Wednesday 31 May 2017

Cavity Drain Membrane Waterproofing vs Traditional Tanking

Benefits of Cavity Drain Membrane Waterproofing


Oldroyd Cavity Drain Membranes


(To view this blog with images please visit Conifer Property Services)
  
Hello again! As you will be aware if you have glanced through our web site, we get involved in all sorts of damp proofing and use all sorts of materials to treat the various problems we come across. We speak to people all over the country and it is fair to say that the existence of most of the membranes we use is still not widely known. The broad perception of damp proofing is still that you get your walls injected and that's it!

For some applications injection and waterproof render, or one of our new damp resistant plasters, is still the weapon of choice of course. We normally install Dryzone Dryrods these days as they get exactly the right amount of product into the wall. Also, when tanking a basement or any wall built into a bank the Vandex slurry systems we install can be ideal but there is a suite of materials that can cover both of these functions when conditions are right.

So if you are considering getting some damp/waterproofing work carried out there can be several advantages to a membrane system. We thought we would list some of them for your consideration:

The Oldroyd Cavity Drain Membrane System provides the following benefits:


1) There is no pressure on the damp proofing system or the structure, the water is simply allowed to follow the easy path back to the ground;

2) The walls are still allowed to breathe as there is at least 5 litres of air per sqm (often more) behind the membrane, this space can be sealed or vented as required;

3) Environmental note: In addition to its damp proofing properties, the membrane creates a small air gap, due to its profiled shape; this improves the U-Value of the wall. If unventilated, the air gap is not big enough to allow convection and so is an effective reducer of heat loss (double glazing works in a similar way). This coupled with plasterboard fitted using the 'dot and dab' method (if appropriate) gives two cavities in an otherwise solid wall which is beneficial in two ways.

Firstly the cavities create a thermal barrier, as stated, which helps with the energy efficiency of the building.

Secondly, because the surface of the wall is not cold due to this cushion of air, this greatly combats condensation which is of course a major cause of the more obvious signs of dampness such as mould and smells; Even without secondary insulation the membrane system will help to make the building more 'energy efficient' and take away the cold clamminess to the exterior walls making them feel warmer to the touch.

This coupled with the eradication of damp and associated smells in the atmosphere all helps to make a healthier, more comfortable environment. Oldroyd membranes are made of 70% recycled material and are recyclable again at the end of their intended life-spans (more than 50 years expected).

4) The Oldroyd membrane system is resistant to sulphate attack so all internal finishes will be fully protected from hydroscopic salts for decades.

5) Often, little or no preparation is required, the membrane can go straight over existing plasters and wall coverings as long as they are reasonably sound. As well as saving a lot of mess and waste, removing a decent, if damp, render can often leave the wall in a weaker state;

6) Traditional cementitious methods are mixed by hand and as such are susceptible to imperfections, they are constantly under pressure to repel water which also retains the water in the wall (this can lead to frost damage, structural loading and other problems) and also they have a much shorter intended lifespan – Oldroyd membranes have none of these problems;

7) Membranes are flexible and will not crack or leak during the seasonal movement usually found in old buildings. If a traditional, waterproof render cracks water will find a way through to the plaster again and cause dampness issues.

We also install the fairly new Drybase Flex Membrane system which also has unique benefits listed below:


1) The Drybase Flex Membrane System is resistant to sulphate attack so all internal finishes will be fully protected from hydroscopic salts for decades;

2) The membrane is chiefly designed to stick to exposed brickwork, but on occasion little or no preparation is required as the membrane can go straight over existing plasters and wall coverings as long as they are structurally sound and free of paint, etc. - a judgement should be made on this prior to commencement. As well as saving a lot of mess and waste, removing a decent, if damp, render can often leave the wall in a weaker state;

3) Traditional cementitious methods are mixed by hand and as such are susceptible to imperfections, they are constantly under pressure to repel water which also retains the water in the wall (this can lead to frost damage and other problems) and also they have a much shorter intended lifespan – Drybase membranes have none of these potential problems;

4) Membranes are flexible and will not crack or leak during the seasonal movement usually found in old buildings. If a traditional, waterproof render cracks water will find a way through to the plaster again and cause dampness issues. The fleece on the front and back of the Drybase Flex Membrane acts as a decoupling agent allowing slippage to further resist possible plaster cracking due to structural movement;


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