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When remodeling an apartment or building a private house, you have to install new partitions. Finding material for them is not so easy. It should not create an excessive load on the ceiling, it should be reliable and have a good bearing capacity. And it is also desirable that the installation is simple and fast, and the price is low. There are not so many materials and technologies that meet these requirements. These are plasterboard partitions and tongue-and-groove slabs. In this article we will talk about the tongue-and-groove.
What is this material and its types
Tongue-and-groove slabs (abbreviated as GWP) or blocks are large-format building material for the construction of partitions in the form of a slab, on the ends of which a comb (thorn) and a groove are formed. Hence the name – tongue-and-groove slabs. They are:
- based on gypsum (cast gypsum);
- from sand and quicklime, pressed under a certain pressure and treated with steam in an autoclave (silicate).
Dimensions of gypsum tongue-and-groove blocks according to GOST and TU
Plasticizers and hydrophobic (water-repellent) additives are added to the solution to improve the properties. Gypsum GWP has another name – gypsum boards. It is understandable: the gypsum mortar is poured into molds. Here is the “source” of this variant of the name.
Moisture resistance and void
According to the area of use, tongue-and-groove slabs can be intended for normal operating conditions (normal, standard) or for wet rooms (moisture resistant). Moisture resistant for the best identification are tinted in greenish color.
Both gypsum and silicate tongue-and-groove slabs are solid and hollow. Solid ones are more durable, hollow ones, due to their lower weight, create less load on the floors. The choice between solid and hollow should be made based on several factors:
- Soundproof characteristics. A monolithic material without voids conducts sounds better, so it is used if the sound insulation will be made in a separate layer (the best option) or if it is not so important.
- Partition loads. If you need to hang shelves, furniture on the walls, fix some heavy objects, it is better to use a monolith.
- Floor or floor load. On a wooden floor or on old wooden floors, it is better to put less heavy (hollow) blocks.
If you need to consider several factors, soundproofing is considered last. It is possible to increase noise protection using a special mounting technology (on vibration-damping pads), as well as by making an additional layer of sound-proofing materials.
TECH SPECS
If we compare ordinary and moisture-resistant tongue-and-groove plates, the differences in characteristics are only in water absorption and strength. Moisture resistant, due to the large number of hydrophobic additives, they almost do not absorb moisture. Due to the large number of these additives, they are more expensive, since these additives are expensive. At the same time, they increase strength (M50 compared to M35).
By the way, you can check “on the spot” whether you really have moisture-resistant GWPs or just standard ones painted green. Just pour some water on the surface. Standard plates will quickly absorb it, and on water-repellent ones it will stand in a puddle for a long time.
If we compare gypsum and silicate partition blocks, the increased strength of the latter immediately catches the eye – M150 compared to M50 and M35. That is, the strength of silicate slabs is comparable to concrete of not the worst brand. If you are going to hang something very heavy on the partition, it is better to use silicate. Manufacturers also produce blocks with a thickness of 115 mm, which are called inter-apartment.
How else do silicate boards differ from gypsum counterparts? The fact that in the standard version they do not have such a high absorbency. It is not as low as moisture-resistant blocks, but this material can be used without problems in any wet areas (13% compared to 26-32%). The disadvantages of this material are greater weight (with equal dimensions) and lower thermal insulation characteristics.
silicate or gypsum?
If we compare the soundproofing characteristics of gypsum and silicate blocks, the latter, with equal parameters, conduct sounds worse (40-43 dB for gypsum and 48-52 dB for silicate). So for better sound insulation we choose silicate.
But silicate blocks of the same size have more weight and higher thermal conductivity (conduct heat better). The key in choosing is weight, since sound and heat insulation can be improved with the help of additional layers of special materials, but there is no way to reduce the weight of the partition. And if its mass is critical for overlapping, nothing good can be expected.
How to build from tongue-and-groove slabs
In order for a partition made of tongue-and-groove blocks to be reliable and stable, certain conditions must be met:
- Place the blocks on a perfectly flat base with height differences of no more than 2-3 mm per meter. It must be aligned in all planes. On concrete bases, a leveling screed is poured (minimum thickness 3-5 cm), a dry, even beam is placed on wooden floors.
- Masonry is carried out by analogy with brick – with dressing in the middle. Special or tile adhesive is used. With silicate blocks, you can use a mortar for laying foam blocks.
- The partition must be strictly vertical. A deviation of even one degree leads to instability, so control by the usual building level is insufficient. Can be controlled by laser level and/or plumb bob.
It looks like a finished partition from a tongue-and-groove comb separating a bathroom in a new building - The maximum height of a partition made of tongue-and-groove plates is 3,5 meters, the maximum length is 6 meters.
- A gap of 20-30 mm must be left between the top of the PGP partition and the ceiling. This gap is filled with mounting foam.
