A new timber frame construction was erected adjacent to the older cottage and within 20m of the sea - this challenging location has meant that superior building protection solutions were chosen to ensure long term building security.

The Ampack Airtight system was achieved to enerphit levels of airtightness and to manage vapour in the building. External and internal systems were supplied by Ampack care of Partel which essentially ensures the structure avails of the market leading 10 year warranty by Ampack  

Specialist insulation materials were also used to improve the performance. Cellulose insulation pumped at 65kg/m3 was used in the exterior timber frame walls with 100mm of Woodfibre insulation outside of this. The internal service cavity has 50mm flexible woodfibre insulation (both woodfibre and cellulose are used to keep the house cool in the summer).

Thermal bridging was addressed in all areas using Compacfoam underneath the timberframe and doors and the entire roof has woodfibre insulation over the rafters. Heico fixings were used throughout.

The LUNOS decentralised heat recovery ventilation system was chosen due to guaranteed low sound levels, ease of installation and low running costs. We also used the smart LUNOTHERM element.

Internally the soundproofing of floors used a combination the Idikell system from Ampack and 20mm of rigid high density woodfibre insulation.

The project has finished and the results in terms of location and comfort are exceptional.

(Airtightness, Thermal bridging, Windows and Insulation are all in keeping with many passive house projects recently undertaken but certification was not a requirement from the clients. Building performance and comfort were the primary factors)

Project management, specification and supervision by Corbwell Design. Low energy materials and specification by Partel. Original architectural design by others.

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).

Data_sheet_Ampatex_LDA-0.02-plus_lr_en

The Ampack Market leading 10 year warranty covers the cost of removal of all affected material, as well as the replacement of all damaged materials.

10 reasons for an airtight House

1. In the case of new buildings a permanent, airtight layer is now essentially a requirement.
2. New building regulations ensure that the assigned certifier must have correct detailing to avoid future construction damage
3. No draughts
4. Lower heating costs
5. No condensation in the construction
6. No mould formation
7. No damage to the building
8. Clear improvement in the quality of air in the rooms
9. Clear improvement in sound insulation
10. Ventilation systems work highly efficiently

These days, homeowners and clients expect more in terms of quality in their  homes. In particular, they pay special attention to their climate: It has to be comfortable, It should not damp or too dry and the energy costs must be kept within reason. In other words: Everything should be right, with no ifs or buts. Which is one more reason why the construction of new buildings should always be airtight.

Build well, build airtight

Heat loss due to a lack of airtightness is extremely expensive and can potentially cause great damage. The installation of a high quality airtight layer protects both your wallet and the value of the building. The amortisation of the investment over many years is clearly more relevant here than the short-term cost considerations.

Even the smallest joints and tears in the building shell can cause disastrous amounts of damage to a house and result in clearly escalating energy costs.

Construction Damage

Thermography: Blue = heat loss
resulting from ventilation = increase
in energy consumption and structural
damage.

Mould formation within a multi-layer
structural component.

Partel are the exclusive Irish and UK agent for the Ampack range of airtightness, wind-tightness, and building protection products. Ampack was founded in 1946 and is one of Europes most established specialist membrane and tape manufacturers.

“Our Ampack products offer a complete building protection system, from radon membranes to airtight membranes, tapes, adhesives, and wind-tight membranes, and Ampack’s unique 10 year guarantee ensures customers confidence in our range” .

Achieving airtightness for the new building regulations. 

At Partel we have worked on a standardisation of robust airtight details designed to ensure the following: -

1. Compliance with building regulations
2. Quality detailing to achieve excellent blower door results

Our details when applied correctly will always exceed the current building regulations and achieve lower than 0.6 air changes – the passive house standard

All of construction drawings are  available for free download at the links below

• Ampack Masonry construction details
• Ampack Timber frame construction details
• Tender Text External Systems
• Tender Text External Systems

Auto cad drawings available on request – contact us here 

It sounds like an obvious answer but until now very few people even consider it. It is an important part of the construction fabric and although it may not cause the same heat loss or structural damage as ineffective airtightness its benefits should not be overlooked.

