PVC window installation technology

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How is the installation of plastic windows; what nuances should be paid attention to during measurements and installation; common mistakes, as well as ways to identify them – we will consider these and other pressing issues in this article.

PVC window installation technology

Why so often there are problems with plastic windows?

Many people think that PVC windows are as good as they are installed. In many ways, this is true. The fact is that the manufacture of plastic windows is carried out using automated systems, and calculations and design are carried out on computers using specialized software. That is why defects in the assembly of translucent PVC structures are extremely rare, and the notorious “human factor” is at the fore. It should be noted that in addition to high-quality installation, it is very important to correctly choose a window system that is best suited for certain conditions. And yet, an incorrectly measured window simply cannot be properly installed..

PVC window installation technology Consequences of poor-quality installation

Installers of window systems work “from production”, it is profitable for them to mount windows quickly, while also saving a little foam and anchors for shabashka. Often, the management of a not very responsible assembly company limits the time for installation, overloading the teams with orders and norms. Therefore, the rules for preparing the opening and the device of a multi-layer assembly seam are rarely followed..

Due to the seasonality of such work, it is difficult for a manufacturing company to prepare and retain qualified personnel in the state, hence the incompetence of measurers and installers.

And another reason for the frequent defects in the installation of plastic windows is the weak state control over the implementation of the relevant regulations. This is despite the fact that they have existed for the installation of PVC window systems since 2003, unlike many other construction technologies that are completely deprived of GOSTs, which are actively used in our country. Unfortunately, legislative acts in the field of technical regulation are voluntary if they are not included in the list of mandatory ones. Practice shows that the worst windows are installed where installation takes place practically without control – in new buildings. Therefore, the only way out for customers for the manufacture and installation of plastic windows is to exert pressure in relation to the measurers, teams of installers and contracting companies in general. Naturally, for this, the owner should know the technology of installing windows..

Features of taking measurements of a plastic window

Inspection of the wall opening by a representative of the contractor is a mandatory stage in the design and subsequent installation of PVC window systems. The on-site meter determines the optimal thermophysical characteristics, dimensions and configuration of products, and the method of their installation. Based on the inspection, an installation diagram (measurement map) is drawn up, indicating the main parameters of the order, which is attached to the installation contract. Most of the firms that manufacture windows offer the customer to sign the so-called approval protocol, which shifts part of the responsibility for designing the products onto him. Therefore, already at this stage of the work, the customer will have to delve into some technological issues, unless, of course, he is ready to completely and completely trust the “professionals”:

  1. Selection of materials from which windows are made (profile, glass unit …).
  2. Linear dimensions of window blocks.
  3. Configuration of products – types of sash opening, the presence of imposts or shtulpas in their designs; cross-section of expansion, connecting, decorative profiles and glazing beads.
  4. Completing the window with certain fittings.
  5. Methods of finishing / restoration of internal and external slopes.
  6. Selecting the type of window sill.
  7. Determination of the type of assembly joints.
  8. Choice of fasteners.
  9. Location of windows in relation to quarters and facade lines.

So how are windows measured correctly? It is quite natural to perceive the desire of some customers to get the maximum light opening, in other words – a “bigger” window. Note that the technology for determining the dimensions of windows is based on modern building codes, sometimes in conflict with our preferences..

PVC window installation technology

The main provisions of these standards relate to the requirements for assembly joints between windows and load-bearing structures. The developers of the current GOST R 52749-2007 recommend using a side gap (from any end surface of the window block to the walls) of 15 mm for windows up to 1200 mm in length; 20 mm – from 1200 to 2200; 25 mm – from 2300 to 3000; 30 mm – from 3000 to 3300 mm. For colored windows the corresponding gap dimensions are 5 mm larger. Such mounting clearances, consider them the minimum permissible, best cope with one of their main tasks – resistance to operational temperature and humidity deformations and possible shrinkage of supporting structures.