- To give greater stability, it is desirable to strengthen the connection with the ceiling by hammering the pins and walling them inside the blocks (not between the seams, since the seams are very thin).
- The sound insulation of the tongue-and-groove partition is not too high. To make your life comfortable, use a cork or bituminous lining under the wall, and sheathe the walls on both sides with drywall. Such a “pie” creates comfortable living conditions.
In general, it is necessary to strictly follow all the recommendations, strictly follow the technology. Then tongue-and-groove partitions do not differ in strength and reliability from brick ones, but are built many times faster.
Layout
The laying of the partition wall from the tongue-and-groove begins with the markings. If you have a laser plane builder, everything is simple: you unfold the plane, draw lines on the floor, walls, and ceiling. If there is no such tool, you will have to spend more time. A plumb line will be required. The one that does not fit in a smartphone is not a measuring tool. It is better to buy at a hardware store or make from twine and a centered weight.
We draw the first line on the ceiling, with the help of a plumb line we transfer it to the floor. By connecting the points on the floor and ceiling, we get the lines on the walls. As a result, a closed marking was formed to align the partition.
We examine the base on which we will put the blocks. It should be perfectly aligned when viewed along the dividing line, and should not lean forward or backward when viewed across.
If there are door or window openings in the partition, they must also be marked. With the door, everything is simple – we designate them on the floor. It is more difficult with window ones – beacons are needed on the walls and ceiling.
Substrate preparation
As already mentioned, the base must be perfectly flat without a roll in any direction. If there are deviations, we pour a leveling screed on the concrete floor (concrete grade not lower than M150). To do this, you will have to assemble the formwork into which the solution is poured. The minimum layer thickness is 3 cm. To get a guaranteed quality result, use a self-levelling compound. Just keep in mind that “they level themselves” are not too large errors. You still need to distribute the composition manually. Just run with a spatula, dispersing the solution along the entire length, and small irregularities are leveled due to the increased fluidity of the material.
We cover the poured concrete with polyethylene, leave it for about a week. This is if the temperature in the room does not fall below + 20 °, during this time it will gain 50% strength. This means that you can work with him. If the temperature is lower, the period increases. At a temperature of 17 ° C and a little lower, we need 2 weeks already … We coat the even base with concrete contact – it will improve the adhesion of the base to the adhesive composition, on which we will put the GWP.
If we put tongue-and-groove blocks on a wooden floor, the partition should pass over the beam – this is the time. Second – we level the base with a dry beam. It must be fixed so that it is also aligned horizontally in all directions. We fix the beam to the floor with nails or screws. If there is a joint, we connect it into half a tree, additionally smearing the joint with wood glue and fastening it with nails.
To improve sound insulation
The main disadvantage of gypsum tongue-and-groove partitions is not too high sound insulation. For silicate blocks, the situation is better, but also not ideal. Therefore, we recommend laying vibration-damping tape along the perimeter of the partition. It’s no secret that most of the sounds are transmitted through vibrations through the floor, ceiling and adjoining walls and elastic pads greatly improve the situation.
Under tongue-and-groove slabs, you can use a strip of bituminous felt or cork with a density of 250-300 kg / m³. The strip width is slightly less than the width of the blocks. It is laid on a leveled base on the same binder that you will use to seal the joints between the plates. The solution is applied to the surface treated with concrete contact (after drying) with a layer of 2-3 mm. Lay the tape, rolling it with a roller, expelling air bubbles. The emerging solution is removed with a spatula. Thus, the tape is glued to the floor, walls, ceiling. Horizontalness is checked using a bubble level.
Preparation of plates for installation
If silicate tongue-and-groove boards are used, no preparation is required – their upper and lower surfaces do not have a groove / ridge. They are absolutely even (as in the photo below).
When working with a gypsum tongue-and-groove, first you need to decide whether you will place the blocks with a spike or a groove up. It is more convenient to work when the groove is directed upwards, but the opposite position is not a mistake either.
If you decide to put the GWP up with a groove, you need to cut the spike on all blocks of the first row. The easiest way to do this is with a hacksaw. The resulting cut is uneven. We level it with a planer.
Note! The cut of the plate must be absolutely even. It depends on how strong the wall of tongue-and-groove plates will stand. And the trimmed tongue-and-groove plates should be of the same height.
The seam between the blocks does not exceed 2 mm, so even small deviations are almost impossible to correct. Therefore, we align carefully and carefully. After leveling, the dust is swept with a brush and you can begin to build a wall.
First row
The sequence of actions when laying a wall of tongue-and-groove slabs is simple and very similar to a brick one. There are only a few features. Since the partition usually adjoins the wall, if a spike turns out to be turned to it, it is cut off with a saw, the surface is leveled with a planer, and dust is removed. Next, the procedure is as follows:
- A layer of mortar is applied to the wall and base (or the laid vibration damping tape) with a length slightly greater than the length / height of the block. Putting a large layer is not worth it – it will still squeeze out.
