How do DPC creams work?

In today’s edition of Built to Protect, we’re putting on our lab coats to delve into how chemical damp-proof courses (DPC) work to protect homes from rising damp. Later on in the newsletter, get all the details on our latest CPD webinar: Mould and Condensation on Tuesday 19th March 2024.?

A chemical Damp-Proof Course (DPC) is a hydrophobic barrier that stops rising damp. In buildings without a physical DPC, or where a physical DPC has failed and replacement is not an option, a chemical DPC is the best way to establish a new damp-proof course.

Generally, a chemical DPC installation involves drilling regular holes into the mortar course to inject either a cream or liquid into the wall. When the treatment cures, it diffuses throughout the wall to establish a damp-proof barrier.

Whereas it is obvious how a physical plastic Damp-Proof Membrane (DPM) can stop moisture, it is less clear how a DPC cream can stop moisture in the same way.?

The science behind chemical DPC creams

Once the DPC cream is injected into the mortar course, the active ingredients of the cream will diffuse into the wall and chemically react with the minerals inside to form hydrophobic chains of molecules. With the correct amount of the right active ingredients placed at 150 mm above ground level (as per Building Regulations Approved Document C), an unbroken DPC can be established across the whole length of the wall.

Dryzone Damp-Proofing Cream is made from silane and siloxane to form an emulsion cream. These two chemicals are types of silicone, which makes them great at repelling moisture.?

Silane molecules are tiny, which lets them penetrate deeply into mortar. Once injected into an alkaline environment like mortar with portland cement, the silanes transform into silanol polymers. When the cream dries, these polymers condense into polysiloxanes. These polymers bond to mortar pores to make them water-repellent.

Siloxane polymers form the cream vehicle that carries silane through the mortar course. You probably use siloxanes daily; they’re common ingredients in shampoos and conditioners. Here, siloxane polymers enable Dryzone Damp-Proofing Cream’s ease-of-use and mess-free application.?

This carefully formulated and high strength balance of silane and siloxane ensures that Dryzone Damp-Proofing Cream is user-friendly while maintaining high performance. The Dryzone silane/siloxane formulation has been expertly calculated for maximum spread and exceptional performance across all property types and ages.

Dryzone DPC Cream: tested to work

Although lower strength silane/siloxane formulations spread throughout the wall, they lack the strength to successfully establish a working chemical DPC. They also cure slower generally. Like a hole in the bottom of your boot, it lets in water; resulting in a failed damp-proof course.

In an independent study conducted by the University of Portsmouth, Dryzone DPC Cream was tested against a lower-strength formulation that contained just 15-20% active ingredient.?

The Portsmouth team prepared lime mortar bricks with each of the formulations, let them fully cure then saturated them in water. The results found that a low-strength cream caused 60% water saturation in the test brick, proving that a lower-strength cream is not sufficiently water-repellent to establish an effective damp-proof course.

Only the right balance of silane/siloxane can establish a strong and resilient chemical damp-proof course. That’s why Dryzone Damp-proofing Cream is the optimal choice for your remedial chemical damp-proof course.

Want to know more about Dryzone's certifications? Read this.

Mould and Condensation in Buildings CPD webinar

In 2024, we know more than ever about the harmful effects of damp and mould on human health. In this one-hour session, equip yourself to become a part of the solution by learning:

• The science behind condensation and mould growth
• How to prevent mould growth by controlling condensation generation
• How to safely clean a mouldy environment
• The health and structural impacts of excess condensation and mould growth

This information should be accessible to all. That’s why all our CPD webinars are free. Whether you’re a professional in the built environment or you simply want to know more about mould growth, everyone is welcome. We hope to see you on Tuesday!

Sign up for our next free RIBA-approved CPD webinar: Tuesday 19th March at 1 PM?

That’s it for another edition of Built to Protect! Let us know your thoughts in the comments or send us a message at info@safeguardeurope. For all technical questions or sales enquiries, phone us on 01403 210204.