In practice, the main limiting factor is the quarter configuration. The situation is especially difficult when replacing wooden windows in old houses, where openings have serious geometric and level deviations. With a window profile height of about 60 mm, only 40 mm can be closed in a quarter, and the remaining 20 should be left for the mosquito net. Therefore, seams of a slightly larger size appear between the windows and the opening than are recommended by the provisions of GOST. If the customer is not ready for several days after dismantling the old window to wait for the completion of the preparation of the opening – it does not matter, the installers will easily close up to 50 mm of the gap, foaming it in stages. The expansion gap can be compensated by strips of rigid sheet insulation, such as extruded polystyrene foam. In special cases, expanders are used – these are special additional profiles, due to which the installation gap is reduced. By the way, they are simply irreplaceable on PVC balcony structures, when it is necessary to approach the window block not with slopes, but with a wall and ceiling, which are insulated and often sheathed with frames.

The window profile must be overlapped by a quarter by at least 20 mm.

In order to correctly inspect the opening, to determine the correct dimensions of the required product, experienced measurers recommend dismantling the slope at several points of the opening, from the inside and outside to check the size of the quarter, as well as its deviation from the vertical and horizontal.

How to choose a window and correctly equip it, we will consider in the following articles. We raised questions about the installation of slopes earlier – DIY window slopes.

How to choose a window and correctly equip it, we will consider in the following articles. We raised questions about the installation of window sills and slopes earlier. — “Installing a window sill on your own — what could be simpler “,” We make slopes on our own “.

Opening preparation

Carrying out work on the installation of windows, you always have to spend some time preparing and restoring the opening. This problem is especially relevant when replacing window blocks in old buildings due to extensive damage to dilapidated structures. In an amicable way, it takes two or three days for a high-quality solution, which is simply impossible in residential premises. Quick-hardening cement-based compounds, polyurethane foam in combination with sheet insulation come to the rescue.

After dismantling the old window, the opening must be freed from moving, crumbling particles, protruding elements of the old internal slopes. All surfaces are cleaned of dust, dirt, oil stains. Loose areas should be fixed by filling with a waterproof binder.

PVC window installation technology

Large voids formed when replacing window blocks, for example, between the rows of facing and bearing brickwork, are sealed with dense insulation, all through holes are foamed.

In addition, it is necessary to remove the build-up of mortar, repair cavities and chips on the inner surfaces of the quarter, exceeding 10 mm in height. Such attention to this section of the opening is due to the fact that a hermetic tape seal will be placed here..

Installation of plastic windows

Positioning and temporary fixing of window blocks

Windows can be installed in a pre-prepared opening, both assembled and with the shutters and double-glazed windows removed. In any case, the window unit must have an installation profile designed for mounting the window sill and ebb.

With the help of a level or a plumb line, the windows are exposed in compliance with the required mounting gaps within the permissible deviations – up to 1.5 mm per meter, but not more than 3 mm for the entire length of the product. The difference in window diagonals should not exceed 8 mm. If the opening does not have a quarter limiting the location of the window block, then it is recommended to install the product at a certain distance from its outer edge – not less than 1/3 of the load-bearing wall thickness. If the wall is heterogeneous, with insulation – in the zone of the insulation layer.

PVC window installation technology

With the help of plastic wedges, the window is fixed in the opening. Such wedges are installed in pairs in the corners of the window block, the thickness is adjusted by moving them relative to each other by several intermeshing teeth. The prefabricated plastic shoe has an air chamber, therefore it is not a cold bridge, like a homemade wooden block, and moreover, it does not deform with changes in temperature and humidity. The recommended wedge width is 100-120 mm. All mounting blocks are removed after fixing the window with fasteners, except for the lower support wedges. It is they who transfer the load to the supporting base, and not the bottom assembly seam.

Attention! If the window has a vertical central bulkhead – impost, then the supporting wedges should be placed directly below it.

Fastening PVC windows

Depending on the design and density of wall materials, the weight and dimensions of the product, the strength of wind loads, the size of the mounting clearances, the optimal type and number of fasteners is selected. To fasten windows to openings, use plastic or metal anchor dowels, construction screws or mounting plates.

Polymer dowels are used for walls made of materials of low strength – lightweight concrete, hollow brick, wood, and also to avoid contact corrosion in aggressive environments. Plastic frame dowels provide good thermal insulation of the connected elements.

Self-tapping screws fasten windows to wooden bases – rough frames, embedded elements, wooden frame racks.

