Silicone injection damp proofing: Proofing – Wacker Chemie AG

How to Damp Proof Walls

Damp proofing is the term used to describe a method of treating rising damp in walls as opposed to humidity control, which combats condensation, or waterproofing, which safeguards against penetrating dampness and water infiltration via other sources.

As the title of this guide suggests, it addresses the primary considerations of how to control rising damp in walls.

What is rising damp

Rising damp is the spontaneous ascent of water from wet soils into porous masonry walls via a process called capillarity. The water rises through narrow pores in a masonry wall, despite the counteractive force of gravity. Capillary action is the outcome of two opposing forces:

Cohesion, the attractive forces that hold molecules of water together, and

Adhesion, the electrochemical forces that attract the water molecules to mineral surfaces forming the perimeter of the pores.

The capillarity of a liquid is said to be high when adhesion is greater than cohesion, and vice versa. The point of equilibrium between cohesion and adhesion, combined with the rate of absorption and evaporation, determines the height to which moisture can climb.

In simplistic terms, porous masonry absorbs moisture in a slower but comparable way to that which a sponge soaks up water.

What is a damp proof course

A conventional DPC is a physical waterproof barrier laid along a bed joint at the base of a wall during its construction. Before the Public Health Act of 1875, damp proof courses were not mandatory in all UK buildings. Engineering bricks or overlapping layers of slate formed some of the earliest damp-courses although today, strips of synthetic plastic are the most common type of DPC used in construction.

A crack developing in physical DPC does not form a capillary-pore, and therefore it cannot result in any capillary rise. Accordingly, the failure of a physical damp proof course is more likely to occur from materials that supply a pathway by which moisture can traverse the line of the DPC. Raised ground levels, blocked wall cavities and low-rendered finishes are typical examples of how the effectiveness of a physical damp-course becomes compromised. The first, and often the only, act of damp-proofing is to remove any removable materials that bridge the DPC.

What is DPC injection

Installing a chemical damp-proof-course involves injecting a silicone-based formulation into a series of holes formed along the base of a wall that is suffering from the effects of rising damp.

Contrary to common belief, a chemical DPC does not create an impervious physical barrier. Instead, chemical damp-proofing is an effective method of lining the pores along a stretch of a masonry wall with a water repellent silicone resin. The silicone-lined pores neutralise the charge attraction of the masonry particles to the water molecules, thus reducing adhesive attraction to a level compatible with the cohesive force of the liquid.

The damp-proof injection method is one of the main aspects of treating rising damp in houses. It is also one of the easiest, allowing trade specialists, builders and competent DIY enthusiasts to install a remedial DPC reliably.

Where should chemical damp proofing be installed

Introducing a chemical DPC system into the bricks or blocks along a stretch of brickwork will not stop the water rising through the perp-end joints. The mortar presents the only continuous passage ascending a wall through which water can climb. Therefore, a mortar bed joint is the only layer able to function as a damp proof course.

Following BS 6576:2005+A1:2012 ‘Code of practice for diagnosis of rising damp in walls of buildings and installation of chemical damp-proof courses’, a DPC should be sited at least 150mm above external ground level and internally beneath ground floor joists, or close to the floor if solid. If the two are incompatible, added measures may be needed to protect low-lying areas and flooring timbers.

Where a wall extends beyond the new DPC, for example, where the wall is part of an extended terrace, there is a need for a vertical upstand to stop horizontal transmission of moisture from adjoining walls. To form a vertical DPC, inject the chemical into holes running in a zigzag pattern that follows the mortar line up the wall to a height of at least 1 metre.

The cream can be injected from either side of the wall, though for cavity walled brickwork, we recommend injection from both sides. It is unlikely that damp proofing chemicals will prove functional in rubble-filled walls, which are effectively cavity walls filled with rubble. The use of an electro-osmotic system in such instances is likely to deliver better results.

