasons.
All these vibrations and expansions can cause small cracks at certain times, especially in the most vulnerable spaces, such as door and window openings.
These cracks, from an aesthetic point of view, are not at all pleasant, because they give the sensation that “the house is falling apart”, on the other hand, many people worry because they understand that this could be the beginning of a major structural failure in their property.
Why do cracks occur around doors and windows?
Cracks around doors and windows are very common defects to see even in new construction sites.
This should not be the case, but the reality is that they occur very frequently due to several factors that I will explain below.
Doors and windows are elements that produce constant movement and impacts when opening and closing, in many occasions slamming doors that cause a lot of vibrations. These vibrations or shocks create tensions in the plaster or surface coatings.
windows are usually made of metal or wood, even PVC windows are mounted on metal frames, these materials tend to expand and contract as they are constantly exposed to moisture and heat.
These movements that occur due to expansion cause cracks around the windows, especially where there are straps that are attached to the wall.
Cementitious and plaster coatings shrink when they are set, there are cracks also due to this reason. Even water-based paints wet the plaster, which then gradually dehydrates and cracks the surface layer.
But it also happens when the thickness of the plaster is not adequate, for example, when it is less than 10 mm.
Another common cause of cracking around doors and windows is the expansion due to color build-up in the surface material.
And then there are causes of cracks in doors and windows due to the natural movements of the houses, it must be taken into account that the houses and building are settled on the ground and this can cause small cracks.
That is to say, the causes of cracks around doors and windows can be very varied, it is necessary to keep in mind that the construction materials, in general, are rigid and any movement “cracks” them. And there can be different causes or combinations of several.
When should a crack be a concern?
A crack is more severe than a fissure because of where it is found, but most importantly, it is important to keep in mind the time element.
A crack that has not increased in size for a period of time should not be a reason for worry. If it does so in a short time, however, it is an indication that it is active and should be evaluated to determine if it is an important issue.
What is the main difference between a crack and a fissure?
There is a tendency to confuse often what is a crack from a fissure, in fact, it should be called fissure to the small cracks that appear around the edges of doors and windows, but not to confuse people who seek information by the name of “crack”, I decided to leave the name the same.
A fissure is a superficial opening that is usually very fine and does not present a considerable depth in an element, whether it is a wall or the edges of a door or windows.
While a crack is an opening that represents a considerable depth and is usually wider than fissures, therefore the main difference between crack and fissure is in the size and depth of the opening.
Designing construction to avoid cracks around doors and windows
The best way to avoid an inconvenience is if you have the opportunity to avoid it from the beginning.
Although there are many reasons why surface cracks can occur around doors and windows, good design and execution at the beginning of construction will prevent or help to prevent cracks from appearing as frequently.
If you have the opportunity to build from scratch, keep in mind that the main cause of cracks in doors and windows is due to the structural “weakness” that exists in the joints of the edges due to the shear forces that act on the generated gap.
That is, the entire edge of the door and window openings should be reinforced with steel, the steel that goes from the lintels in doors and windows, and the beams at the bottom of the window should be projected to the walls that make up the opening, thus reinforcing the perpendicular joints.
The horizontal steel found in these elements that make up the door and window openings should be embedded in the vertical steel at the ends of the windows.
In case you do not have steel elements around the window openings, you must reinforce them with steel at each perpendicular joint of the windows and doors.
How do you seal cracks around doors and windows?
the elastomeric putty can be applied with a plastic or metal spatula, in the case of filling the edges of doors and windows, try to use masking tape to protect the part that you do not want to dirty with putty.
After applying the putty and removing the adhesive tape, you can smooth the application with a little liquid soap to make it as even as possible.
Cracks in windows due to differential settlement
This type of cracks caused by differential settlements in the ground is something that cannot be avoided after the construction is done.
Usually, this type of crack occurs in windows and doors and its shape is diagonal, approximately in a 45-degree direction.
The cause of this crack is the sinking of the ground because the building is settling on the ground, due to its weight, while it is under load.
Some tips to avoid cracks around doors and windows
- Drastic temperature changes can cause expansion and crack, a good practice is to use rubber weatherstripping to insulate aluminum sliding windows from the cold.
- These weatherstrips are a quick and very economical solution, they are glued around the frame, eliminating the gaps where humidity and drafts enter.
- If you are at the beginning of the construction, try to reinforce with steel the perpendicular joints of the window and door openings with steel, if the steel is tied to the vertical sides much better.
- Ensure that the plaster used around doors and windows is at least 10 mm thick.
- Prevent rainwater from accumulating on window sills by creating a slight slope or elements that prevent water accumulation in that area.
- Do not use high expansion materials with cement-based plasters, such as wood with stucco or cement, as wood has a lot of expansion and will constantly crack the plaster.