Do you have damp patches, mould growth, or peeling wallpaper? These problems can be caused by excessive moisture in your walls, and a Damp Proof Membrane (DPM) might be the solution you need.
Why Use a Damp Proof Membrane?
Rising damp and penetrating damp can wreak havoc on your property. A DPM acts as a barrier, protecting your walls from moisture and preventing the following issues:
- Mould growth
- Damp patches
- Salt contamination
- Damaged plaster
- Discolouration
- Blistering paint
- Peeling wallpaper
- Fungal decay
- Damaged interior décor
- Increased heat loss
Identifying the Type of Dampness
Before tackling the problem, it's crucial to identify the type of dampness affecting your walls. Here are the three most common types:
- Rising Damp: Caused by moisture rising from the ground.
- Penetrating Damp: Caused by water ingress from outside, such as leaking pipes or defective guttering.
- Condensation Damp: Caused by excess moisture in the air condensing on cold surfaces.
Damp Proof Membranes are ideal for treating rising damp and penetrating damp.
What is a Damp Proof Membrane?
DPMs are typically made from high-density polyethylene (HDPE) or polypropylene (PP) and come in the form of studded plastic sheets. These studs create an air gap that allows for vapour transmission while keeping moisture at bay.
There are two main types of DPMs:
- Meshed: Designed for use with plaster, render, or plasterboard fixed with adhesive dabs.
- Non-Meshed: Ideal for block walls or dry-lining frames where a render finish is not required.
Benefits of Using a Meshed Damp Proof Membrane
- Easy and quick to install
- No need for extensive wall preparation
- Effective and long-lasting protection against moisture
- Improves thermal performance by reducing heat loss
- Protects your décor and prevents future damp-related problems
How to Install a Meshed Damp Proof Membrane
Preparation:
- Clean the wall surface: Remove loose debris, plaster (if necessary), and any damaged render. Aim for a flat surface.
- Identify and address the source of dampness: A DPM is a treatment, not a cure.
Installation:
- Cutting: Decide whether to install the membrane horizontally or vertically and cut it to size using a sharp utility knife, scissors, or shears.
- Jointing: Overlap and seal horizontal or vertical joints with mesh tape for a secure bond.
- Sealing Protrusions: Use sealing mastic around pipes or other protrusions to prevent moisture bridging.
- Fixing: Ideally, the membrane should extend into ceiling voids and down past the floor slab. If not possible, cut it to fit tightly at the soffit and floor. Apply the membrane flat with studs facing the wall. Use a drill and plugs to fix it securely at a maximum of 250 mm intervals. On uneven surfaces, use closer fixings.
- Finishing: Once the membrane is installed, you can apply various finishes like Whitewall One Coat plaster, render, hydraulic lime, or plasterboard fixed with adhesive dabs.
Additional Tips:
- Maintain a space between the plaster/render and the floor using a finishing profile.
- Apply Whitewall One Coat plaster or render in multiple coats, allowing proper drying time between each.
- Consider using a damp-resistant plaster like Tarmac Whitewall One Coat.
- For rendering, a two-coat system with a scratch coat and a float coat is recommended.
- Hydraulic lime can also be used as a finish.
- Plasterboard can be fixed using the "dot and dab" method with adhesive dabs.
3 Things to Remember:
- Do not apply decorations until the plaster or render is completely dry.
- Hairline cracks can be addressed with fillers or high-build masonry paint.
- Laminated or insulated plasterboard should not be fixed with the "dot and dab" method due to building code requirements.
By following these steps, you can effectively install a Damp Proof Membrane for your home.
Remember: For professional advice or complex damp problems, consult a qualified surveyor or builder.
About DIY Refurb
DIY Refurb is a fast growing provider of building materials and solutions, committed to supplying products that enhance the durability, aesthetics, and environmental footprint of building projects. With a focus on quality and customer satisfaction, DIY Refurb continues to support contractors and private households alike with a range of high quality building supplies.
For further information, please contact:
DIY Refurb
sales@diyrefurb.co.uk
https://diyrefurb.co.uk/