Which type of chemical DPC is most effective against rising damp

For more than a decade, low-pressure damp proof creams have replaced high-pressure injection fluids as the silicon-based chemical of choice for damp-proofing walls. The early chemical damp proof creams have between 10-60% active ingredients, relying on thickening agents to produce a workable cream with a pasty viscosity.

BBA Approved ‘Damp-Cure’ DPC cream is a silane/siloxane formulation thickened by emulsification to create a 100% active cream with no thickening agents. This composition allows the cream to diffuse more effectively into the capillary pores of masonry walls.

Dispensing sufficient DPC cream to fill holes that are 90% the depth of the wall, and set apart at 100-120mm intervals, ensures adequate dosage for an effective rising damp treatment.

Why replace wall-plaster after a chemical DPC injection

Water drawn up from underlying soils and rocks holds dissolved salts. As the saline liquid evaporates, generally over a 6 to 12 month period, crystallised salts remain both in the wall and in its plastered surface.

The accumulation of salt crystals degrades the masonry, mortar and the wall plaster. As salts are typically hygroscopic, they absorb moisture from the air, especially under humid conditions. This salt damp alone can cause the wall and any contacting decorations to remain damp even after the provision of a new DPC.

To comply with BS 6576 fully:2005+A1:2012, replacing salt contaminated wall plaster with a salt resisting plaster mix is an essential requirement in the treatment of rising damp. At least 14 days should elapse between injection of the DPC and the application of new plaster unless using an air-gap membrane to isolate brickwork and salts from the plaster finishes during the drying process.

Rising Damp Treatment – Damp Proof Injection

This DPC injection video shows how to inject damp-proofing cream to stop capillary dampness in masonry walls. Injection of the silicone-based damp-proofing cream is into a series of 12mm holes drilled into the bed-joint utilising a simple injection applicator. The injected DPC cream diffuses rapidly before curing to form a water-repellent damp proof course that treats rising damp in brick and masonry walls.

45 seconds

Damp Proof Injection | Damp Proofing Course Solutions

Home / Property Preservation / Damp Proof Injection

Posted May 12, 2020
|
in Property Preservation

Damp proof injection is a fast, cost-efficient and highly effective form of rising damp treatment. It is commonly used as a remedial damp proof course on buildings where the existing DPC has failed due to age or deterioration. DPC injection is designed to seep into the brickwork in order to prevent moisture from the ground rising up through the bricks by capillary action and causing rising damp.

What is a Damp Proof Course?

A Damp Proof Course, or DPC for short, is a barrier that stops damp from the ground rising up into a building. There are two main types of DPC: membrane damp proofing and chemical damp proofing.

Membrane damp proofing is essentially an impervious barrier which is laid along the bottom brickwork at least 150mm above the ground level during the construction of a house. Chemical damp proofing is usually a remedial DPC, meaning it is introduced by damp proofing specialists when the original DPC fails.

Damp proof injection refers to the installation of chemical damp proofing along the base of the walls of a building that is suffering from rising damp. While it does not form a physical barrier like membrane damp proofing, it lines the pores of the masonry wall with a silicone resin water repellent.

How Do Damp Proof Injection Creams Work?

Damp proof creams are scientifically formulated to penetrate deep inside the building material. They have a consistency that allows the active ingredient, silane, to be absorbed into the substrate both vertically and horizontally without running out. The silane then lines the capillaries before curing to create a water repellent barrier.

The type of chemical damp proof course that should be used is dependent on the wall construction and aqueous based fluid DPC’s may be injected by using high-pressure and low-pressure techniques instead of using DPC creams. Chemical injection DPC is usually used for brick or stone buildings, and our experienced surveyors know exactly how to recommend the most suitable remedial action.

Damp Proof Treatment Using Injections

After our initial survey, our technicians will get to work preparing the affected area both internally and externally before the damp injection begins. This may involve removing fixtures and fittings such as skirting boards and radiators to provide access.

