where is the damp proof course

Full Answer

Why is a damp proofing course so important?

A damp proof course is a preventative measure that can be taken to prevent damp from causing any problems in the future. This can be a barrier made from bitumen, slate or plastic and built into the walls of the property, just above ground level. This will help to prevent damp from rising up through your walls.

What is damp proof course DPC and its properties?

Property owners want damp proof courses on their properties. By installing the DPC, moisture that rises from the ground is prevented from getting into the property. Where Should Dpc Be Installed? Basement walls and floors are usually sealed with damp proof courses, in the hopes of reducing moisture’s movement. What Is The Purpose Of The Dpc?

How much does damp proofing cost?

You’ll find contractors offer free damp survey and then who remove the survey fee once the work is carried out. If they use a local professional, CSRT qualified, but non-independent surveyor, services will range from £50-£120. Of course, there are plenty of excellent companies that work this way.

Can I cover the damp course?

The worse a damp situation gets, the more it’s likely to cost to repair any damage. Most standard buildings and contents home insurance policies do not cover damage caused by damp and condensation. A damp-proof course can run into thousands of pounds if the whole house needs treating.

How do you know where the damp proof course is?

You can find your DPC by taking a look at the external wall. Look down at ground level and look up about 6 inches or so up the wall. Somewhere around here you will see a thin black line of either slate or plastic running horizontally across the brick work. This is your DPC.

What does a damp course look like?

The most common type is the physical and visible DPC, often a type of thin waterproof material such as lead-lined bitumen, slate or plastic. These DPCs look like fine sheets of material situated between the brickwork of a building near ground level and can also be referred to as damp proof membranes.

What is a damp proof course on a house?

The damp proof course prevents damp from the ground rising up the walls and damaging your property. Properties which have no appropriate damp protection layer or has a damaged damp course may be affected by excess moisture rising from the ground.

Do all houses have a damp proof course?

Although building regulations require the inclusion of a damp proof course in any new building, they do not specify one single material. It may be built from 'bituminous material, polyethylene, engineering bricks or slates in cement mortar or any other material that will prevent the passage of moisture. '

Do old houses have DPC?

A Damp Proof Course (DPC) is an impervious layer built into a wall. It is placed above ground level to prevent moisture rising up the wall via a capillary action. Older buildings used a range of materials for a DPC, including slate, bitumen, jute and hessian. Nowadays plastic DPCs or chemical injection DPCs are used.

Does home insurance cover damp proof?

The worse a damp situation gets, the more it's likely to cost to repair any damage. Most standard buildings and contents home insurance policies do not cover damage caused by damp and condensation. A damp-proof course can run into thousands of pounds if the whole house needs treating.

Who is responsible for damp proof course?

landlordIf there's a problem with an existing damp-proof course (DPC) in your home which is causing the damp, then your landlord is likely to be responsible for repairing it. If your home doesn't have a DPC, your landlord may not be responsible for putting one in.

How long does a damp course last?

Damp course injection is a long-lasting solution to damp problems. Once installed, damp proof injections should remain effective for the at least the period of the provided guarantee, which in our case is 30 years.

How do you know if you need a new damp course?

Signs That You Need a Damp-Proof Course Black spot mould forming on interior walls. This is a common sign also of a condensation problem. Watermarks on walls formed by either rising damp or penetrating damp. Plaster peeling off walls and damage to other decorative finishes such as wallpaper.

How do you know if your damp proof course has failed?

A damp tide mark, typically up to 1.5m high on your inner wall, external wall, or both caused by groundwater gradually rising through the porous surface of your brickwork. Damaged skirting boards. Peeling wallpaper.

How do you fix a damp course?

The most common and effective way to treat rising damp is to install a remedial damp proof course by injecting a water repellent damp proof cream into the mortar bed joint of affected walls.

Should you see a damp course?

The damp proof course may not be visible because of the external render which if correctly finished should stop at the dpc level and not go below it. If you are unsure that it is there it should be very easy for your builder to show you.

What is the choice of material to function as an effective damp proof course?

The choice of material to function as an effective damp proof course requires a judicious selection. It depends upon the climate and atmospheric conditions, nature of the structure, and the situation where DPC is to be provided.

What are the properties of damp proofing material?

Properties of Materials for DPC. An effective damp proofing material should have the following properties; It should be impervious. It should be strong and durable and should be capable of withstanding both dead as well as live loads without damage. It should be dimensionally stable.

What is DPC material?

DPC Material for floors, roofs etc. For greater wall thickness or where DPC is to be laid over large areas such as floors, roofs, etc., the choice is limited to flexible materials that provide a lesser number of joints like mastic, asphalt, bitumen felts, plastic sheets, etc.

What type of concrete is used for DPC?

For DPC above ground level with wall thickness generally not exceeding 40 cm, any one of the types of materials mentioned above may be used. Cement concrete is however, commonly adopted material for DPC at plinth level, 38 to 50mm thick layer of cement concrete M15 (1:2:4 mix) serves the purpose under normal conditions.

