The cavity wall is an integral part of the Irish construction industry – it accounted for approximately 75% of new housing before the start of the recession and has increased as the self build percentage of new builds has increased.
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.
Author: Hugh
Hugh is the founder of Partel, an engineer with 20 years of low energy construction experience. He is a certified passive house designer with genuine passive house construction experience, a detailed knowledge of ventilation, natural insulation and thermal bridging. Hugh is a long time user and advocate of WUFI.
Hi,
Is the upcoming 1 day course in Mountrath CPD accredited? Is there a cost associated?
Kind Regards,
Joe Beggan
Joe,
Just to confirm that we have a course confirmed for the 4th April. Details available here
4th April 2013
AIR & WIND TIGHTNESS & INSULATION
Location METAC Training
Mountrath Enterprise Park,
Portlaoise Road,
Mountrath,
Co. Laois.
Introduction
• Over View of Insulation properties, including U, R and K Values.
• Insulation advantages and disadvantages along with all environmental impacts.
• Natural Insulations and Responsible specification
Air-Tightness & its execution on site
• Introduction to Air-tightness
• Air-tightness & Building Regulations
• Condensation dangers and their impacts
• Ventilation considerations
• Intelligent moisture management
• Conventional Details for Irish Construction
• Material specifications for specific Air-tightness applications
• Questions and answers
Hands on Practical Application and Demonstrations
• Insulation demonstrations for roofs, walls and floors
• Practical Air-tightness installation with Ampack Air-tightness membranes
• Practical Air-tightness to windows and membrane penetrations with Ampack window tapes.
• Practical Wind-tightness installation with Ampack Wind-tightness membranes & Tapes
• Summary/Questions and answers
Booking details Course Duration: 1 full day
Course Cost: €65 (Includes Lunch)
Dates: 4th April 2013
Certification: Ampack Certification, certificate of attendance & Completion CPD available on completion
*Each participant will receive a sample pack with material samples brochures and an Irish detail hand book
To join our training programme contact TIS on 0818 333355 or email sales@theinsulationstore.ie
Hi Joe,
Our Ampack certified course will be CPD accredited.
Our 1 day course costs €65.00 including lunch.
The course cover the technical and practical aspects of
· Insulation
· Airtight Tapes and Membranes – theory and practice
· Windtight tapes and membranes – theory and practice
Location : Metac, Mountrath, Co. Laois.
The next course date is likely to be on the 4th April (To be confirmed next week)
Ill post details here when confirmed or feel free to contact us.
Kind regards
Hugh Whiriskey
T.I.S. Insulation and Building protection