Posted On By Danny Neill

How To Damp Proof Internal Walls

How To Damp Proof Internal Walls

Author: Danny Neill - Operations Manager at Platinum Chemicals Ltd

How To Damp Proof Internal Walls

Are you finding Dark Patches on your internal walls? Peeling Wallpaper, Blistering Paint or Salt Efflorescence? These are the most common signs of Rising Dampness.

Here we focus on the problems associated with Rising Damp, and more importantly, how to treat the problem.

Rising Damp is a common problem in older properties either because no damp proof course (DPC) was provided at the time of building, or because a physical membrane has failed or been 'bridged'. In the majority of cases the provision of a remedial DPC is a cost effective and minimum disturbance option.

Dampness in buildings, if left untreated, can lead to structural deterioration and  timber decay, spoil decorations and can have problematic health effects through the development of moulds and mites.

The source of rising damp is the soil or subsoils which are always wet. Soils consist of biodegraded plant matter hence water in soils is nor pure and usually contains nitrate and chloride salts. These rise through the masonry and are left behind as water evaporates. Rising damp over a number of years can cause high levels of salts in masonry. These residual salts are hygroscopic, hence they contribute to the problems found.

Rising damp results from the capillary action of water from the ground. In the absence of an adequate DPC a zone rising to around 50cm (or more) above the skirting level along the whole length of the wall will result.

Where the DPC is damaged or breached, patches of dampness may occur.

Initially the Damp Proofing Course needs to be renewed.

What Treatments are Available For Damp Internal Walls?

Available treatments for Rising Damp in walls include:

  • Damp Proof Membranes
  • Damp Proof Creams
  • Damp Proof Injection Fluids
  • Salt Neutraliser
  • Render Additives For Replastering

Damp Proof Membranes

At Platinum Chemicals we specialise in Damp Proof Membranes, we stock a very wide range of Membranes from market leading brands such as our own Platinum Brand, Newton® Waterproofing, Isola Platon® and now Wykamol Brand.

Damp Proof Membranes are used when Damp Proofing above ground walls subject to Rising Damp, Penetrating Damp or Salt Contamination. Read our guide on how to Install Damp proof Membranes.

The installation of a Damp Proof Membrane has many benefits as they provide a surface that is totally separated and unaffected by the dampness within the wall, ensuring that the wall finish will never be affected by moisture or salts if installed correctly.

We supply a wide range of ancillary products for use with Damp Proof Membranes, such as Fixing Plugs and Sealing Tapes.

We also offer Damp Proof Membrane Kits, which are supplied complete with the recommended Fixing Plugs and Sealing Mastic / Washers.

Damp Proof Creams

The injection of a Damp Proof Cream is a very easy solution to treat Rising Damp in Masonry Substrates, having the benefits of a fast injection with little mess and the product itself being low in hazard. Read our guide on how to use Damp Proof Cream

At Platinum Building Chemicals we supply also a wide range of market leading Damp Proof Creams. That can be used in all types of masonry without the use of high pressure equipment. Our product range includes many well known brands such as DampSolve™DampSolve™-40, Dryzone® and Ultracure™.

We also supply a range of Damp Proofing Cream Kits, which include the DPC Injection Cream in a range of cartridge sizes, the required Applicator(s) and Drill Bits.

Damp Proof Injection Fluids

Damp Proof Fluids are intended for injection into walls affected by rising dampness.

Damp Proof Fluids are injected through pre-drilled holes formed either in bricks or the mortar joints to form a continuous barrier against water rising from the ground.

Our range of BBA Approved Damp Proofing Fluids include Aqueous Based TRIJECT 3 and Siliconate K, both of which dilute with water to give you a 25 Litre ready-to-use solution.

We also have DPC No. 1, an organic Solvent-Based Stearate Resin (POAS) solution, supplied in a 25 Litre Container, ready to use.

Salt Neutraliser

Due to rising dampness, salts contained in ground water are absorbed into the masonry and subsequently into the plaster coat.

If the rising damp had been severe the plasterwork can lose key and visual evidence of this problem can often be noted by the presence of salt deposits.

Salt Neutraliser is used to overcome the problem of salts in a wide range of substrates from new plasterwork to old stone

Render Additives for Re-plastering

After a Chemical DPC, efflorescent salts are often left behind in the wall which are harmful to the plaster finish, leaving the appearance of damp patches.

A suitable re-plastering specification must therefore be used, including a salt inhibiting and waterproofing product such as RenderProof and Renderguard Gold.

This product prevents passage of residual ground salts which are harmful to plaster finishes.

Need Technical Advice?

If you think you may have Rising Damp, but unsure what to do next? Please do not hesitate to us call on 01355 222777 for free impartial advice. We would be more than happy to assist with any questions you may have.

Alternatively you can email us at

Not every form of 'dampness' relates to Rising Damp. It may be problems associated with Penetrating Dampness or even Condensation Dampness, so it is important to identify exactly what the problem is, and we are here to help.

Main Image Credit: kebabknight; Wykamol; Russell Preservation

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