Lengthening the rafters - why do we need to know?
The supporting structure of the pitched roof of the building is called rafters. They consist of vertical racks, struts and laid rafter legs. The last lower ends do not rest on the walls themselves, but on the special support bar - Mauerlat.
The support for the upper ends is a beam-run, mounted on a system of vertical racks. The building design provides for a strictly defined roof structure with predefined parameters. For example, the length of rafter legs is determined by the geometric dimensions of the ramp, and their cross-section depends on the design load on the rafters. The same applies to all elements of the design.
The increase in the dimensions of beams, racks or logs in the vertical direction is known under the term "rafting", and here the axes of the two parts form a straight line. But the splice is conducted in the horizontal direction and is often applicable to the increase in the length of the rafter legs.
How to lengthen rafters so that the roof does not fall?
The elongation of the rafters is done by cutting, followed by fixation with staples, nails, bolts, etc. Tools for carpentry are diverse, and the first place among them is the ax, with which the work is carried out such as: cutting, quartering, grinding, nailing nails and staples and many other operations.
The surface, decorated with an ax, is subjected to a more thorough treatment by plane, bear, plow and sherhebel. Grooves and nests are hollowed out by chisel, chisel is used to clean cuttings. Holes are drilled with drills with different tips.
Splicing rafters along the length will require the use of a different kind of saw: the hacksaw, the beam, the transverse. You will also need a hammer and mallet. In addition, speaking about how correctly splits the rafters in length, we can not fail to mention the general requirements for cutting:
- cutting must be done in such a way that it can withstand all transmitted loads;
- at the junction of the two elements, all the plane of the slices should fit together well;
- in order to avoid decay it is desirable to take measures to prevent water ingress and stagnation;
- if necessary, use metal fasteners to resist possible accidental loads;
- , if possible, you must choose a simpler form of cutting.
Splicing rafters - how to act?
Now, after getting acquainted with the basic principles, you can think about how to lengthen the rafters at home without changing the design strength of the structure. And start with how to build rafters vertically. The easiest way is to back-end with the insertion of a pin with notches, which is necessary to contain random side loads.
A more laborious way is to build up with a spike. Here, the lateral loads will be hampered by the spike, made on the end of one log, which enters the groove cut out on the end face.
And, finally, we'll figure out how to splice the rafters along the length. There are several ways, but the simplest and most reliable methods are straight and oblique overlays. In the first case, rectangular cuttings are made at the ends of the logs to be joined by half the thickness of the beam and twice as long as the thickness.
Two logs are folded and cut by metal nails or staples. In the case of an oblique lining, the angle of the cut is much larger than the blunt angle. In principle, these are the basics of finishing the length of the beams, which should be known for non-standard layouts of your roofs.