What should a DPC cover?

The DPC should cover the full thickness of the walls, excluding rendering. The mortar bed upon which the DPC is to be laid should be made level, even and free from projections. Uneven base is likely to cause damage to DPC.

What is damp proofing membrane?

In membrane damp proofing, a water repellent membrane is inserted between the source of dampness and the part of the building adjacent to it. Damp proofing material may be like bitumen, mastic asphalt, polythene sheets, bituminous felt, metal sheets, cement concrete, etc. damp proofing course may be provided either horizontally or vertically in floors and walls.

What is the best material for damp proofing?

Common damp proofing materials: 1 Hot bitumen: Highly flexible hot bitumen is placed on the bedding of concrete or mortars with a minimum thickness of 3 mm. 2 Mastic Asphalt: Mastic Asphalt is obtained by heating Asphalt with sand and mineral fillers up to standard temperature. It is semi-rigid material of good property of impervious and durable. Which is also able to withstand very hot climate heavy pressure.

Why is dampness important in building design?

Dampness not only reduces the strength of the structural components but also gives rise to unhygienic conditions. So, in the building design, damp prevention is one of the important factors to be considered, and every building Should be damp proof. So, “ damp-proofing ” or “damp proof courses ...

How does moisture enter a building?

If the foundation soil on which substructure is is embedded is previous, moisture slowly and constantly travels through the structures founded on the soil. There is also a lot of moisture present in the impervious soils. By the capillary action, this moisture may rise into the floor through the wall. This process of rising groundwater I will also so slowly result in moisture entry into the building.

How does a cavity wall protect against water?

The cavity wall prevents the protection of water inside the building by shielding the main wall by an outer skin wall living a cavity between the two. It is an effective damp proofing technique.

How is mastic asphalt obtained?

Mastic Asphalt: Mastic Asphalt is obtained by heating Asphalt with sand and mineral fillers up to standard temperature. It is semi-rigid material of good property of impervious and durable. Which is also able to withstand very hot climate heavy pressure.

Why do walls and ceilings get damp?

Due to much decrease in atmospheric temperature, there is a condensation of atmospheric moisture that causes deposition of water on the walls, floors, and ceilings. This moisture may cause dampness.

What is damp proofing?

Damp proofing is accomplished several ways including: A damp-proof course (DPC) is a barrier through the structure designed to prevent moisture rising by capillary action such as through a phenomenon known as rising damp. Rising damp is the effect of water rising from the ground into property. The damp proof course may be horizontal or vertical.

What is damp proofing in construction?

Damp proofing or a Damp-Proof in construction is a type of moisture control applied to building walls and floors to prevent moisture from passing into the interior spaces. Dampness problems are among the most frequent problems encountered in residences.

What is a vertical vapor barrier?

Concrete normally allows moisture to pass through so a vertical vapor barrier is needed. Barriers may be a coating or membrane applied to the exterior of the concrete. The coating may be asphalt, asphalt emulsion, a thinned asphalt called cutback asphalt, or an elastomer. Membranes are rubberized asphalt or EPDM rubber. Rubberized products perform better because concrete sometimes develops cracks and the barrier does not crack with the concrete.

What is a DPC layer?

A DPC layer is usually laid below all masonry walls, regardless if the wall is a load bearing wall or a partition wall. A damp-proof membrane (DPM) is a membrane material applied to prevent moisture transmission. A common example is polyethylene sheeting laid under a concrete slab to prevent the concrete from gaining moisture through capillary ...

Where is the DPC in a cavity wall?

In a masonry cavity wall, there is usually a DPC in both the outer and inner wall.

What materials prevent damp?

The later application of impermeable materials which prevent the natural dispersion of damp, such as tile, linoleum, cement and gypsum -based materials and synthetic paints is thought by some to be the most significant cause of damp problems in older buildings.

What are the different types of dampness?

There are many solutions for dealing with dampness in existing buildings, the choice of which will largely be determined by the types of dampness that are affecting the building, e.g., rising damp, hygroscopic damp, condensation, penetrating damp, etc.

When was damp proof course required?

A damp-proof course is a standard element which is required when building a property. Damp-Proof Coursing was made compulsory in 1875, however many DPC’s installed in the immediate period after this were laid shoddily and no longer fulfil their purpose. Initially DPCs consisted of slate or lead barriers, fitted into the walls to protect ...

How high should a damp proof course be?

Most properties which exist today should have a damp-proof course which is evident at a minimum of 150 mm above ground level. This may appear as a mortar course with a bitumen or plastic DPC sheet poking through. These materials tend to be very effective, unless the building movement result in them cracking or the DPC is bridged or the older bitumen material breaks down due to old age. Damp-proof courses are required in all new build properties in order to prevent rising damp from occurring.

What is Damp Proof Course (DPC)?

It is immensely important for all property owners to ensure that their property is protected with an effective damp proof course.

