Rain and snow are the main enemies of any roof. Water flowing from the roof easily penetrates into the joints of the coating with chimneys and walls, exerting a negative effect on them. To prevent the destruction of the roof and premature failure of the roofing material, an additional element such as an abutment strip is used. What is its purpose, what types of it happens and how is it mounted, we will consider in this article.
Description
An adjoining strip is a corner with different sizes of sides, made of a sheet of galvanized steel or the remains of soft roofing material. It is installed to protect the rafter system from moisture.
This element is used on rectangular roof surfaces such as ventilation shafts or chimneys.
Depending on the installation method, the protective strip can be of two types:
The upper bar is laid at the joints of the pipe and the roof (on the ridge side) on the roofing material. Most of the plank is planted under the roof so that water flowing down does not fall on the wooden crate and insulation material. The other edge is attached to the pipe using self-tapping screws.
The second option (lower apron) is installed at the bottom wall of the pipe (on the back kink of the roof) and is laid directly on the roofing.
For flooring made of profiled sheet and metal, a steel product is used, coated with a protective polymer layer.
If a bituminous tile or a roll coating acts as a roof, then the joint can be made of both metal and soft materials. In this case, the abutment bar will look like a flat strip.
Now consider the installation process of all options.
What materials and tools will be needed to install the strap
Before starting work, care must be taken to ensure that the following materials and tools are at hand:
- measuring tool (tape measure, ruler);
- hammer;
- power tool (screwdriver, grinder);
- pliers;
- wooden slats ;
- roofing sealant;
- self-tapping screws, nails;
- silicone sealant or bitumen mastic.
To begin, consider how to set the abutment bar in the case of using metal roofing material.
The process of mounting the upper strips
The abutment bar (upper) is set as follows:
- In the fracture places (where the roof will dock with the pipe), a crate with a very small step is installed.
- The sheet that will cover the kink is slightly pushed out so that it covers the joint. As a connecting element, a cornice strip is usually used . Between a sheet of roofing material and a connecting element, a special sealant (intended for installation of additional elements of the roof) is laid .
- The places of contact with the wall are fixed with screws. The height of the vertical part of the plank should be at least 50 cm. All edges are waterproofed with bitumen mastic or silicone sealant.
Mounting the bottom apron
Now we will consider how the internal apron is correctly installed (the contact bar is the bottom).
Installation technology involves the following work:
- On the walls of the pipe with the help of a marker, the height of the upper edge of the bar is marked.
- After the place of fastening of the plank is determined, a special shtroba (with a depth of at least 15 cm) is made in a brick wall (using a grinder). An edge bend will be installed in it, located at the end of the bar adjacent to the wall.
- Please note that strobing between bricks is strictly prohibited! This can lead to a violation of the integrity of the pipe.
- The resulting channel is cleaned of dust.
- The vertical edge of the strip is placed against the pipe wall, leading the upper edge into the prepared hole. The installed element is fixed using several screws. On all sides of the pipe, the straps are overlapped (15 cm) and treated with a waterproofing composition.
- Under the lower edge of the resulting structure lay a flat metal sheet (in other words - a tie), which is designed to drain water. He is sent to the valley or to the cornice.
- Then begin laying the main coating.
The device of the abutment strip on the soft roof
Soft roofing in itself is considered an excellent waterproofing material, which does not require additional protection. Soft coatings include:
- shingles;
- roll materials (eroruberoid);
- polymer membranes;
- mastic materials.
The joining level of tiles and roll coatings is arranged as follows:
- Work begins with the installation of a triangular rail, which is needed in order to raise the edge of the coating. It can be made from an ordinary bar (with a section of 50x50), sawing it diagonally. The resulting counterclone will serve as a barrier to moisture.
- A layer of bitumen mastic is applied to the plastered wall.
- Next, the installation of roofing material is carried out.
- Protective strips are installed in the corner joint of the roof and pipe cover (over the roof tiles). Usually for these purposes additional elements are used - endov. The width of such a strip is 50 cm.
- The inner side of the valley is coated with a waterproofing compound - bitumen primer or silicone sealant.
The width of the strip adjacent to the wall should be about 30 cm. In regions with a harsh climate (where a large amount of snow falls), this figure can be increased.
Useful Tips
- Before proceeding with the arrangement of junctions, pay attention to the thickness of the material used as a plank. It can be equal to the thickness of the main roofing, however, it is preferable to use elements no thicker than 0.5 cm, as they are more flexible and better take the desired shape.
- The curtains made in the brick wall must be thoroughly washed with water, as the dust left in them will interfere with the good adhesion of the silicone sealant and the base.
- The waterproofing composition should be applied only on dry surfaces.
In this article, we examined how the abutment bar is set correctly. Photos and installation instructions will help you complete these works yourself, which will avoid the cost of attracting qualified roofers.
We hope that we have answered all your questions.