Installation and arrangement of the roof is an important and rather complicated event. The quality of the roof of the house ultimately depends on how competently and professionally the calculation is made, the project is completed, the materials are selected and the individual structural parts of the roof are made. In our article, we will talk about what a valley roof is and what is its role in the functionality of the roof.
The general concept of the valley
Valleys are the most basic structural element of the entire roof space. In fact, a valley is a roof element, which is an internal corner (a kind of tray), which is located at the junction of the roof slopes.
The most important function of the valley is to assist in the removal of precipitation from the roof space.Thanks to its arrangement, the valley, on the one hand, contributes to the removal of water, on the other hand, in this place the greatest load on the roofing system, since the valley is the most sensitive place to water.
Therefore, it is so important to pay special attention to its installation and careful sealing. The valley will drain all the water from the roof during its lifetime.
A little advice: it is best to use galvanized steel for arranging the valley. This material will extend the life of it and, accordingly, the entire roof.
Often, valleys are made in the form of planks from a sheet of metal.
Depending on the design features, there are:
- lower valley bar;
- top valley bar.
The bottom valley bar is installed at the joints formed by negative angles. Its main purpose is to protect the under-roof space from moisture ingress through the joint.
The bottom valley bar is installed even before they start laying the roofing material, for example, corrugated board or metal tiles.
The main purpose of the upper valley plank is a decorative function. It gives the joints of the two slopes an aesthetically beautiful look. Figuratively speaking, in this case, the valley forms the final appearance of the roof.
The plank of the upper valley is fixed after laying corrugated board or metal tiles.
A word of advice: choose the location of the valley attachment very carefully to avoid damage to the middle part of the lower valley. It is best to fix it with roofing screws. In order to exclude possible leaks in the places of assembly joints, it is necessary to use special lining layers.
Main types of valley:
- Closed.
- Open.
- Intertwined.
Their structural difference lies in how the panels of roof slopes touch, connect and intertwine. .
Features of the installation of the valley
The first task when installing the valley is to install the crate. It should have a continuous structure at the junctions of two roof slopes, and on both sides of them.
A waterproofing layer must be laid along the wooden gutter. This will protect the entire under-roof space from moisture penetration.
In the case when the roof valley has horizontal joints, an overlap of 100 mm or more must be performed. In the event that the slope angle is flatter, we recommend installing an additional layer of waterproofing.
It is impossible to neglect the arrangement of an additional waterproofing layer, since in the future this will result in the failure of the valley and the need to repair it, as well as the need to repair the roof itself.
It is important to know: if you have chosen a metal tile as a roofing material, be sure to use a self-expanding sealant.
Not a single roof that has a more complex design solution can do without arranging a valley. Therefore, it is so important to complete the valley in accordance with the rules for its installation.
So, when arranging a roof with a steep slope, it is necessary to use both closed and intertwined valleys. The choice of the type of valley also depends on what kind of roofing material the roof will be covered with.
It is important to consider that a design feature of a closed and intertwined valley is the mandatory arrangement of an additional waterproofing layer. And this is a financial cost.
When arranging an open valley, it is not necessary to install an additional layer of waterproofing. This can be seen from the design of the open valley - precipitation does not accumulate on it, but is very quickly eliminated.
A little advice: for an open valley, a waterproofing system is installed according to the usual technology, which is used in the arrangement of pitched roofs.
Experts recommend that you first lay the first row of roofing material to the lower end of the valley, and only then proceed with the installation of its waterproofing layer.
Now there are many construction sites on the Internet where experienced professionals share their secrets.
Most developers understand that individual structural parts of the roof require not only practical building skills, but also theoretical knowledge. Therefore, the valley roof is the most frequently asked question.
Most experts are unanimous in their opinion: you need to trust the arrangement of the valley to professionals. If you decide to install the roof yourself, do not neglect the advice of specialists - it is more expensive for yourself.
But you should not give up either: if you follow the instructions of experienced craftsmen step by step, then it is quite realistic and independently to equip the most complex structural elements of the roof, including the valley.
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