This a change in thinking for many professionals who for years have been encouraged to have as much ventilation as possible in the roof space. In the past we were used to bituminous roof felts which created issues with condensation and construction damage and necessitated large amount of in roof ventilation (Wind !)

More recently various qualities of breathable membranes have come to the market which have helped but are not designed to deal with the levels of humidity in the modern homes and may still experience condensation if airtight measures are overlooked.

It is still possible to ventilate the roof as before but this allows the cold air to cool the insulation layer thereby affecting insulation performance. We should also consider that the average family home of 2 adults and 2 children can create 10 Litres of water vapour per day.  Airtight membranes are designed to stop >90% of water vapour and will allow the roof membrane to dry the construction without overloading. Improved results can be achieved by making your construction Windtight and Airtight.

Our windtight membranes (Roof felts) have two purposes – to protect the construction during the construction process and afterwards to form part of a breathable construction that can allow the construction to dry correctly.

Benefits,  Implications  

• Without windtightness U Values can be up to 1.5 times higher than the calculated figures due to thermal bypass
• Thermal bypass can occur when buildings are airtight but not windtight. This weakness allows air to move around or through insulation. In the roof, this occurs when the felt has not been taped or sealed at the eaves.
• Decreases losses associated with possible holes in the insulation layer.
• Decreases the chances of water ingress

Windtight membrane requirements

• Rain tight, airtight,vapour permeable and compatible with the airtight layer (Contact us for free WUFI analysis to ensure correct specification)
• High mechanical strength – Our Ampatop® Aero offers up to 3 times the tear resistance of some commonly used felts – Our higher grade Ampatop Protecta® offers almost 3 times that the tear resistance of Aero, and 5/6 times that of commonly used roof membranes.
• UV Stable, flame resistant, suitable for temperature ranges from -20° C  to +80° C

How to achieve windtight construction at roof level

Option 1

Windtight using Ampatop® Protecta windtight membrane, Ampacoll®XT 60 & Ampacoll® Superfix

Ampacoll® Superfix

Ampacoll®XT 60

Option 2

Windtight using Ampatop® Protecta plus windtight membrane with integrated tapes.

Windtight Accessories

We recommend making all penetrations wind tight and water tight using either  Ampacoll® BK535 – the award winning flexible butyl tape seen here sealing at chimneys and ventilation ducts.

BKF can withstand temperatures from -40° to +90 °C, is highly flexible – (moves with structural elements) and elastic ( can be formed in 3 dimensions)

Ampacoll BK535.

Nail Seals Ampacoll® ND Band

Nail seal tapes avoid rainwater penetration through the nailing and screw-fixing of battens and counter-battens.

Ampacoll® ND Band have a temperature range from- 25 °C up to + 75 °C

See below an extract from our editorial in passive house + magazine

Galway-based company Partel has launched a range of specialist insulation, ventilation, and airtightness systems to the Irish market, aimed specifically at the low energy building sector. The company was founded by Hugh Whiriskey in 2011.

Partel is the exclusive Irish and UK agent for the Ampack range of airtightness, wind-tightness, and building protection products. Ampack was founded in 1946 and is one of Europes most established specialist membrane and tape manufacturers. “Our Ampack products offer a complete building protection system, from radon membranes to airtight membranes, tapes, adhesives, and wind-tight membranes, and Ampack’s unique 10 year guarantee ensures customers confidence in our range” said Hugh Whiriskey.

Partel also supplies the Lunos range of humidity activated decentralised ventilation systems. This range includes the award winning Lunos e2, one of the smallest heat recovery ventilation units in the world. The Lunos e2 system is not only duct free but  can be used in both new and retrofit construction. 

