Plastic mounting wedges

Recommendation points

• What are mounting wedges
• Varieties and features of the device
• Use for leveling the floor on logs
• Installing windows using wedges
• Application of wedges when installing the door

Mounting wedges have appeared in the repair business for a long time, but they have become entrenched in the working arsenal only among real professionals. In this article we will tell you why it is so important and at the same time convenient to use assembly adjusting wedges, and how to use them in various construction and repair work..

What are mounting wedges

Pre-leveling is rarely complete without all kinds of substrates, wood chips or blocks. Using materials at hand is cheap and cheerful, but not always convenient, you have to carefully select the thickness and number of substrates, which over time can dry out and precipitate.

Plastic mounting wedges are free of these disadvantages. Despite their primitive appearance, these devices are an example of well thought out engineering. Wedges are made of plastic, the service life of which is not less than that of the mounted elements.

The wedge has a cross-section in the form of a right-angled triangle, the legs of which are the nomenclature length and height. The surface of the wide edges is ribbed, and the shape of the protrusions is specially selected so that the two folded wedges do not part under load. This is exactly how they are used: at least two wedges form a rectangular leveling block that does not distort the shape of the supporting surface and can be easily adjusted in height by converging and spreading the wedges.

Varieties and features of the device

There are three main standard sizes of wedges, they are called so: small, medium and large, the permissible load is about 200-350, 1500-1700 and 2200-2500 kg, respectively. The wedges can withstand this weight without deformation thanks to the special honeycomb structure and the presence of multiple stiffeners. On the grooved surface, you can see flat and hollow areas, they are mutually located so that when the wedges are brought together and separated, the area of ​​their contact is always as large as possible.

However, the specified loads can withstand the pads only with 100% wedge adhesion; when adjusted, this indicator will decrease in proportion to the contact area. Usually, the wedges of the pads converge by 2/3 of the length, so the real bearing capacity of the pads is 60-70% of the passport.

When the wedges are displaced inside the block, you can hear distinct clicks – this is jumping over the ridges in the grooves. The height of each is strictly normalized, so that in one click, the wedge drops or rises to a certain height. Accordingly, if the height of one wedge in its thickest part is 15 mm, then the adjustment range of the entire block will be from 15 to 20-22 mm with a step of, say, 0.5 mm. If you need a block of greater height, insert a third between the two wedges, increasing the adjustment range by another 15 mm.

Another key feature of wedges is that they can be used in places where it is critical to maintain a continuous insulation contour, for example, in the foam seams of windows. Due to the cellular structure, the wedge does not increase the thermal conductivity of the insulating material. However, the wedges are not without drawbacks, for example, when fastening the floor log, the wedges may shift due to vibration. However, craftsmen always try to carry out through fastening directly through the block, regardless of the presence of dynamic loads..

Use for leveling the floor on logs

One of the obvious ways to use mounting wedges is to level the floor with them. But there is one drawback here: the plastic at the wedges is quite hard, so when you install the block directly on concrete, it will gradually crumble the upper fragile layer and sag.

They do this: first, longitudinal logs are attached along the room or the slope of the floor. Next, the axes of the installation of the transverse lags are marked on them and they are laid by inserting pads from medium or large wedges at the intersections of the beams. Further, the lags can be leveled at least by the rule, at least by the axis builder. After that, each block is covered with a small amount of polyurethane foam on the side to prevent movement during the joining of the lags. After about a day, steel pins or screws are driven into the crosshairs of the lag, or the bars are fastened with metal corners.

This sub-floor leveling method is great for small spaces. The longer the logs, the stronger the twisting of the wood is reflected on the plane of the floor, because it is not possible to press the bars as they level out. Therefore, in wide rooms, logs should be made of laminated veneer lumber.

Installing windows using wedges

Strictly speaking, no other way of installing windows can be used. In the window frame, the load is unevenly distributed and with the pushing of the wooden substrates, the window will twist, the thermal insulation will deteriorate or the fittings will stop working. The greatest load falls on the areas under the imposts, where there must be one block at a time.

Usually, small and medium wedges are used, orienting them along the frame so that a small layer of foam is covered on the sides of the last. There are two installation options: directly under the impost or 100–120 mm on both sides of its center. In the latter case, it is possible to use the mount through the frame for additional fixing of the pads. Installation under an impost is no worse: under static loads, the wedges will not disperse by themselves, and with wind loads, the surrounding foam will not allow them to move.

The optimum thickness of the bottom foam seam is 25–30 mm, for which a height of 2–3 wedges, 80–90% in contact, is sufficient. The frame is first installed on the folded pads, then the upper corners are temporarily fixed, set in a plane, aligned with the vertical level, and only then they begin to mix and dilute the pads. After leveling, the frame is fixed thoroughly and foamed, there is no need to be afraid of accidental shifts and violations. To temporarily fix the window in the opening, wedges or pads can also be used, however, after the foam seam has dried, they must be removed and the voids filled with foam.

Application of wedges when installing the door

Mounting wedges are widely used when installing doors, both entrance and interior. Strictly speaking, the key difference is the number of sides of the vestibule.

Four-sided door blocks (entrance doors), which are installed on mounting wedges, do not require a preparatory tie. The number of blocks is selected depending on the weight of the door block. Typically, for hollow honeycomb doors, two blocks of medium wedges are sufficient, and for steel doors, large wedges should be used. It is very easy to align heavy blocks with wedges: one edge of the threshold is slightly raised with a pry bar and adjusted in level, then a block of wedges is squeezed next to the mount. That’s it, the support will not sag and not corrode, you can start fixing.

Doors with a three-sided rebate are installed with a lining of two leveling blocks under the frame vertical. If the doors are installed on a subfloor, the chocks are assembled from wedges approximately equal in thickness to the finishing coating. The installation pads can be glued in advance, so you can get rid of the trimming of the mullions when laying the flooring.