If your property is suffering from rising damp, then any salt contaminated plaster will need removed before injecting a damp proof course. Plaster is usually removed to a height of no less than one metre to remove the salt affected plaster prior to injecting the chemical DPC.

Small holes (around 12mm) will then be drilled horizontally into the wall mortar joint to a depth of around 20 – 30mm from the full thickness of the wall, and the damp proof course will be injected into the boreholes. Left in the wall, the injected chemicals will penetrate the masonry surrounding the borehole. The cream then gets to work creating a water-repelling barrier.

After the damp proof injection, our team will re-plaster internally. Our specific re-plastering materials will ensure that any residual salts in the masonry do not affect the new plaster. This chemical damp proofing solution will provide you with a minimum of 30 years of damp free walls in your property, with the issue of our 30 year guarantee for your peace of mind and also the work can be backed up by the independent GPI guarantee insurance scheme if required.

Damp Survey

When damp appears in your property, you need an experienced damp specialist to accurately diagnose the cause of the problem and provide the most appropriate repair specification. Failure to properly diagnose a damp related problem can result in unnecessary repairs and further costly damage.

Our Surveyors are qualified to CSRT standard (Certificate Surveyor in Remedial Treatment) and experienced in all types of damp issues that could affect your property. With over 85 years’ experience in property preservation, we have the experience and knowledge to tackle any property damp problem you might have, with industry-leading guarantees that are backed up by protection insurance schemes.

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Injection waterproofing: works, materials, prices

Injection waterproofing: how and where to apply

Injection waterproofing is a new technology that is widely used to strengthen and insulate the foundations of new buildings and existing construction projects. An effective way to create a reliable waterproof membrane between structures and aggressive environments.

In the article we will consider the waterproofing of objects by the injection method, the features of the technology, how the work is done, what is required for them, as well as its advantages and disadvantages.

What is injection waterproofing?

Injectable waterproofing is a waterproofing based on liquid polymers, pumped under pressure and works directly inside the building structure or in specially organized sections provided to minimize the consumption of the injection composition and the possibility of localizing leakage.

After entering the structure, helium polymer compositions polymerize, as a rule, within an hour, after which they acquire the ability to withstand very high pressure of the environment.

Application

The method of injection waterproofing has long been used in foreign countries. In Russia, this unique technology has appeared recently, but has already gained popularity in the construction and repair industry.

This technique involves pumping waterproofing compounds into the foundation material and other building elements that are subject to destruction under the influence of a humid environment. For insulation work, special materials and equipment will be required.

The main purpose of injection waterproofing is to strengthen and protect the foundation from destruction provoked by a humid environment. This method is relevant for increasing the bearing capacity of the foundation, for fixing the soil and sealing the formed cracks.

Modern technology is also used to eliminate the inflow of water formed in the foundation, and to equip the cut-off waterproofing between the foundation and the wall of the building.

Technology

Injection waterproofing is performed using a special technology. All materials used remain liquid for 30-40 minutes. Their hardening is regulated by the catalysts included in the composition. Experts recommend that work be carried out at a temperature not lower than 5 degrees.

Waterproofing injection methods

The choice of injection waterproofing technique depends on the selected material and the surface to be isolated.

Where the technology is applied:

For foundation injection. The best option is the use of a cement-sand composition based on silicates.
For waterproofing walls during the construction phase and during major repairs. It is recommended to use acrylic or polyurethane material.
For grouting basements and basements.
In order to strengthen the base of concrete structures, waterproofing of joints and cracks is carried out.
To improve the quality of a brick building, waterproofing is carried out by injection using hydrophobic compounds.
For strengthening old foundations and restoring bearing capacity.
For sealing cold joints in reinforced concrete structures, etc.

Methods for applying injection waterproofing:

“Gravity” – involves filling holes drilled at an angle with material and its subsequent movement under the action of gravity. When performing insulation by this method, fast-hardening compounds cannot be used.
“Under pressure” – filling of materials occurs under a pressure impulse. The pressure supply is provided by a pressure pump. It is possible to carry out work on this technology only in warm weather (not lower than 5 degrees Celsius).