Flexible anchor plates are used for multi-layer wall structures, if there is insulation in the area of ​​the window block, and the attachment point must be moved outside of it.

PVC window installation technology

Metal expansion dowels provide excellent resistance to shear loads in solid mineral substrates such as concrete, solid brick, natural stone.

PVC window installation technology

The length of the fasteners is selected in such a way that the expansion element of the anchor is immersed in the base for at least 40 mm. The diameter of the dowels should not be less than 8 mm.

Fasteners must be located in the range of 150-180 mm from the inner corner of the window block and 120-180 mm on both sides of the impost. If there is no impost connection, then one dowel should be located along the line of the shtulpnaya vestibule of the two doors. The distance between fasteners should not exceed 700 mm for white and 600 mm for tinted windows, therefore, an anchor is almost always placed in the area of ​​the middle of the window side profile.

Through holes are drilled in the pre-determined places in the window frame, so that the heads of the dowels and locking screws are recessed into the rebate of the window profile and can be closed with decorative plugs or caps. Depending on the characteristics of the wall materials, anchor holes are drilled in them or drilled with a perforator in a mixed mode – drilling with a blow.

Attention! The drilling depth of the holes in the walls must be at least 10 mm greater than the length of the anchor part protruding into the base.

Flexible anchor plates are attached to the windows prior to installation in the installation opening. To do this, they are snapped into the grooves outside the plastic profile and screwed to it with screws with a drill, the diameter of which must be at least 5 mm and at least 40 mm long. After fixing the window in the opening, the plates are bent and with the help of plastic expansion dowels with a diameter of 6 mm are attached to the wall.

Attention! Each plate should have two attachment points.

Mounting gap filling technology

According to the current GOSTs, when installing plastic windows, a three-layer system of assembly seams must be used. This design was based on a rather simple idea, which was once implemented by German specialists. The main component of the installation gap is the central layer in the form of polyurethane foam, which has a sound and heat insulating function and must remain dry under all circumstances for correct operation. The inner layer protects the insulation from moisture penetration from the inside of the room, in other words, it is a vapor barrier. Self-adhesive tapes or vapor-proof mastic sealants are used for this. The outer layer is a pre-compressed self-expanding sealing tape (PSUL), which allows moisture to pass from the foam insulation, but is moisture resistant from the outside.

The device of a complex seam begins with the installation of the PSUL on a quarter of the opening, 3-5 millimeters from its edge. Thus, a front mounting gap is formed, the size of which is regulated by the working thickness of the sealing tape compressed by at least 25% – in practice, this is about 3 to 20 mm. In some cases, for example, if a quarter of a brick has joining or other minor irregularities, the tape is glued directly to the window profile.

PVC window installation technology

Attention! The current GOST 2007 in article 5.1.9. allows the embedding of the outer layer with plaster compounds, while the previous standard forbade this, allowing only the use of profile details: strip strips, false quarters, ebb.

Note that the use of an ebb tide is a prerequisite for ensuring reliable protection of the assembly seam from atmospheric moisture. The ebb should extend by 30-40 mm beyond the cladding of the outer walls, noise-suppressing pads can be installed under it.

PVC window installation technology

Further, after the final fixing of the window in the opening using anchors or flexible plates, the assembly joint is filled with a layer of foam. Foaming is carried out with a fully assembled window unit. Please note that expansion gaskets must be installed between the glass unit and the profile..

PVC window installation technology

As we have already said, the central layer, depending on the dimensions and features of the windows, can vary from 15 to 40 millimeters. The foam sealant should be applied in a continuous uniform layer, without the formation of voids, breaks, cracks. That is why, with a large width of the window profile, or if the width of the installation gap is much greater than the standard, polyurethane foam is applied in stages, observing technological breaks for drying the layers. It is recommended to do a test foaming of a small area before filling the joint to determine the expansion of the polyurethane sealant. The foam should not extend beyond the outer plane of the window profile.

Attention! Cutting off excess foam makes the central layer too hygroscopic, so this operation is performed only in extreme cases and only from the inner surface of the assembly seam.