What Causes Damp Walls?

The most important step with regards to fixing your properties damp walls is identifying the cause of your damp problem. In order to do this, you need to ensure you have carried out the appropriate inspection of your property both internally and externally. However, to the untrained eye it can be very difficult to accurately identify the source of your damp issue. For this reason, we would always recommend the use of a damp proofing specialist who will save you time and money by providing you with an accurate diagnosis of the source of the problem and the appropriated action required to resolve the damp issue.

What is damp proofing?

The damp proof course prevents damp from the ground rising up the walls and damaging your property. Properties which have no appropriate damp protection layer or has a damaged damp course may be affected by excess moisture rising from the ground. This excess moisture can affect plaster, decoration and can even result in wet rot, ...

What is a mortar injection course?

Mortar Injection Damp Proof Course – This is similar to the use of creams or liquid injected into the wall. Instead of cream or liquid being used a chemical enhanced mortar is used and caulked into the holes drilled in the wall. This is used where the construction of the wall may be of random rubble and are prone to having voids within the structure. The mortar fills the hole in the masonry and the chemical is drawn from the mortar into the wall structure to block the rising damp.

How to tell if a wall is damp?

If you suspect that your wall is affected by damp then you should inspect the outside and inside off your property looking for defects that could cause damp to affect your wall. You could then use a moisture meter which will tell you if the wall has a higher moisture content than it normally should be.

What is damp proof course?

It is a barrier or obstruction that is primarily designed to prevent the moisture rising by the capillary action. The capillary action through which the moisture rises is known as the rising damp.

What are the desirable properties of damp proofing?

The desirable properties of the materials used for the damp proof course can be listed as follows: a. The material used for the damp proof course must be impervious i.e. it must prevent the passage of moisture through it . b. The material must be strong as well as durable.

What is surface treatment?

Surface treatment includes the method of laying a water repellant layer or water-resistant substance on the surface through which dampness is likely to occur . It is the most common method of damp proofing when the moisture or dampness occurs superficially.

What are the factors to be considered during the construction of a DPC?

Some of the factors that must be considered during the construction of the damp proof course are as follows: a. Before the damp proof course is laid, the mortar upon which it is to be laid must be made level, even and free from any sorts of projections.

How deep does mastic asphalt spread?

When the mixture is hot, the consistency is such that it allows the mixture to spread evenly to a depth of about 2.5cm to 5cm. Upon cooling, the mixture sets. However, special care must be taken while laying the mastic asphalt as the damp proof course. b.

What is the most common material used in DPC?

Rich Concrete is the most commonly used material in DPC. Usually, rich concrete in the proportion 1:2:4 that is painted with two relative coats of hot bitumen is used for the horizontal damp proof course. It is suitable for the portions of the building or structure that are not subjected to excessive damping.

How many layers of stone are there in a DPC?

Two layers of stones are laid in lime, cement and sand mortar (1 lime :1 cement : 6 sand) which acts as DPC.

What is damp proof course?

The damp proof course (DPC) is generally applied at basement levels, which restricts the movement of moisture through walls and floors. The selection of materials for the damp proof course and its various methods of applications in buildings is discussed.

What is the choice of material to function as an effective damp proof course?

The choice of material to function as an effective damp proof course requires a judicious selection. It depends upon the climate and atmospheric conditions, nature of the structure, and the situation where DPC is to be provided.

What type of concrete is used for DPC?

For DPC above ground level with wall thickness generally not exceeding 40 cm, any one of the types of materials mentioned above may be used. Cement concrete is however, commonly adopted material for DPC at plinth level, 38 to 50mm thick layer of cement concrete M15 (1:2:4 mix) serves the purpose under normal conditions.

What material is used for DPC?

For greater wall thickness or where DPC is to be laid over large areas such as floors, roofs, etc., the choice is limited to flexible materials that provide a lesser number of joints like mastic, asphalt, bitumen felts, plastic sheets, etc.

What thickness should a DPC cover?

The DPC should cover the full thickness of the walls, excluding rendering.

What is a Damp Proof Membrane?

A Damp Proof Membrane (DPM) is a material with an effective vapour permeability rating of less than 0.03.

What is damp proofing grout?

Pressure grouting damp-proofing is a technique that fills in the gaps in a material with a liquid grout, usually containing an admixture of cement, water, and an additive such as sand or polymers.

Why are damp proof membranes less common today than they were in the mid-20th century?

External damp-proof membranes are less common today than they were in the mid-20th century because they have been replaced by bituminous or have had their role augmented by it.

Where are free moisture molecules attracted to?

Free moisture molecules are attracted to the buried cathode and repelled from the positively charged anode zone.

Where are copper anodes installed?

At set intervals, the anodes are installed into brick, concrete, or stone walls. The copper cathode is placed at a lower level, at least a meter or two away from the walls.

What is a DPM?

A Damp Proof Membrane (DPM) is a material with an effective vapour permeability rating of less than 0.03.