Summary
– Characteristics of wooden floors
– Step 1: Calculate the number of joists for your floor
– Step 2: Install and fasten the first two joists to the floor.
– Step 3: Install and fasten intermediate joists
– Step 4: Install the first row of decking panels
– Step 5: Lay the following rows and finish installing the flooring
A floor is generally made up of an assembly of wood panels, an ideal material for renovation or new construction. In addition to having a load-bearing function, the floor serves as a support for floor coverings. It must be laid evenly and form a flat surface to last over time. It is, therefore, necessary to comply with certain installation rules.
Here is a step-by-step guide to installing a floor.
Characteristics of wooden floors
A wooden floor consists of the following elements:
– a structure composed of beams (joists);
– an assembly of wood panels (particleboard).
Unlike other materials such as concrete slabs or metal floors, wooden floors are:
– very light;
– quick to install.
Case 1: laying a wooden floor in a new construction
A low floor can rest on a concrete slab.
An upper floor can rest on a concrete slab or preferably on solid wood beams.
Case 2: laying a wooden floor during renovation
A check of the supporting structure (beams) is necessary before laying the floor. If necessary, the elements must be reinforced or replaced.
1. Calculate the number of joists for your floor
Good to know: for a storey floor on load-bearing joists, these are installed and fixed in the wall during the construction of the house. In this case, go directly to the step of installing the panels.
In the case of a concrete slab (low floor or storey floor), the first step is to calculate the number of joists to be installed on the floor.
– Determine the joist spacing (distance between the center of two consecutive joists) based on the thickness of the panels used. This distance is between 40 and 45 cm.
Good to know: on the Internet, there are tables that give you the joist spacing according to the thickness of the panels.
– Calculate the number of joists: room width L ÷ center distance + 1 = number of joists. If necessary, round up the center distance to the next higher number.
Important: for your calculation, be sure to use the same unit of measurement for room width and center distance (usually one centimeter).
– Define the exact joist center distance: room width L ÷ number of joists = center distance width.
Accuracy: the length of the joists is equal to the length of the room.
2. Install and fasten the first two joists to the floor
Position the first two joists
– Place the first joist on the floor against one of the walls lengthwise.
– Position the second joist parallel to the first joist against the opposite wall.
– Check joist levels with a spirit level.
– Adjust them if necessary by inserting shims under the joists.
– Mark the location of the intermediate joists on the floor, according to the distance between centers determined in the previous step.
Attach the two joists
Each joist is screwed onto 3 wooden plates, which are fixed to the floor with striking plugs. There is one plate at each end of the joist and another one in the middle.
– Drill the hole for the hammer pin in the ground, aligning with the joist markings previously drawn.
– Insert the pin into its housing and hit it with a hammer to drive it in.
– Drill a hole in the wooden plate, then position it on the ground, matching the hole and the pin.
– Insert the screw and hit it with a hammer to drive it in.
– Fasten the 3 wood plates for each joist.
– Then screw the joists onto the wood plates.
Good to know: it is possible to screw the joists directly into the ground with long screws (thickness of the joists + length of the dowel fixed in the ground). However, the first method is recommended.
3. Install and fasten the intermediate joists
Fasten the intermediate joists as before.
Good to know: keep the same fastening method for all the joists.
– For each joist, fasten 3 wooden plates with hammer pins.
– Then screw the intermediate joists onto the plates.
– Check the levels at each step.
– Insert wood shims (scrap wood) every 30 to 40 cm under the joists to stabilize them.
4. Install the first row of decking panels: preparing the site for a floor on load-bearing joists
In the case of a storey floor on load-bearing joists, there is no slab. The joists are above the void.
Important: make sure you are able to work in this situation, high above the void.
– Route the panels upstairs and lay them on the joists.
– Position a panel where you are working. It will serve as a support for the first panels.
Install the first panels
– Allow for a 10 mm expansion joint around the entire periphery of the floor.
– Place the first-panel perpendicular to the joists, positioning the tongue against the wall and the groove on the free side.
Good to know: chipboard panels are provided with tongues and grooves.
– Locate the location of the joists by drawing lines on the panel in the extension of the covered joists.
– Present the following panels and lay them on the joists so as to obtain a perfect alignment. Always mark the location of the joists on the panels.
– At the end of the line, make the necessary cuts.
◦ Measure the overlapping part.
◦ Transfer the measurement to the panel with a margin of a few millimeters to allow for the insertion of the last panel in the row.
◦ Cut with a jigsaw or circular saw.
Good to know: the scrap can only be used for the next row if it can rest on at least 2 joists.
– Insert the cut-out in the groove of the previous panel using a large screwdriver.
Fasten the first row of panels to the joists.
– Drill pilot holes in the panels:
◦ in 3 points every 15 cm on the end supports;
◦ in 2 points every 30 cm on the intermediate supports.
– Then screw the panels into the joists with wood screws of sufficient length:
◦ 1/3 of the screw into the panel;
◦ 2/3 in the joist.
5. Lay the following rows and finish laying the flooring
– Continue installing the panels in the same way as before, taking care to offset the joints from one row to the next.
– Fit the panels into those of the previous row by tapping gently with a mallet.
Good to know: place a piece of wood (martyr) between the hammer and the panel to avoid damaging the grooves.
– Make sure that the panels are joined and that the joists are properly supported.
– Fasten the panels after each installation of a full row.
– For the last row, use a large screwdriver to slide the panels into the panels of the next-to-last row.