What are the problems with damp proofing?

Author: Devon Ruecker IV  |  Last update: Tuesday, July 22, 2025

A failed or bridged damp proof course. Rainwater leakage through walls – can be caused by poor pointing, cracked render or leaking gutters. Condensation from high internal humidity levels or poor insulation. Salt contamination from old chimneys.

What are the disadvantages of damp proofing?

Disadvantages
  • Limited to Rising Damp: Damp proof injection primarily addresses rising damp issues and might not be as effective for other types of dampness, such as penetrating damp or condensation.
  • Potential for Incorrect Application: The effectiveness of the injection method heavily relies on the correct application.

What is the problem with damp proof course?

Over the course of 30 years or so, it is possible for a DPC to break down, therefore allowing moisture into the property and causing rising damp. It's also possible for homeowners to unintentionally bridge the DPC, causing similar issues.

How many years does damp proofing last?

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. Rising damp is the movement of moisture through the walls and floors by capillary action.

Does damp proofing really work?

With the right technique and the right brand, yes, damp proof paint can really protect your home against damp. Just remember that ordinary paint will not treat damp or mould problems. It is also important to note that damp proof paint will not work if your property is suffering from structural damage caused by damp.

Try This Before You Spend Money on Damp Problems

What is the alternative to damp proofing?

If you're looking for an alternative to traditional damp-proof membranes, lime render may be the answer. Whilst it has been used for many years, lime render is becoming more popular as a way of providing protection against water penetration and damp problems in buildings.

How long does damp seal last?

The good news is that damp proofing can last for 20 to 30 years or more when done well. Modern buildings have a damp-proof course included as part of the building process. This is a physical barrier within the building walls that prevents water ingress.

What is the average cost of damp proofing?

The average cost to damp proof an average-sized property is around £250-£2000. However, there may be some additional costs that you may also need to think about, such as re-plastering or re-rendering. These additional jobs could increase the overall cost of the work by a substantial amount.

How messy is damp proofing?

Will the damp course installation process be messy? Damp proofing involves some plastering work which means that the old plaster on the walls needs to be fully removed. This process might create some dust but we ensure it is kept to a minimum by using dust sheets, damping down and dust suppression methods.

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

Normally, you may not realise the damp proof course has failed until signs of rising damp begin to appear. If you have rising damp in your home, that means a broken, bridged or missing damp proof course is allowing groundwater access to your ground floor walls through capillary action.

How much does a damp specialist cost?

Damp specialists offer solutions such as damp proofing, waterproofing, and moisture control, ensuring your property remains safe and healthy. Hiring a damp specialist typically costs between £300 and £5,000, though this can increase for larger or more complex projects.

Is damp proof successful?

To an extent, damp-proof paint is effective. Provided you have no existing damp issues and a solid DPC (damp proof course) installed, there is no reason why you can't use damp targeting paint as an added layer of protection. That being said, it is not a fix to existing damp issues which is where many people go wrong.

How to tell if a house has a damp proof course?

All homes built after 1875 should have a damp proof course – this is when it became a compulsory building regulation. You can find it by checking the outside of your house and locating a seal that runs horizontally across the brickwork. It usually sits about 6 inches up from ground level.

What is better damp proofing or waterproofing?

Damp proofing prevents rising moisture from the soil. Waterproofing, on the other hand, stops any moisture and liquids from penetrating your structure. Additionally, waterproofing can withstand hydrostatic pressure, whereas damp proofing is not effective for water under pressure.

Does damp proofing add value to a house?

A property that shows signs of damp, such as mouldy walls or a musty odour, can be a major barrier. Damp proofing your home ensures that these issues are addressed and prevented. This not only makes your property more appealing but can also increase its market value.

What is a negative application of waterproofing?

Negative-side waterproofing is normally done when there is an existing wall and there's no way to get access to the outside (positive-side wall) to waterproof it. A typical example where this situation plays out would be with an existing below-grade, occupied space in a high-rise building in any downtown area.

How long does damp proofing last?

It is important to note that while a properly installed DPC can provide long-lasting protection against moisture penetration, it is not immune to wear and tear over time. Depending on the quality of installation and external factors, a damp proof course typically lasts between 20 to 30 years.

Can you redo a damp proof course?

Installing a New Damp Proof Course

If the property doesn't have a DPC in place or an existing one has failed then you can install a new one using a damp proofing injection cream.

How disruptive is damp proofing?

How disruptive is it to have a damp proof course installed? Unfortunately, there's no easy way to do the works. It does create a lot of mess and dust and it is down to each company to ensure that they take steps to minimise this.

Does homeowners insurance cover damp proofing?

The majority of home insurance policies (covering either the building itself or the contents within it) will not provide you with any compensation for the damage that occurs as a result of rising damp. What's more, it is essential that you report signs of any rising damp to your home insurance provider.

What is the best damp proofing?

No matter what room or property you want to damp-proof, you'll find what you're looking for here.
  • #1 Sika. ...
  • #2 BASF. ...
  • #4 Delta Membrane Systems. ...
  • #5 Triton Chemicals. ...
  • #6 Koster. ...
  • #7 Dryzone. ...
  • #8 Perma Construction Aids. ...
  • #9 Permagard.

Can I damp proof my house myself?

Without the help of a professional, there is no guarantee these will work. In general, whether you can damp proof your home yourself will depend on the type of damp and the cause. For example, condensation can be easily dealt with by adding ventilation.

Can damp proofing fail?

As they're blocking moisture all of the time, they naturally get worn down over decades. The other thing that can accelerate the deterioration of a damp proof course is the presence of too much moisture in the ground. Soil can be oversaturated because of leaking underground pipes.

Does Thompson's water seal stop damp?

Thompson's Water Seal uses a unique micro silicone emulsion to stop water penetration. Apply Water Seal directly onto damp surfaces to provide long lasting waterproof protection within hours.

How many years does tanking last in a house?

How long does tanking last for? Tanking systems can also be utilized in existing basements or cellars, particularly when the external sides are inaccessible. The longevity of these systems can span up to a decade, and with proper installation, they might even endure beyond that.

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