How to knit reinforcement for the foundation scheme with photos and videos
The foundation construction technology consists of several main stages: marking, digging a trench, laying a sand and gravel cushion, assembling the formwork, knitting a frame from reinforcement and pouring concrete. All stages must be carried out in accordance with the necessary requirements and building codes, since the foundation is the basis of the structure and the slightest errors in the process of its construction can significantly reduce the service life.
A special place in the construction of the foundation is played by the knitting of reinforcement, a properly connected frame will make the structure as strong as possible. Such a foundation is not afraid of external influences and will not burst at the slightest displacement of the soil. Therefore, in this article we will analyze in detail the question: how to knit reinforcement for the foundation?
Reinforcement connection methods
Let's consider the main ways of connecting reinforcement for the foundation. Experienced builders practice four main ways of tying reinforcement to assemble various frames and meshes:
- knitting reinforcement with wire;
- overlapping rebar connection
- mechanical connection of fittings using steel couplings.
All methods have their pros and cons. In the construction of small houses, the installation of a reinforcing cage by welding or knitting reinforcement with wire is most often used.
Knit or weld armature
It is not entirely correct to compare these two methods, since these are different technologies, but still there are situations when choosing between these methods will help save time and money, without harming the strength of the structure.
Joining rebar by welding is one of the most effective ways, but using this type of rebar tying is not always appropriate. Most often it is used for mounting large frames for multi-storey buildings and heavy brick cottages.
Disadvantages of joining reinforcement by welding:
- professional skills are required or you will have to resort to the services of a welder, which will significantly affect the cost of the structure;
- reduction in the strength of reinforcing products in the places of welding;
- inability to use, for example, one of the most popular classes of reinforcement A-400 (A-III) cannot be connected by welding, it will not be possible to weld fiberglass reinforcement;
- the possibility of damage to the joints during work on the compaction of concrete with vibrators.
When building a private house, bathhouse or other structure, it is most rational to use reinforcement knitting with wire.
Advantages and disadvantages of knitting reinforcement with wire
Advantages:
- speed of work - knitting reinforcement with wire is simple and fast, but with the manual method of knitting reinforcement, the process becomes very laborious;
- it is easy to eliminate shortcomings - the frame for the foundation should not be perfectly even, but still a slight deviation or breakage during the welding connection and you will have to resort to additional operations, for example, using a grinder to remove cracked welding, and in the case of wire knitting, the broken wire can not even be removed by wrapping a new one over it;
- knitting can be done directly in the formwork;
- low cost in comparison with welding works;
The main disadvantages of knitting reinforcement with wire include the precariousness of the resulting structure.
The assembled structure has good strength, but when moving, for example, when immersed in the formwork, strength is lost, this effect is especially noticeable on fiberglass reinforcement. The fact is that the bending reinforcement changes the tension force in the knitting points, so the whole structure begins to walk, and becomes a difficult task.
Rebar tying tool
Rebar knitting with wire can be done using different techniques and with the help of different tools.
Knitting tools and accessories:
- hook;
- improvised means:
- homemade hooks;
- screwdriver with a hook;
- steel bar with a diameter of approximately 50 mm and a length of 250 mm;
- knitting gun;
- pliers or pliers.
Hook for knitting fittings
Knitting with a shop hook has two disadvantages:
- handmade;
- you need to fill your hand for good speed.
Rebar hook
As a rule, such hooks have a convenient plastic handle, a tool steel tip and practicality in work, their cost is within 1,000 rubles.
You can also find automatic hooks for knitting reinforcement in stores, although reviews about them vary. Many people talk about a small resource, others say that this tool twists a wire with a thickness of more than 2 mm with difficulty. There are also positive reviews.
Homemade crochet hook
Are you building a bathhouse? Need to tie a small frame, but do not have a tool at hand? You can make a homemade crochet hook from improvised means.
Homemade crochet hook
The material for such a hook can be a steel piece of wire of a suitable diameter, ordinary nails or other materials. As a handle, you can use various tubes, or make a wooden handle.
Screwdriver with hook
To automate the knitting process, you can use a screwdriver with a homemade hook, which is easy to make from a slate nail.
Screwdriver with a hook for knitting reinforcement
Such a device allows you to speed up the process, and with the help of the torque options regulator, the tool can be adjusted so that the tension of the bundle is maximum and the wire does not break.
Rebar tying gun
Rebar tie guns are the fastest and most convenient way to assemble foundation reinforcement cages, but the high cost of this type of tool makes this option only suitable for large-scale construction. The cost of pistols for knitting fittings starts from 30,000 rubles.
Rebar tying gun at work
The speed of work with such a tool can reach up to 2 seconds per 1 knot.
Wire for knitting fittings
The most important tool in knitting a foundation frame is a wire; the strength of the structure, the speed of work, and cost savings depend on its choice.
Knitting wire is made of low-carbon steel according to GOST 3282-74 - “Low-carbon steel wire for general purposes. Specifications".
There are also requirements for the diameter of the wire according to the diameter of the reinforcement:
- for fittings ∅ up to 12 mm, a knitting wire ∅ 1.2 mm is used;
- for frames made of reinforcement ∅ 16-18mm, use a wire ∅ 1.6 mm;
- for reinforcement more than ∅ 18 mm, a wire ∅ 2 mm or 2x1.2 is used.
Methods and schemes for knitting reinforcement with wire
You can knit wire in different ways according to different patterns. As a rule, they do not differ much in terms of economy and tightening force. The main difference is in convenience, whichever method you like best, use it.
The easiest way
This method is certainly the most convenient and common way of manual knitting of reinforcement, reviews about it on the Internet are also only positive.
This method is shown in more detail and clearly in the video at the end of the article. According to this method, reinforcement can be knitted both manually with a crochet and semi-automatically using a screwdriver.
Photo bonus mating reinforcement
A small selection of 10 photos on knitting reinforcement for the foundation.
Videos rebar knitting
This video shows how to quickly knit reinforcement for the foundation. Two different ways of knitting reinforcement are considered:
- with a hook;
- using a screwdriver with a homemade nozzle from a slate nail.
And finally, if you don’t know how to knit reinforcement for the foundation, try to improvise and come up with your own way to knit.