- Materials for pillars
- The dependence of the installation of poles on the types of soil
- Various options for installing metal poles
The main thing that every builder strives for is to create a strong and durable structure, and the fence is no exception. How stable and strong the fence will be depends on the correct and reliable installation of the pillars and, of course, on the material that will be chosen for the manufacture of the supports..
Materials for pillars
Wooden posts, various metal profiles, concrete blocks, asbestos-cement pipes can be used as materials for the fence supports, as well as a combined version in which metal supports are lined with bricks or decorative stones.
The main criteria when choosing materials for supports are the weight of the fence and the material from which you will build the fence itself, the type of soil in which the supports will be installed, and, of course, the design and appearance of the fence.
The most popular are metal posts for their versatility in combination with various materials of the fence itself. Strong enough and resistant to stress, provided that the size is correctly selected, and, importantly, their price is not so high compared to all the advantages.
The dependence of the installation of poles on the types of soil
After you have chosen a certain type of fence and decided on the supports for it, you must choose the most correct installation method. The main factor affecting the installation method is the type of soil on the site. Each of them has certain properties and characteristics..
The main types of soils include the following:
A feature of sandy soil is the ability to strongly compact under the weight of the fence, and in fact, after installing the fence, subsidence can be noticed. Another feature of this type of soil is its good ability to pass and not retain water, respectively, and such soil freezes to a shallow depth. Considering the above features, sandstone fence posts deepen from 40 to 100 cm.
Loams include soil, the clay content of which is about 10-30%. It is an intermediate type between sandstone and clay soil, and the installation method must be individually selected in each case. Although in this type of soil, the freezing depth is not high, therefore, the supports under the fence should not be deepened too much.
In the case of clayey soil, it will be most difficult to install the pillars, since the soil is susceptible to deformations, such as erosion by sewage, heaving when freezing, compression. In this case, the installation of the pillars is carried out to the depth of freezing.
In order to determine the degree of heaving of the soil, you should know at what depth the groundwater lies (GWL – the level of groundwater), as well as to what depth the soil freezes (GP – the depth of freezing). Using the formula, we determine the value of the water level below the freezing depth (Z). And according to the table we determine the degree of heaving.
Soils according to the degree of frost heaving Index Z, m Fine sand Dusty sand Sandy loam Loam Clay Non-ungainly Z>0.75 Z>1.0 Z>1.5 Z>2.5 Z>3.0 Weakly bulky 0.5<Z<1.0 0.75<Z<1.0 1.0<Z<1.5 1.5<Z<2.5 2.0<Z<3.0 Medium porous Z<0.5 0.5<Z<0.75 0.75<Z<1.0 1.0<Z<1.5 1.5<Z<2.0 Heavily puffy – Z<0.5 Z<0.75 Z<1.0 Z<1.5
Various options for installing metal poles
The cross-section of metal pillars can be different – round, profile square and rectangular, T-shaped and I-beams – everything will depend on the design of the fence, the material from which the fence will be worked, and on how it is attached to the supports.
It is advisable to take the wall thickness of the support pillars at least 2 mm. The length of the post is taken from the calculation: the height of the fence plus the installation depth of the post.
There are a lot of options for installing metal pillars. Let’s highlight some of the most common and reliable ones:
- driving into the ground;
- combined installation;
- complete concreting.
The easiest way is to drive the posts into the ground. At the same time, it is also an inexpensive method, since no expensive special equipment is needed, except for a shovel and an ordinary sledgehammer. If you have a drill in your gardening inventory, then this will further facilitate the task..
1. Driving into the ground. 2. Combined installation. 3. Butting 4. Complete concreting
With this installation method, the depth to which the post should be driven must be at least 1.2 m in order to prevent bulging. When hammering in with a sledgehammer, do not forget to use a wooden spacer, so as not to damage the upper edge of the post during impacts.
If the soil is sufficiently soft, it is advisable to use a backfill. With this method, you will need to drill holes with a diameter of about 200 mm and a depth of about 1.5 m.At the bottom, you need to fill up 10 cm of sand and tamp it. The next step is to install the posts and fix them with wedges, followed by backfilling with crushed stone (20–40 mm) or gravel. This stage should be done gradually, in layers, and each layer should be well compacted, while pouring water.
When concreting, it is better to use a sleeve made of PVC or roofing material, which must be inserted into pre-dug holes, covered with sand outside, and a pillar inside and filled with concrete.
For greater stability of the supports, protruding plates can be welded on their lower part, which will ensure a strong and stable position of the concreted post.