Roofing crutch: purpose and forms

A roof spike is a fastening element that is part of the so-called auxiliary materials for roofing.

Currently, crutches of the following forms are used in construction:

• T-shaped flat;
• T-shaped double-sided;
• bent;
• Bent double-sided crutches.

The greatest application and distribution in the construction practice of roofing, received T-shaped, flat crutches.

Manufacturing of roofing crutches

Roof spikes are made from carbon steel strip. The strip is taken in the following sizes: length 450 mm, width 25-35 mm, thickness 40-60 mm.

Helpful: Band sizes can vary depending on exactly what size crutches are needed.

The strip is cut into pieces of a certain size, then bent, if such crutches are ordered, and welded, which gives the crutch its final shape. Three holes are drilled on the long side, according to the size of the dowel nails, which are then countersinked without fail.

The holes are for attaching to crate. The crutches are nailed with two nails to the wooden parts of the cornice overhang. Why do we need a third one then? The third hole is spare. It is used when one of the holes lies between adjacent boards of the crate, that is, on the "air".

When the crutch is given the desired shape, it is coated with an anti-corrosion primer and painted with a colored powder polymer.

In accordance with the standards adopted in construction, crutches are made in the following sizes: 20*4, 25*4, 40*4. But, of course, you can order non-standard sizes, with the parameters that the customer needs.

Application area

What is their area of ​​application?

1. They are used primarily in the construction of metal roofs.. The use of such roofs in modern housing construction is not so great.
   But such properties metal roof, as lightness, fire resistance and the ability to install roofs of the most complex configurations will always find their consumer.
   Plus, the old fund of metal roofs requires constant maintenance. So the demand for a crutch will always be.
   The crutch carries very important functions in the further operation of the roof:
   • This is a bearing function - it holds the weight of a sheet steel or galvanized sheet.
   • And also, when exposed to snow and wind loads on the roof, it prevents deformation changes (deflections) in the metal edge of the roof.

And this is natural, because the cornice overhangs take on the entire load from melt and rain water, snow and icicles formed, and are the zone of their maximum impact. .

Structurally, metal edge house roofs rests on T-shaped crutches. With their installation, all roofing work begins.

They are fixed as follows: according to the technology of roofing work, directly with dowel-nails to the base of the roof, while maintaining a fastening step of 600-700 mm.

1. Parapet roofing is one of the most difficult elements of roofing work, and, as you understand, we cannot do without crutches in these works either.
   In order to protect the junction of the roof to the parapets, it is necessary to install a “roof” of roofing steel on them. This roof is equipped with drips.
   A dropper is an edge of roofing steel, bent “hooked” upwards. So, with the help of a parapet apron, the parapet is protected from rain.
   This happens when water flows through drippers directly onto the parapet apron, or onto the roof. The apron is fastened with T-shaped crutches, which are installed in 1 m increments and nailed to wooden antiseptic plugs.
2. Similarly, the installation of junctions of roofs to chimneys and ventilation shafts is carried out.
3. The device of such well-known canopies of entrances in multi-storey buildings is not complete without the use of roofing crutches.

Is there an equivalent replacement

Sometimes roofing crutches are replaced with rectangular metal strips.

They do this for various reasons:

• Do not rely on the quality of welding. Allegedly, there were such precedents that the roofing crutch broke along the seam, which entailed deformation of the roof eaves.
  This reason can be described as ridiculous. Because, as everyone has known for a long time, the strength of the weld is not only not lower, but also exceeds the strength of the metal being welded.

• Metal strip is cheaper. Yes, if you take a separately taken product, then, of course, the strip is cheaper. But if you calculate how many strips are required to install the entire metal roof, then the savings are conditional.
  Because the strip must be nailed in increments of 300-400 mm, preferably 300 mm. The step of laying the crutch, as we remember, is 700 mm. In addition, the metal strip cannot provide the roof with the stability that the use of a crutch gives it.

Therefore, experienced builders are not advised to succumb to the first desire to save on such a small auxiliary material as a crutch, the absence of which can be a big and main cause of roof instability.

Important: experienced builders are advised to adhere to the following rule: if galvanized steel is used for roofing, then it is necessary that all fasteners used in roofing: nails, hooks, crutches, are also galvanized.

What have we learned from this article? We learned that there is such a fastener that belongs to auxiliary roofing materials - a roofing crutch. Find out what shape and size it comes in. That the scope of its application is not limited only to fastening the eaves of a metal roof. And that there is no equivalent replacement, this small, but so necessary, for the proper functioning of the roof and its elements!

Did the article help you?