Equipment for injection waterproofing

To carry out waterproofing work using the injection method, you will need a special metal packer and a high-pressure pump.

Materials

Injection waterproofing of the foundation and other building surfaces is carried out using various materials.

What materials can be used:

Polyurethane polymer is a highly plastic material that can withstand various loads well. Economic consumption. Affordable cost. It is widely used to isolate foundations located on the territory of quicksand and loose soil.
Acrylic gel is a strong and resistant material. Easily penetrates into the smallest pores of the foundation. Hardens quickly. Soil particles are used to strengthen the material, which provides additional protection against washout.
Epoxy material – used in dry construction. Hardens quickly on contact with air. After complete polymerization, the solid membrane becomes completely impermeable to water.
Materials based on siloxanes or silicates. When interacting with the main building material, they are converted into an emulsion that creates a highly effective barrier to water. Can be used for waterproofing surfaces with high humidity.

Work steps

Waterproofing works by the injection method are carried out in stages, in accordance with important technological rules.

Stages:

Examination of the surface to identify points of localization of moisture penetration.
Drilling through holes in increments of up to 0.5 m. Diameter – up to 20 mm. Additional holes are made in places of localization.
Drilling blind holes along a fault line or cracks.
Metal packers are inserted into the created holes, ball valves are fixed to their outer part.
A tank with a waterproofing compound is connected to the ends of the fixed taps.
The composition is transported through the tube by gravity or under the influence of pressure (depending on the chosen method of injection).
After the material has hardened, the tubes are removed.
The outer surface is covered with a layer of moisture-resistant plaster or cement-sand mortar.

Advantages and disadvantages

Injection waterproofing has many advantages. This technique eliminates the need for earthworks when strengthening the foundation of ready-made buildings. The mixtures used do not contain harmful impurities, therefore they are absolutely safe for the human body.

Due to the low density of the compositions, a high penetrating ability of the material is ensured. When carrying out work, it is not necessary to carry out preliminary drying, injection gels have good adhesion to wet surfaces. Waterproofing can be performed even in cold weather, the main thing is to choose the appropriate material adapted to low temperatures.

Other advantages of injection waterproofing:

work can be carried out during the construction phase and after the construction of the building;
technology is used for overhaul;
the result is a guaranteed quality waterproofing with a reliable membrane that envelops the entire surface.

The disadvantages of injection waterproofing include the high cost of materials, the need to use special equipment and the mandatory observance of technological rules. In the absence of skills, it is better to entrust this work to specialists.

Features of injection of various designs

Injection waterproofing is carried out according to the standard scheme, but has some features when performing work on different construction sites.

To improve the performance of the erected building, walls are injected. Works are carried out at the construction stage or during the overhaul.

When the foundation is injected, vertical waterproofing is performed with the creation of a horizontal barrier that prevents the penetration of moisture.

External and internal waterproofing is carried out when injecting basements.

To strengthen the foundations of concrete structures, waterproofing of cold and moving joints is carried out.

To increase the strength and moisture resistance of brick buildings, insulation is made using hydrophobic compounds.

To date, high-quality injection waterproofing is performed by specially trained craftsmen who have all the necessary equipment in their arsenal.

Injectable waterproofing

The purpose of waterproofing a building and structure is to maintain the strength of the foundation, and, consequently, of the entire structure as a whole, extending its service life and minimizing possible repair costs.

Usually a protective waterproofing layer is created during the construction process. But, it often happens when the owner of the premises acquires it in the state when you have to think about updating the waterproofing. What to do in this case?

The most promising option is to expose the foundation and re-engage in the creation of a protective layer.

The method of such work is always chosen individually, based on the characteristics of the building and the causes of insulation failure. Applying a new waterproofing material to the foundation is not so difficult and costly as it seems. But, here the manipulations with the soil require large time and financial investments. And the subsequent need to improve the territory makes the project even more expensive.

