Installing flooring on subfloor joists is one of the most popular ways to make wooden floors. Besides, today there are many methods of such installation. Of course, this also applies to mansard and attic floor covering.
Floor joists must be strong enough and able to bear heavy loads. That is why you should think not only about the structure of the future floor, but also the material, which they are made of. Dry wood treated with fire retardants is the best option.
Joists are embedded between the log rows at a predetermined height. This is done with a margin of 5-7% accounting for house settling. The areas of insertion are marked in advance, after which kerfs are made in the wood. Then joists are put into place. Elements of the structure should fit together as closely as possible.
The distance between joists tends to be 600mm, which ensures maximum floor durability. The estimated load should amount to 300 kg per 1 m².
Moreover, floor beams of the first floor and their shape play a large decorative role in the interior of the ground floor. Beams can be made of round logs and timber of various profiles.
Thermal insulation of wooden subfloor sheathing
The installation of thermal insulation is an important component of the entire installation work.
A common variant of insulation for such floors - a layer of mineral basalt wool or its substitute 10-15 cm thick. Do not forget about waterproofing.
Before installing the insulation, a subfloor is fitted - from the bottom, boards or boards are hemmed or the boards are fixed to the sides of the log with the help of cranial bars of rectangular cross section. It is possible to cut such elements from boards 5–6 cm thick. The process of warming wooden floors on logs always begins with laying a layer of hydro- and vapor-insulation. Any rolled or sheet material on a polymeric or bituminous basis will be suitable. His sheets are laid between the joists and attached to them with a stapler. Top stack insulation. The resulting gaps are filled with foam. A layer of penofol is put on top of the insulation (it can be replaced with foil or plastic wrap). And then mount the finish coating.
Calculating subfloor sheathing parameters
Dimensions, materials and other parameters of the joists are not universal. Different types of wood can be used to create them. Regardless of the type of wood, the design of the wooden floor on the joists has the following advantages:
- a fairly wide gap between the joists makes it possible to lay between them not only electric cables and insulation, but also pipes;
- wooden supports withstand heavy loads;
- this kind of construction is lightweight;
- the floor plane can be displayed at any height;
- floor joists are affordable and inexpensive;
- such boards are very easy to repair and the entire floor is not required during the repair process;
- this design allows the use of truly effective insulation and noise insulation.
As a material for the manufacture of joists is better to choose softwoods. Billets must have a moisture content not exceeding 12%. The height of the joist can be selected from the calculation of the thickness of the future insulation.
The distance between the joists is calculated based on the thickness of the finish coat. Their proportion can be represented as follows:
- Board 2 cm - a gap of 30 cm;
- Board 2.4 cm - a gap of 40 cm;
- Board 3 cm - a gap of 50 cm;
- Board 3.5 cm - a gap of 60 cm;
- Board 4 cm - a gap of 70 cm;
- Board 4.5 cm - a gap of 80 cm;
- Board 5 cm - a gap of 100 cm.
Installing subfloor sheathing
Having considered the general scheme of laying a wooden floor and its thermal insulation, you can dwell on the installation of the logs themselves. They are the main element of the floor frame.
The first joist is set at a distance of 2-3 cm from the wall. Next, the gap between the control line and the upper edge of this joist is measured. In accordance with the mark, put the next structural member. It should be located on the opposite wall. On the tops of the two extreme wooden joists the cord is pulled. With its help, the remaining elements are set by level. When building a log house, we immediately cut logs into the walls, in accordance with the specified design dimensions and shape.
In order for the logs to remain securely fastened, they are fastened together by additional rails. Sometimes installed wood elements have irregularities. They are eliminated with a planer.
Wooden floors on logs can be quite strong even with a fairly large distance between the logs, if thick boards are used for the finished floor. Otherwise, the gap between the joists should not be too wide, otherwise the floorboards will sag and break over time.
Finally, here are some tips for installing floor joists:
- boards must be pretreated with compounds that protect the wood from insects, microorganisms and moisture;
- the finish coating is attached to each joist;
- boards can be pairwise connected to each other to get the material of the desired size;
- the ends of the structural elements must not touch the walls of the building: a clearance of at least 5 cm.
Wooden subfloor sheathing is just one of the elements of the design. In order for the floor to be as reliable and durable as possible and to last for many years, it is necessary to take care of other components, including the covering and waterproofing.