In addition, Partel offers the Schneider range of woodfibre insulation. “Schneider woodfibre is produced in one of the most modern factories in the world; the quality of the products is unparalleled,” Whiriskey said. “They amazingly have a zero waste production plant.” He explained that the woodfibre itself is produced from the by-products of timber production and that the waste from the insulation manufacturing process produces biomass that is then burned to power the plant (the equivilant of a population of 24 million). 

Partel have also partnered with Episat to bring the Epatherm range of calcium silicate insulation boards for use primarily in older buildings. Partel will launch its in-roof solar PV tiles in early September.

Whiriskey said that “As an Engineer with 15 years experience in construction I have found that there is a demand for higher quality building products, and that the focus will continue to move towards natural and sustainable products”. “We offer customised technical sales and provide support on all of our products from specification advice, WUFI analysis, training, and onsite inspections. We believe we have a lot to offer to the modern builder.

In addition to low energy buildings we have a number of Passivhaus and Enerphit projects on our books which we believe is a reflection of the quality of our products and  services”.  

Airtight Supplies

Wood Fibre

Calcium Silicate

Decentralised ventilation

Often referred to as airtight membranes know but should be classified as -

1. Vapour Checks
2. Vapour Barriers

Before we discuss the differences in 1 & 2 we need to discuss Vapour resistance, SD values and μ values.

Vapour resistance

The vapour resistance of a material is a measure of the material’s reluctance to let water vapour pass through. The μ (“mu-value”) of a material is also known as its “water vapour resistance factor”. It is a measure of the material’s relative reluctance to let water vapour pass through, and is measured in comparison to the properties of air. The μ value is a property of the bulk material and needs to be multiplied by the material’s thickness when used in a particular construction. Because the μ value is a relative quantity, it is just expressed as a number (it has no units)

Equivalent air layer thickness (sd value)

You might see the reluctance of a material to let water vapour pass through expressed as an “equivalent air layer thickness”, which is usually represented as sd. As its name suggests, the equivalent air layer thickness is measured in metres. Like vapour resistance, it can only be quoted for a particular thickness of material. The higher the SD Value the more resistant to vapour transmittance.

To convert an equivalent air layer thickness to a µ-value -sd is the symbol for equivalent air layer thickness

Divide by thickness in metres

Example: For a material with : sd = 2,000m and thickness = 100 mm, we have µ-value =2000 m / 0.1 m = 20000

3 Rules for the correct Installation of Vapour Barriers and Vapour Checks

1. Working ventilation or vapour permeable layer. low SD value. DB90, DB2, Sisalex 500

2. No Ventilation between insulation and vapour retardant outer skin.  Vapour barrier  with high SD value Sisalex 514 >1800

3. Locations with constant relative humidity such as swimming pools. Vapour barrier high SD value  Sisalex 514 >1800

Incorrect installation will lead to construction damage!

The images below show roofs where a Vapour check should of been installed.

Incorrect installation or lack of appropriate membranes can cause issues with insulation functioning as specified leading to lower U Values, dampness, and structural damage

What is WUFI
WUFI – Oak Ridge National Laboratory (ORNL)/Fraunhofer Institute for Building Physics (IBP) is a menu-driven PC program which allows realistic calculation of the transient coupled one-dimensional heat and moisture transport in multi-layer building components exposed to natural weather. WUFI-ORNL/IBP is based on the newest findings regarding vapour diffusion and liquid transport in building materials. The underlying model has been validated for over 20 years.