- The plate is installed, leveled, with the help of a rubber mallet they are upset and moved close to the wall. Once again control the verticality / horizontality. The squeezed solution is picked up with a spatula.
Make a diversion of the pier with bandaging of the rows - A solution is applied to the end of the installed plate, it is also laid on the base – a little more than the length of the plate.
- Place the next block. With a mallet they “push” it to the already established one, achieving tight contact. By controlling the position with the help of a level, they are upset, achieving the same height with an already installed block. The correct installation is controlled by a rule or level, a flat bar. The tool is applied with a flat side to the already installed blocks – there should be no gaps along the entire length.
Thus, the entire row is built. The last slab usually has to be cut. It could be the beginning of a doorway or just the last slab in a row. Its length should be 3-4 mm less than the remaining gap – the seam gap. You should not increase the gap – stability will decrease. For greater confidence, the joint can be reinforced with a metal corner. Two or three corners for each row. It’s enough.
Second and subsequent
The tongue-and-groove slabs are laid with a spacing of seams – like bricks. The shift of the second row can be half or a third of the length. The best option is half. We cut off half of the whole plate, if necessary, cut off the spike, install it. Further laying is no different. The third row again starts with a whole block, the fourth – with a half, etc.
After laying each block, check whether it is correctly positioned. With such block sizes, the error accumulates very quickly. Therefore, we first check each delivered block with a level for verticality / horizontality. and then, applying the bar horizontally, grabbing neighboring blocks and swiping from top to bottom, we look so that there are no gaps. We also check the absence of deviations in the vertical plane.
Angle
If the wall being erected from tongue-and-groove blocks has an outer corner, we start laying from it. To make it easier to work, we create a corner support. It can be a corner with fairly wide shelves or two boards connected at 90°C. We put the structure in place, check the correct installation, temporarily fix it to the ceiling and floor.
At one of the plates, we cut off the side spike, rest its edge against the set stop, align it, setting the direction with a mallet. At the second plate, we also cut off the side spike, apply glue to this edge, join it with the side surface of the installed plate, knock it into tight contact (the diagram in the figure above).
To install the second row, it is necessary to make a cut in the already installed plate under the lower spike of the next block. We take a hacksaw for metal, we make files. Then, using a wall chaser (a tool for working with foam concrete, but it is also useful for laying wiring in the GWP) or any solid tool, we remove the excess, align the groove, making it the same size and shape as the groove. Using a brush or construction vacuum cleaner, remove dust.
We put the second row starting from the other side – so that the seam is on the other side of the corner. We apply a solution to the end of the lower block. We take half of the block, cut off the side spike, install the lower one into the prepared groove (the rightmost diagram in the figure below). He, too, must rest against the established corner. We carefully align the installed tongue-and-groove plates, checking the verticality and the absence of even the slightest deviations.
Branch
It is also necessary to consider a branch from the partition at a right angle. Partitions will be more reliable if they are made with dressing (middle diagram in the figure). All three plates that are installed have a side spike cut off. The joints are coated with adhesive, three blocks are adjusted close to each other with a mallet. In this case, it is also necessary to control that the partition is perpendicular – that is, the angle is 90 °.
We build the second row so that the middle of the block is above the junction. To install it, you will also need to make a groove in the protrusions of the lower block. Further, these rows alternate.
There is another way to put a T-shaped partition from a tongue-and-groove – without bandaging. To do this, simply lay out the wall (which in the letter T is the top crossbar). To the finished wall, end-to-end, attach the second partition (left diagram in the figure above). To increase the reliability of the connection, metal reinforced perforated corners are installed at the junction.
Doorway
The doorway in the wall of tongue-and-groove slabs can be made with or without a reinforcing beam. It can be done without a reinforcing beam if the width of the opening does not exceed half the length of the block. So a doorway 900 mm wide can be made without a beam if the ceiling is made of PGP 900 mm long. Moreover, the joint of the plates should be located almost in the middle. A slight offset is allowed (by 10 mm), but that the length of the entire part of the block to the right and left of the opening should not be less than 445 mm.
At the time of installation, before the glue sets, the lintel above the door is reinforced with an emphasis (a board supported by a pole resting on the floor) or a structure assembled from boards as in the right diagram. In this case, first assemble the U-shaped jumper from the boards, fix it with self-tapping screws to the blocks located below (control the horizontality of the jumper). Apply a block, mark how to cut. It turns out two L-shaped blocks of the same or almost the same size. Having applied the solution in the right places, they are installed.
If we use tongue-and-groove slabs 667 mm long, it is obligatory to install a reinforcing beam under the opening of more than 660 mm. For the manufacture of beams, you can use a metal corner, channel, fittings, metal strips of considerable thickness. It is possible to use a dry wooden beam with a thickness of 50 mm or more (pre-treat with an antiseptic). The beam should protrude 400-450 mm beyond the doorway.