On top of the dried foam insulation, a vapor barrier tape is glued onto the opening or mastic is applied. An important stage in the construction of the inner layer of the assembly seam can be considered the treatment with silicone or acrylic sealants of the mating elements of the window system, such as the facing of the slope, the window sill, as well as the joints of individual window blocks with each other and with stand, pivoting, expansion profiles.

PVC window installation technology

At the end of the installation of windows, the protective film must be removed from the frames and sashes..

The main mistakes when installing plastic windows

The first thing worth paying attention to is the deviation of the details of the installed window unit from the vertical and horizontal lines. Recall that modern standards allow inaccuracies of installation up to 1.5 mm per linear meter or 3 mm for the entire product. The vertical, perhaps, is best checked using a plumb line and a tape measure fixed near the window, measuring the distance from the thread stretched under the weight of the cone to the window profile. When using this method, the dimensions of the product do not matter, because we are able to measure along the entire length of the profile. The horizontalness of the parts can be checked by setting on the vertical profiles of the window, including imposts, control marks using the hydro level and subsequent measurements of the distance from them to the edges of the product. Note that only expensive rack levels make it possible to study deviations more or less qualitatively, but in most cases their length is clearly not enough to understand the general picture..

If there are deviations only vertical or only horizontal, then this means that the box is skewed and has no right angles. The lengths of the diagonals are checked with a tape measure – the maximum allowable difference can be 8 mm.

Next, you should check the window for deformations of the window profiles. For these purposes, along the lines of the outer edges of the window profiles, from corner to corner, pull the cord – the deviations are determined visually. A very common problem is the curvature of the middle of the side profiles towards the center of the window. This happens when the installation is carried out on flexible anchor plates that are not able to contain the pressure of the expanding foam, or if there are no spacers between the glass unit and the profile. The deflection of horizontal profiles occurs for the same reasons..

It is very important to check the correctness of the choice and technology of application of a certain type of fasteners. Very often, installers completely unreasonably prefer to use anchor plates for all occasions, since it is much easier to display a product with their help, moreover, they do not need to remove the sashes and remove the double-glazed windows. You should take the most serious approach to meeting the requirements regarding the number and location of fasteners.

The absence of support blocks under the installation profile (most often under the vertical impost) or the use of homemade wooden wedges instead. As a rule, this error is paired with a more serious one – too small or zero mounting gap at the bottom of the window..

Violation of the technology of the installation of assembly seams is mainly in the too small dimensions of the gaps, the discontinuity of the insulation layers or their absence. The most common mistake can be considered overflowing foam material, which entails deformation of the profiles and the need to cut off excess seal.

A related problem causes the blowing of the joints of the elements of the window system – the window sill, the facing of the slope, the connecting, expansion, turning profiles. This is a banal lack of sealing their joints with self-expanding tapes or acrylic, silicone.

Installers often incorrectly mount connected window units, for example, on glazed balconies. Windows are not located in the same plane – “little book”. It is quite simple to check this, you should pull the cord in front of the front line of the window, from corner to corner, and take measurements with a tape measure.

Also, there are often cases of placing adjacent windows not along one horizontal line, or without reference to the geometry of the facade. For example, this is very important on a bay window, panoramic glazing, where one complex window sill can be used with several window blocks. And again, the water level will come to the rescue, making it possible to put mutually located horizontal marks at a sufficient distance.

Problems arising from errors in the assembly of PVC windows, and how to solve them, we will definitely consider in the following articles.

How to avoid poor-quality installation of plastic windows?

  1. Use the services of a large company, it is better if it is a manufacturer of window systems, and not an intermediary.
  2. Study in detail the technology of installing PVC windows. Knowingly they say: “Aware is then armed”.
  3. Prepare a storage area for materials. Free up space near window openings as much as possible, cover pieces of furniture and household appliances with polyethylene, isolate other rooms, fence off the working area outside.
  4. Discuss all the technological nuances with the measurer, be constantly present during installation – do not forget about the large number of hidden works.
  5. Before and after installing windows, check the integrity of the profiles and glass units, the performance of the fittings.
  6. Do not sign the acceptance certificate for new windows until you check the quality of their installation.
  7. If you still find problems later – blowing, mashing, then feel free to contact the contractor with a request to eliminate the malfunctions. In the vast majority of cases, all problems are promptly solved by the manufacturer.
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