Hygrothermics
Besides the thermal properties of a building component and their impact on heating losses, its hygric behavior has to be considered, too. Permanently increased moisture content in the component may result in moisture damages. Elevated surface moisture levels in living rooms can lead to hygienic problems and health risks due to mould growth.
In addition, thermal and hygric behavior of a building component are closely interrelated as well as an increased moisture content favors heat losses. The thermal situation affects moisture transport. Therefore, both have to be investigated together in their mutual interdependence; the research field of hygrothermics is dealing with these problems.
Out of Date: Dew-Point (Glaser)
The Dew-Point method as detailed in American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) handbook has been a common method to assess the moisture balance of a building component by considering vapour diffusion transport in its interior. However, this method does not allow for the capillary moisture transport in the component, nor for its sorption capacity, both of which reduce the risk of damage in case of condensation. Furthermore, since the method only considers steady-state transport under heavily simplified boundary conditions, it cannot reproduce individual short-term events or allow for rain and solar radiation. It is meant to provide a general assessment of the hygrothermal suitability of a component, not to produce a simulation of realistic heat and moisture conditions in a component exposed to the weather prevailing at its individual location.
Up to Date: WUFI-ORNL/IBP
The menu-driven PC program WUFI-ORNL/IBP developed by the Holzkirchen branch of the Fraunhofer IBP and ORNL validates using data derived from outdoor and laboratory tests, allows realistic calculation of the transient hygrothermal behaviour of multi-layer building components exposed to natural climate conditions.

To meet new U -Values for building regulations, achieve passive levels of airtightness and to minimise thermal bridging should we abandon the cavity wall in favour of timber frame or externally insulated masonry?

There are issues to overcome but what does cavity wall still offer that External Wall Insulation or Timber frame construction does not ?

• Familiarity to Architects, Engineers, Builders, tradesmen and home-owners
• Cost
• Skills
• Knowledge
• Lack of certification for newer products

What are the issues?

• Thermal bridging at Ground, floor, roof, windows and doors.
• Suitability for achieving airtightness
• Breathability
• Speed of construction

We believe that the downturn in economy has negated the issue of speed somewhat and the cost competitive nature of the industry has inspired architects and builders into finding new ways of overcoming the issues with cavity wall construction.

We recently worked with Greentec Eco homes on a passive cavity wall construction project that used quinn lite blocks to minimise thermal bridging at foundation level,  teplo ties as part of a 250mm pumped cavity wall, Ampack Airtight tapes and Membranes  to achieve a passive level air change rate of 0.37 ac/h, and innovative treble wallplate detail free from thermal bridging.

Manufacturers appear to believe the cavity wall is here to stay with Ampack  now producing 4 new airtight window tapes for Ireland and cavity walls – they can be seen here (Ampack Window installation tapes). Aeroboard producing supergrund foundations suitable for masonry, Xtratherm developing and producing Thin-R plus full fill cavity insulation, and teplo ties facilitating full fill cavity insulation up to 300mm.

A paper by Joseph Little of Joseph Little Architects studies the issues in greater detail  and while last updated in 2006 is still worth reading Partial Fill Cavity Walls: Have We Reached the Limits of the Technology? This paper while identifyng the positives and negatives also serves to highlight the changes and solutions that have been developed since 2006.

While timber frame and externally insulated masonry may offer  advantages in terms of speed, suitability for airtightness, and thermal bridging it is clear that the modified cavity wall has a future as it can compete on price, and has greater flexibility for finishes and cladding and is engrained in construction in Ireland and the UK.

Water comes from the outside? Well, yes …. but more moisture might be permeating the construction from inside the building shell than from the weather.
When vapour checks and airtight layers are used in accordance with
the standards, they provide the following benefits:

• Energy losses are reduced
• Condensation is avoided in the structure
• The formation of mould and structural damage is avoided
• Pollutants are avoided in the air within the rooms
• The noise-reduction mass in structural components is guaranteed
• The insulating effect of structural components is guaranteed
• The ability of ventilation systems to work properly is guaranteed

Therefore, it very quickly be comes clear that an incomplete or badly-fitted airtight layer bears a huge risk of damage and danger. We new have the correct membranes available to ensure the above problems do not occur. For more please see www.theinsulationstore.ie

Thermography: Blue = heat loss
resulting from ventilation = increase
in energy consumption and structural
damage.

Mould formation within a multi-layer
structural component.