- Situation assessment
- Striking zero and finding the highest point
- Installation lag
- Installation of corrugated board
- OSB installation
How to do without heavy reinforced concrete floors and organize a lightweight and reliable floor in the attic with wooden beams? Read in this article about the technology for the manufacture of lightweight ceilings based on corrugated board.
Quite often, for one reason or another, the developer refuses heavy and expensive reinforced concrete floors, preferring ordinary wooden beams. And here’s a classic situation: you bought an unfinished house with partial interior decoration, where the attic was not planned at all. But the height allows you to organize one or two rooms here. Do not waste the same free square meters. The main task in such cases is to make the floor.
There would be a solid support, and the rest is a matter of technology. And organize the plasterboard partitions and stretch the heating, in general, whatever you say, but you need to start with the overlap.
On wooden beams, two types of floors are most often used. These are floors made of wood and floors based on corrugated board. The tree will cost the developer almost half the price (1 m2 pine boards 40 mm thick will cost about 200 rubles, while 1 m2 corrugated board about 350 rubles), but the iron is much lighter (1 m2 corrugated board H60 weighs 10 kg, while even dry pine from 18 kg) and harder. It is these two qualities that determine the choice most often in favor of a foundation made of corrugated board.
Before starting work, it is necessary to assess the situation and outline a general plan of measures.
Ideally (to do without dismantling works) we have a “bare” system of beams installed between the load-bearing walls at 90 cm intervals. Of course, this state of affairs does not suit us. So the number one task will be to build a plane in the attic..
Striking zero and finding the highest point
To do this, we first need to determine the lowest and highest point in our existing beam system. The task, of course, will be greatly simplified by the presence of a laser level, but if there is none, you can do with the usual hydro level. To do this, we screw “flags” to the extreme beams, vertically installed slats 50–80 cm high. “Flags” are installed at intervals of 1.5–2 m, and it is on their surface that we beat off zero. Pull the painter’s thread between the zero marks of the opposite “flags” and take measurements from it. The place with the smallest distance between the thread and the bar will be the highest point of the beam base, and the place with the highest value will be the lowest.
Based on the received data, we mount the lags. As the latter, we use a 50 mm thick edged board.
We begin installation with the penultimate beams (on the last we have set the “flags” that we still need). Using a tape measure and the zero point we knocked off to the side of the timber, we fasten the edged board to the self-tapping screws, taking into account that it is 2 cm higher than the highest point of the beams (we reinsure ourselves in case the highest point is between the “flags”). We do the same operation with a bar and at the opposite end of the room. In order to check the resulting plane, we will use an ordinary painting thread. The laces stretched crosswise between the opposite ends of the fixed lags should barely touch each other, and not push one another. If everything is correct, we fix the logs more thoroughly with a bolted connection. That is, using a drill through the board and the beam, we drill through holes with a diameter of 10–12 mm. The bolt used must be of the same diameter and fit tightly into the hole. The step of fastening is 70–100 cm. When the logs are fixed, you can pull the lacing between them and expose the rest of the boards. The last ones are to install the logs on the extreme beams. To do this, remove the already unnecessary “flags” and, relying on the rule on the constructed plane, set the edged board to the level with it.
Important: in order to facilitate the installation of edged boards, we first mount them on self-tapping screws and only then thoroughly tighten them with a bolted connection.
Installation of corrugated board
The next step in the manufacture of our floor will be the installation of corrugated board. The corrugated board should be taken only bearing galvanized, grades H60, H75, H114. Desirable thickness is 0.8 mm and more. We lay the iron across the log, overlap. We attach it to the edged board using press washers. We make installation in each wave touching the log.
In places of overlap, it is useful to fasten iron sheets together with “fleas”, this will facilitate the installation of OSB in the future.
Before installing OSB, cover the corrugated board with a foamed polyethylene film (Gemafon) 5 mm thick, this is done for sound insulation purposes.
We select Rated Sheathing OSB sheets with a thickness of 11.1–11.9 mm as a rough flooring. This brand is specially designed for this kind of work..
Installation is carried out according to the principle of laying the laminate, the rest of the last sheet in the first row will start the second row. If the sheet lays down without a remainder, the next row starts with half of the sheet. We lay OSB across the waves of the corrugated board and fasten to the latter using metal screws 25×3.5. The step between the screws should be 15–20 cm. Installation is carried out in each wave. In no case do we fit the sheets tightly, there should be a gap of 2-3 mm between them. And between the shield and the wall – 4–5 mm. OSB cake consists of 2 layers. If the first layer was mounted, for example, along the room, then the second one lies across. For mounting the second layer, we use a wood screw 3.5×25.
On such a rough floor, you can easily mount plasterboard walls, lay linoleum or laminate on it, and if necessary, such an overlap can be easily insulated by laying a mineral wool “pillow” under the corrugated board.