Damp Proof Course Costs

Hi Stables kid,
Whether or not the new damp proof course is actually justified if you are having a chemical injection damp proof course inserted it is strongly recommended that the same company undertake the re-plastering.

The reason for this recommendation is to avoid split liability especially in the case of the long term guarantee issued and which you will be relying upon including if you ever come to sell the property in the future. There are inherent limitations with chemical damp proof course injection systems such that there is a very high reliance upon the re-plastering system to hold back residual dampness within the wall and also to hold salts back including those associated with rising dampness. By far the biggest cause of disputes that I deal with is failure of the re-plastering system to fulfil this design function rather than fault with the injection itself. Failure of the re-plastering can be due to poor workmanship or failure to meet the chemical damp proof course manufacturer's specification which requires a very high standard of workmanship and substrate preperation.

Despite issuing specifications to plasterers they often disregard such specifications and will want paying whilst the plaster is still damp. If the areas fail to dry down or suffer degradation at a later date they will blame anyone but themselves and you as a layperson will have no idea if they have worked to specification or not until it is too late. If things go wrong you are looking at a lot of money and disruption to put it right including re-decoration, removal of second fix joinery such as skirting etc to undertake such re-plastering and if not undertaken by the chemical damp proof course contractor the re-plastering contractor will not be guaranteeing their work for 20-30 years or even one year in some cases.

If there is a problem later on it is highly likely the chemical damp proof course contractor will blame the re-plastering in the first instance if they have not undertaken such work and it will be up to you to prove otherwise which can be very expensive and hard work.

Rentokill being a national company have rates which are not the cheapest but then you are paying for their reputation and confidence that they will be there to put things right should things go wrong at a later date. If you cannot afford their rates then choose a contractor whose rates you can afford for them to undertake both chemical injection and the re-plastering. For piece of mind the preferance is to use a Property Care Association (PCA) Member contractor of which Rentokill as far as I am aware are also Members because the PCA have an arbitration scheme for disputes and their members must be appropriately qualified. Hope this helps David Aldred Independent damp and timber surveyor