Partel » retrofit

Ampatex® LDA 0.02 plus – Renovation Vapour check

Hugh — Wed, 02 Sep 2015 21:48:59 +0000

Ampatex® LDA 0.02 plus - Renovation Vapour check

What is it and why is it changing how we upgrade older homes?

We are used to seeing SD values in airtight membranes – LDA is different in that it lists an a value – 0.004m3/(h*m2). The a value describes the quantity of air passing through the layer. (The SD vale relates to the humidity or vapour). While the a value is not currently a defined standard the reference value in the industry for an airtight layer is <0.01m3/m2/h.

This solution starts with higher humiditys and the quality of application is (As it is with all VCL’s) important. To assist with this AMPACK have include integrated tapes on both sides of the membrane and has the same incredible strength we have become accustomed to from AMPACKs exterior membranes.

When we consider quality of application is is important to understand why – a 1mm wide gap can allow 360g water per day – such errors can create issues in any VCL system and as always we recommend a blower door test. In this case it should be carried out when LDA has been installed and before the windtight membrane (PROTECTA is installed).

With AMPACK this is a system solution – below you can see that LDA is compatible with BBA certified Protecta and its associated rane – XT, and Superfix.

From a technical point of view the thickness of the SCHNEIDER Woodfibre insulation plays an important part – We analysed the systems for the demonstrated room in WUFI and found that 35mm of woodfibre was insufficient and led to unacceptable water content for short periods – when we increased the system as below – 60mm woodfibre or more the system is within acceptable parameters. We recommend that 80mm of SCHNEIDER 140 multitherm be installed generally.

This system has obvious benefits in addition to airtightness as it achieves a thermal bridge free roof, offers excellent decrement delay (Keeps house cool in the summer) and actually sequesters carbon.

Data_sheet_Ampatex_LDA-0.02-plus_lr_en

A new way to achieve Airtightness in retrofits

Hugh — Wed, 02 Sep 2015 21:21:36 +0000

How to achieve airtightness in retrofits ? Its a common question asked of us here at Partel. Until now there were only 2 options available to us – Thanks to an Innovative new product from AMPACK we have a third possible solution. Read about the unique AMPACK LDA membrane here

The system many have become accustomed to is the easy one – where we have full and unobstructed access internally - in this situation its possible to install and test without any issues – Here we use either AMPACK VARIANO – Moisture variable airtight membrane or AMPACK DB90 – Fixed sd airtight membrane.

Option 1 Renovation from the inside – The easy option ?!

Airtightness Layer Ampatex® DB90 or Variano

This is undoubtedly the preferred option for installers and one that is easily tested – inspected, specified but unfortunately for the home-owner by far the most invasive. In fact its often the case that airtightness is deemed as unachievable due to the disruption caused to achieve this – If you want an easier option – keep reading…

Option 2 – Renovation from the outside

Airtightness Layer Resano (Ampatex® Variano)

From the photos below its clear that this method is somewhat invasive and would require a suitable support system – something that is not common in the UK and Ireland – In fact while the solution is possible it would be rare to find suitable properties for this system.

Option 3 -Renovation from the outside using Ampatex® LDA 0.02

This new solution from Ampack allows us to keep the existing in roof insulation – change the existing roof membrane to AMPACKS LDA 0.02 to give an airtight seal – from here we install approximately 80mm of woodfibre insulation – the thickness of insulation, the type (SCHNEIDER woodfibre) and the unique properties of the membrane combine to achieve a technically safe solution. This solution is explained in greater detail in our next blog post. As always if you have technical queries let us know.