How high damp proof course?

Asked by: Alia Hagenes
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A damp-proof course is a barrier, usually formed by a membrane built into the walls of a property, typically 150 mm above ground level, to prevent damp rising through the walls.

Where should a damp proof course be installed?

All damp proof courses must be laid between an even, fresh bed of mortar in continuous lengths for the full width of the wall or leaf and preferably project beyond the finished external face of the external leaf. (including any externally applied render).

Do damp proof courses fail?

In fact, it is one of the biggest causes of rising damp in a building. When a damp proof course fails, it allows moisture to enter bricks and mortar. ... A damp proof course, even a properly-installed one, may only last for about 20-25 years. An incorrectly installed DPC likely won't last this long.

What is the specification for damp proof course?

Properties of Materials for DPC

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. It should be free from deliquescent salts like sulfates, chlorides, and nitrates.

36 related questions found

How damp proofing is done?

A damp-proof course (DPC) is a barrier which can be inserted through a structure above ground level to stop capillary action which is damp rising from the ground. ... Integral damp proofing in concrete involves adding water proofers to the concrete mix to make the concrete itself moisture resistant.

What is the best damp proof course?

The Best Damp Course Injections
  • Dryzone Damp Proofing Kit.
  • Dryzone DPC Cream (cream only)
  • Rempro Damp Injection Cream Kit and Installation Guide.
  • Rempro DPC Injection Cream.
  • DryFix DPC Damp Proofing Injection Cream.

Can you sell a house with rising damp?

Can a house with serious damp issues be sold? The simple answer is 'yes', but it depends on the price you want to sell for. ... In severe cases of rising damp, mortgage companies won't lend and that means the seller will either need to carry out the work themselves or sell to a cash buyer.

How do I know if my damp course failed?

What are the signs of a faulty damp proof course?
  1. 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.
  2. Damaged skirting boards.
  3. Peeling wallpaper.
  4. Salt deposits on wall.
  5. Blistering or peeling paint.

Do all houses have a damp proof course?

The vast majority of properties have been built with a DPC. This is designed to stop moisture from penetrating up past that point. Initially materials such as slate were used, which as we all know has been in existence for thousands of years.

Can I do damp proofing myself?

Twistfix supplies its DIY damp proofing kit with everything needed for a do it yourself damp proof course to stop damp walls. ... Inject sufficient cream to fill the hole to within 1cm of wall surface and leave it to diffuse through the wall and cure to form a chemical damp proof course.

Does damp proof cream work?

Laboratory tests at its research and development laboratory have proven that DPC creams with low concentrations of silicone will ultimately prove ineffective. DPC creams work because they contain silicone that penetrates the pores of the mortar in masonry and brickwork to form a waterproof seal.

How do I install a damp proof course?

How to Install a Damp Proof Course
  1. Drill 12mm diameter holes at 115mm intervals in the mortar course (or via the brickwork, angled down to meet the mortar course) selected to be at least 150mm above outside or abutting ground level.
  2. Fit the extension nozzle to the cartridge tube and load into the skeleton gun.

Is damp course floor level?

A damp-proof course is a barrier, usually formed by a membrane built into the walls of a property, typically 150 mm above ground level, to prevent damp rising through the walls. ... Continuous with any damp-proof membrane in the floor. At least 150 mm above the level of the adjoining ground if it is in an external wall.

Should air bricks be above or below damp course?

Air bricks may be located either above or below DPC level and where possible on all sides of the building. Ideally air bricks should be located at least 75 mm above hard and soft landscaped areas to reduce the risk of being obstructed or flooded (see diagram 1).

Can DPC be above floor level?

Unlike timber suspended floors where the damp proof course will be sited below floor level with solid constructed floors the DPC should always be sited above finished floor level and should be visible.

How do I know if I've got rising damp?

Signs of rising damp include a tide mark on walls - usually no more than a metre above floor level - rotting or crumbling skirting boards, rotting floorboards and salt deposits on internal walls.

How often should damp proofing be done?

Typically, a physical damp proof course lasts for 20-25 years and can fail due to it not being fitted properly or deterioration. If a damp proofing course has failed then this could potentially lead to rising damp.

How much does rising damp treatment cost?

For rising damp treatment, a damp proof course is needed which will cost around £280 to £400 for a typical terraced home. This is usually installed in your front interior walls and should take around 2 days to complete.

Can I paint over rising damp?

Never paint over damp – it doesn't address the root cause of bubbling paint or peeling wallpaper, and you'll need to paint it again very soon. Fix the source of the damp then let the wall fully dry out before painting it.

Is rising damp easy to fix?

How do you fix rising damp? The only way to treat rising damp is to create a new damp-proofing course to prevent moisture movement through the structure. Historically, walls were cut into and masonry removed to install a new physical damp-proofing course along the masonry line.

Does rising damp dry out?

In severe cases Rising damp can be identified by a characteristic “tide mark”. This mark is found on the lower section of affected walls where the rising damp is drying out through the plaster. Rising damp also brings nitrate and chloride salts up from the ground.

How do you treat rising damp in an old house?

Treatments for rising damp include:
  1. A chemical DPC injection.
  2. Replacement of rotting joists or internal flooring which has come into contact with damp.
  3. Removing and replacing damaged interior plaster.
  4. Bridged DPC – requiring the removal of bridging materials or soil to enable a minimum of 150mm clearance below the DPC.

How much does it cost to inject damp proof course?

The costs of a professional DPC injection will vary between areas and suppliers. But, as a rough guide, £70 per metre of wall treated is an average. This represents a cost of £275-£300 per wall.

Can damp proofing be done from outside?

Damp proofing can be done from outside of a building. In fact, in most cases it is the easiest way to damp proof a property. Whether the property has had damp for years or you have caught it early, damp proofing the outside is a great way of keeping the damp out.