The way out of this situation is the method of injection waterproofing. It gained great popularity in the countries of Western Europe, where they learned to protect buildings from water and moisture at any time of the year. Moreover, this method allows you to work indoors.

Work technology

Before the start of waterproofing work by injection, an inspection of the object is carried out and a detailed plan of the necessary operations is drawn up. This work must be entrusted to experienced specialists who will correctly identify the problem by determining what substance is required to treat the underground part of the structure, and calculate the volume of polymers.

Depending on the density of concrete and the goal, the type of composition of the injection solution is determined. In this case, the introduction of injection polymers can be carried out directly into the body of the building structure, as well as into seams, cracks in the foundation. If necessary, the solution is also supplied behind the structure of the structure, thereby creating a protective screen. If you do a complete waterproofing of the object, you will need a large amount of solution. It will be more economical to fill them with only cracks and seams. However, the possibility of this should be determined by specialists.

The waterproofing plan must have a diagram indicating the number and location of holes, each of which has its own number. Holes, or small holes, are drilled in a checkerboard pattern in increments of 25-30 cm. Their depth should be approximately 70% of the wall thickness. Through holes are drilled only to create a waterproofing filter surfaces.

To restore the waterproofing of the horizontal layer, the holes are made in two rows at the level of the beginning of the wall. In the holes obtained, parquets are attached, through which an injection solution is injected using special equipment capable of creating a pressure of 250 atmospheres. Then all accessories are removed, and the surface of the wall and foundation is cleaned of excess mortar. The next stage of finishing work is recommended to begin with covering the restored area with a special sealant. This will make it possible to level the traces of repair and improve the hydroprotection of the surface of the material.

Types of injectables

Today, a variety of innovative compounds are used to create injection waterproofing, and their list is constantly updated. But, the most popular are polymer solutions.

Depending on their chemical composition, they can have different elasticity, porosity, the ability to increase in volume and polymerize. The ability of polymer solutions to fill microcracks and other voids is based on the property of polyurethane to expand several tens of times under the influence of moisture. In addition, such compositions are well retained on the surface of almost all types of materials.

Polyurethane injection solutions are used for:

fix stubborn leaks;
insulation of working seams and damaged structural butt joints;
horizontal waterproofing;
filling voids in the foundation;
foundation strengthening;
structural reinforcement.

To repair materials with a finely porous structure, as well as to eliminate cracks and protect the separating layers of the foundation from water, epoxy and polyurethane resins are used. They are very strong, have good adhesion to concrete, steel and other materials that may be included in the foundation structure. This resin is not used in working with PVC, polyester and polyethylene. The main purpose of epoxy resins is to strengthen small damaged areas of the waterproofing of an object.

In some cases, instead of polymers, acrylate gels can be used, which can include up to five different components. Acrylates do not have a high degree of viscosity. However, they perfectly penetrate the structure of the material, filling the smallest pores and voids. At the same time, such gels are elastic and ideally fit on building structures. The injected acrylate is in a gel state. It expands and solidifies only upon contact with water. Such an injectable composition is suitable for repairing active leaks, as well as for restoring waterproofing and creating new barriers.

Silicone compounds are used to create waterproofing and strengthen old foundations. They are made of silicone and silicon. Such compounds have high adhesion and well fill micropores, cracks and other voids. It is possible to strengthen the foundation and soil with the help of microcements.

Difficulty of choice

Before starting waterproofing work, the question always arises, which composition and solution is best suited for injection. Only a specialist can answer it correctly. But, the general principles of choice are as follows:

To create masonry waterproofing over large areas, mortars with low viscosity and a long curing period are suitable. At the same time, the composition penetrates better into the brickwork and fills the pores of the building material.
Cold working joints of foundations and walls are recommended to be treated with acrylic gels.
Communications bushings are protected with polymer resins.

In addition to creating an insulating film, cracks can be repaired using injection waterproofing.