The roofing of the house is an important element in the construction of the building. It protects the house from the harmful effects of precipitation and temperatures. The modern roof has a complex structure and consists of many elements that are mounted in series. Each layer consists of different materials and performs its function.
Due to its multilayer structure, the structure is called roof cake, which consists of:
- metal tile;
- control lath;
- vapour barrier.
The roof counter-batten for metal tiles is mounted over the waterproofing foil along the rafters. It forms a ventilation gap in the roof cake. It should not be confused with the purlins on which the metal tiles are fixed, they have different purposes.
Why do you need a control lath
Construction of a house with a cold attic does not require the installation of a control panel. If the owner of the house will want to insulate the roof in the future, it is better to immediately put a waterproofing under the metal tile and nail the counterbread.
When using the attic as a living space or attic, installation of counter lattice is mandatory. It forms a gap for ventilation of the underlay space. It promotes evaporation of a moisture from a waterproofing layer and an internal surface of sheets.
The distance between a purlin and a waterproofing allows not to pierce it with screws at installation of a metal tile. Due to the increased air space between the roofing and the insulation, the sound and thermal insulation of the roof increases.
What material is used to make a control grid?
The material for the control grid is solid wood, mainly conifers. The humidity of the material should not exceed 20%.
Controller bars should have an ideal structure, without knots and blues, which often deteriorate the strength of the control panel. They must be of equal length, width and height. This is so that there is no distortion in the installation of the battens.
Features of installation
The installation of the control panel requires compliance with certain rules:
- The bars are fixed vertically, on top of the waterproofing on rafters.
- Yarn galvanized nails are used as fasteners.
- There is an indent between the bars so that the upward air flow can move freely.
- For ease of movement on the roof during installation work, rough boards are filled horizontally on the control bar.
- Correctly and smoothly assembled control lath contributes to an even distribution of the weight of the metal roof tile on the rafters.
So, we approached the installation of the roof structure. The structure of the roof is quite complex, so it is necessary to disassemble the functions of each of its components.
Is it obligatory to have a control panel?
The roof consists of layers. Each layer has its own functions and tasks. If the roof structure is installed incorrectly, there will be various unpleasant consequences in the future.
As for an element such as a metal roof tile control bar, it is necessary to perform the following tasks:
- To ensure that the air flows under the roof. When we talk about roofing made of metal tiles, we mean that it will be good to keep warm in the house. But this type of roof tile construction often produces condensation (water from the gaseous state is converted into liquid form). So the control grid reduces this effect. The air constantly arrives under the roof, and the moisture comes out from under it.
- The inflow of air increases the insulation against unnecessary noise, as a layer of air is created.
- It is better to keep warm.
- An additional frame for the waterproofing foil.
- If the rafters turned out to be uneven, the control grid under the metal tile will safely correct the defect.
- Metal tile will serve much longer due to constant ventilation, and the rust will not soon overcome the roof covering.
- More space for thermal insulation.
- The control grid will especially help at creation in an attic room warm and cozy attic.
- But if you do not put the counter-bread, the moisture will not disappear, as a result, insulation and the wood will absorb this moisture. Then the efficiency of thermal insulation will be significantly reduced.
When to start installing the counter laths
In order to understand when to put the counter-batten, let’s take a brief look at the roofing device.
Now, the following components are required:
- The rafter structure.
- Film insulation material (vapour barrier and waterproofing).
- Contra lath.
- Thermal insulation.
Once the vapour barrier, rafters and insulation have been installed, our most interesting element is the waterproofing film.
It protects wooden components and thermal insulation from moisture. And we address it in this article because after its fixation our counter-rails are put.
So, we roll out the insulation film horizontally, starting from the bottom layer. Then we go upwards and put the next layer overlapping by ten centimetres (more is possible). And after fixing the foil, we put in the control bar.
Lath and counterpane for metal tiles
The roof is an important element of the house, protecting the house from external influences. In private construction, gable and hip roofs are the most common.The gable structures are formed by two sloping planes and should have a slope angle of more than 2.5 degrees. The hip roof structure is similar to a gable roof, but instead of two sloping planes there are four – the structure has a different slope on each side.
The main element of such roofs are rafters, which are a frame supporting all other components. The rafters are made of a metal corner or a wooden bar. The purlins are also used for fastening roofing materials (slate, profiled flooring, metal tile, etc.).
For insulation against noise, cold and moisture, a vapour and hydro-barrier is used, which also serves as protection for the insulation material. Counter-barriers promote air circulation between profiled sheets, purlins and waterproof film.
Roof ventilation is provided here by special technological gaps at the ridge and along the slopes, as well as ventilation windows. Roofing works must comply with the main principle: to create the necessary air tightness. The counterbatten is a part of the roofing system in the form of wooden bars, which are mounted on rafters on top of the hydraulic barrier. It is designed to ventilate the underlay material thanks to the gaps created.
The difference between a purlin and a control bar is as follows:
- At the device of counter-rails, they are mounted on rafters, just behind the waterproofing, the same crate is mounted on top of the counter-batten;
- The distance between the fragments of the counter-batten is equal to the distance between rafters; the battens may be continuous or with the interval depending on the roof type and roof pitch;
- The main function of the counter-batten is ventilation of the roofing material; traditional purlins are used for fastening roofing materials and rafters.
In case of slight height differences in the parts of the rafter system, the counter-bars help to level the roof slopes. The counter-batten also enables roofers to move around the structure without damaging the insulation (roofing felt, etc.).